"bpf: Reject negative const offsets for buffer pointers" test on v6.18#9
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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Replace bpf_strlcpy() in bpf_util.h with a sized_strscpy(), which is a simplified sized_strscpy() from the kernel (lib/string.c [1]). It: * takes a count (destination size) parameter * guarantees NULL-termination * returns the number of characters copied or -E2BIG Re-define strscpy macro similar to in-kernel implementation [2]: allow the count parameter to be optional. Add #ifdef-s to tools/include/linux/args.h, as they may be defined in other system headers (for example, __CONCAT in sys/cdefs.h). Fixup the single existing bpf_strlcpy() call in cgroup_helpers.c [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/string.c?h=v6.19#n113 [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/string.h?h=v6.19#n91 Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev> Link: https://lore.kernel.org/r/20260223190736.649171-2-ihor.solodrai@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This reverts commit adaee08, which came from upstream commit b0388ba ("verifier: Relax scalar id equivalence for state pruning"). but linux-6.18.y is missing the preceeding commits from the same patchset: - 3cd5c89 bpf: verifier: Assign ids on stack fills - b2a0aa3 bpf: verifier: Clear singular ids for scalars Take the conservative approach of reverting the relaxation. While a direct revert does not apply cleanly due to additional changes introduced to regsafe() with commit bc308be ("bpf: Fix sync_linked_regs regarding BPF_ADD_CONST32 zext propagation"), the pre-b0388bafa494 regsafe() actually already require BPF_ADD_CONST flags to match exactly. Hence restoring regsafe() to pre-b0388bafa494 is the correct approach here. Cc: Puranjay Mohan <puranjay@kernel.org> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
commit 086c99f upstream. Before the last commit, sync_linked_regs() corrupted the register whose bounds are being updated by copying known_reg's id to it. The ids are the same in value but known_reg has the BPF_ADD_CONST flag which is wrongly copied to reg. This later causes issues when creating new links to this reg. assign_scalar_id_before_mov() sees this BPF_ADD_CONST and gives a new id to this register and breaks the old links. This is exposed by the added selftest. Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Tested-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20260115151143.1344724-3-puranjay@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
…ropagation commit 4a04d13 upstream. Add multiple test cases for linked register tracking with alu32 ops: - Add a test that checks sync_linked_regs() regarding reg->id (the linked target register) for BPF_ADD_CONST32 rather than known_reg->id (the branch register). - Add a test case for linked register tracking that exposes the cross-type sync_linked_regs() bug. One register uses alu32 (w7 += 1, BPF_ADD_CONST32) and another uses alu64 (r8 += 2, BPF_ADD_CONST64), both linked to the same base register. - Add a test case that exercises regsafe() path pruning when two execution paths reach the same program point with linked registers carrying different ADD_CONST flags (BPF_ADD_CONST32 from alu32 vs BPF_ADD_CONST64 from alu64). This particular test passes with and without the fix since the pruning will fail due to different ranges, but it would still be useful to carry this one as a regression test for the unreachable div by zero. With the fix applied all the tests pass: # LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t verifier_linked_scalars [...] ./test_progs -t verifier_linked_scalars #602/1 verifier_linked_scalars/scalars: find linked scalars:OK #602/2 verifier_linked_scalars/sync_linked_regs_preserves_id:OK #602/3 verifier_linked_scalars/scalars_neg:OK #602/4 verifier_linked_scalars/scalars_neg_sub:OK #602/5 verifier_linked_scalars/scalars_neg_alu32_add:OK #602/6 verifier_linked_scalars/scalars_neg_alu32_sub:OK #602/7 verifier_linked_scalars/scalars_pos:OK #602/8 verifier_linked_scalars/scalars_sub_neg_imm:OK #602/9 verifier_linked_scalars/scalars_double_add:OK #602/10 verifier_linked_scalars/scalars_sync_delta_overflow:OK #602/11 verifier_linked_scalars/scalars_sync_delta_overflow_large_range:OK #602/12 verifier_linked_scalars/scalars_alu32_big_offset:OK #602/13 verifier_linked_scalars/scalars_alu32_basic:OK #602/14 verifier_linked_scalars/scalars_alu32_wrap:OK #602/15 verifier_linked_scalars/scalars_alu32_zext_linked_reg:OK #602/16 verifier_linked_scalars/scalars_alu32_alu64_cross_type:OK #602/17 verifier_linked_scalars/scalars_alu32_alu64_regsafe_pruning:OK #602/18 verifier_linked_scalars/alu32_negative_offset:OK #602/19 verifier_linked_scalars/spurious_precision_marks:OK #602 verifier_linked_scalars:OK Summary: 1/19 PASSED, 0 SKIPPED, 0 FAILED Co-developed-by: Puranjay Mohan <puranjay@kernel.org> Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20260319211507.213816-2-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
commit 1b32773 upstream. When a non-{add,sub} alu op such as xor is performed on a scalar register that previously had a BPF_ADD_CONST delta, the else path in adjust_reg_min_max_vals() only clears dst_reg->id but leaves dst_reg->delta unchanged. This stale delta can propagate via assign_scalar_id_before_mov() when the register is later used in a mov. It gets a fresh id but keeps the stale delta from the old (now-cleared) BPF_ADD_CONST. This stale delta can later propagate leading to a verifier-vs- runtime value mismatch. The clear_id label already correctly clears both delta and id. Make the else path consistent by also zeroing the delta when id is cleared. More generally, this introduces a helper clear_scalar_id() which internally takes care of zeroing. There are various other locations in the verifier where only the id is cleared. By using the helper we catch all current and future locations. Fixes: 98d7ca3 ("bpf: Track delta between "linked" registers.") Reported-by: STAR Labs SG <info@starlabs.sg> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20260407192421.508817-2-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> [shung-hsi.yu: `delta` field was called `off` before commit 3d91c61 ("bpf: rename bpf_reg_state->off to bpf_reg_state->delta"), and clear_singular_ids() does not exists before commit b2a0aa3 ("bpf: verifier: Clear singular ids for scalars").] Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
commit ed2eecd upstream. Extend the verifier_linked_scalars BPF selftest with a rX += rX test such that the div-by-zero path is rejected in the fixed case. # LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t verifier_linked_scalars [...] ./test_progs -t verifier_linked_scalars #612/1 verifier_linked_scalars/scalars: find linked scalars:OK #612/2 verifier_linked_scalars/sync_linked_regs_preserves_id:OK #612/3 verifier_linked_scalars/scalars_neg:OK #612/4 verifier_linked_scalars/scalars_neg_sub:OK #612/5 verifier_linked_scalars/scalars_neg_alu32_add:OK #612/6 verifier_linked_scalars/scalars_neg_alu32_sub:OK #612/7 verifier_linked_scalars/scalars_pos:OK #612/8 verifier_linked_scalars/scalars_sub_neg_imm:OK #612/9 verifier_linked_scalars/scalars_double_add:OK #612/10 verifier_linked_scalars/scalars_sync_delta_overflow:OK #612/11 verifier_linked_scalars/scalars_sync_delta_overflow_large_range:OK #612/12 verifier_linked_scalars/scalars_alu32_big_offset:OK #612/13 verifier_linked_scalars/scalars_alu32_basic:OK #612/14 verifier_linked_scalars/scalars_alu32_wrap:OK #612/15 verifier_linked_scalars/scalars_alu32_zext_linked_reg:OK #612/16 verifier_linked_scalars/scalars_alu32_alu64_cross_type:OK #612/17 verifier_linked_scalars/scalars_alu32_alu64_regsafe_pruning:OK #612/18 verifier_linked_scalars/alu32_negative_offset:OK #612/19 verifier_linked_scalars/spurious_precision_marks:OK #612/20 verifier_linked_scalars/scalars_self_add_clears_id:OK #612/21 verifier_linked_scalars/scalars_self_add_alu32_clears_id:OK #612 verifier_linked_scalars:OK Summary: 1/21 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20260407192421.508817-3-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> [shung-hsi.yu: missing context from commit 223ffb6 ("selftests/bpf: add reproducer for spurious precision propagation through calls").] Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
commit cac16ce upstream. Extend the verifier_linked_scalars BPF selftest with a stale delta test such that the div-by-zero path is rejected in the fixed case. # LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t verifier_linked_scalars [...] ./test_progs -t verifier_linked_scalars #612/1 verifier_linked_scalars/scalars: find linked scalars:OK #612/2 verifier_linked_scalars/sync_linked_regs_preserves_id:OK #612/3 verifier_linked_scalars/scalars_neg:OK #612/4 verifier_linked_scalars/scalars_neg_sub:OK #612/5 verifier_linked_scalars/scalars_neg_alu32_add:OK #612/6 verifier_linked_scalars/scalars_neg_alu32_sub:OK #612/7 verifier_linked_scalars/scalars_pos:OK #612/8 verifier_linked_scalars/scalars_sub_neg_imm:OK #612/9 verifier_linked_scalars/scalars_double_add:OK #612/10 verifier_linked_scalars/scalars_sync_delta_overflow:OK #612/11 verifier_linked_scalars/scalars_sync_delta_overflow_large_range:OK #612/12 verifier_linked_scalars/scalars_alu32_big_offset:OK #612/13 verifier_linked_scalars/scalars_alu32_basic:OK #612/14 verifier_linked_scalars/scalars_alu32_wrap:OK #612/15 verifier_linked_scalars/scalars_alu32_zext_linked_reg:OK #612/16 verifier_linked_scalars/scalars_alu32_alu64_cross_type:OK #612/17 verifier_linked_scalars/scalars_alu32_alu64_regsafe_pruning:OK #612/18 verifier_linked_scalars/alu32_negative_offset:OK #612/19 verifier_linked_scalars/spurious_precision_marks:OK #612/20 verifier_linked_scalars/scalars_self_add_clears_id:OK #612/21 verifier_linked_scalars/scalars_self_add_alu32_clears_id:OK #612/22 verifier_linked_scalars/scalars_stale_delta_from_cleared_id:OK #612/23 verifier_linked_scalars/scalars_stale_delta_from_cleared_id_alu32:OK #612 verifier_linked_scalars:OK Summary: 1/23 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20260407192421.508817-4-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
commit c3d5ef291a2a335d2e33fe75b3b3806fdbd86ad1 upstream. Add a verifier test where a spilled scalar is filled once via a sign- extending load (BPF_MEMSX) and once via a zero-extending load (BPF_MEM). The two destination registers must not share a scalar id. # LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t verifier_scalar_ids [...] #643/1 verifier_scalar_ids/linked_regs_bpf_k:OK #643/2 verifier_scalar_ids/linked_regs_bpf_x_src:OK #643/3 verifier_scalar_ids/linked_regs_bpf_x_dst:OK #643/4 verifier_scalar_ids/linked_regs_broken_link:OK #643/5 verifier_scalar_ids/precision_many_frames:OK #643/6 verifier_scalar_ids/precision_stack:OK #643/7 verifier_scalar_ids/precision_two_ids:OK #643/8 verifier_scalar_ids/linked_regs_too_many_regs:OK #643/9 verifier_scalar_ids/linked_regs_broken_link_2:OK #643/10 verifier_scalar_ids/cjmp_no_linked_regs_trigger:OK #643/11 verifier_scalar_ids/check_ids_in_regsafe:OK #643/12 verifier_scalar_ids/check_ids_in_regsafe_2:OK #643/13 verifier_scalar_ids/no_scalar_id_for_const:OK #643/14 verifier_scalar_ids/no_scalar_id_for_const32:OK #643/15 verifier_scalar_ids/ignore_unique_scalar_ids_cur:OK #643/16 verifier_scalar_ids/ignore_unique_scalar_ids_old:OK #643/17 verifier_scalar_ids/two_nil_old_ids_one_cur_id:OK #643/18 verifier_scalar_ids/two_old_ids_one_cur_id:OK #643/19 verifier_scalar_ids/linked_regs_and_subreg_def:OK #643/20 verifier_scalar_ids/ldsx_fill_scalar_id_not_shared:OK #643 verifier_scalar_ids:OK Summary: 1/20 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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Jul 22, 2026
[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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Jul 22, 2026
[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
kernel-patches-daemon-bpf Bot
pushed a commit
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Jul 22, 2026
[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
kernel-patches-daemon-bpf Bot
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Jul 23, 2026
[ Upstream commit b23705e ] strset_add_str_mem() might reallocate the strset data buffer in order to accommodate the provided string 's'. However, if 's' points to a string already present in the buffer, it becomes dangling after the realloc. This leads to a use-after-free when attempting to memcpy() the string into the new buffer. One scenario that triggers this problematic path is when resolve_btfids attempts to patch kfunc prototypes using existing BTF parameter names: | resolve_btfids: function bpf_list_push_back_impl already exists in BTF | Segmentation fault (core dumped) Compiling resolve_btfids with fsanitize=address generates a detailed report of the UAF: | ================================================================= | ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 | ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818 | READ of size 5 at 0x7f4c4a500bd4 thread T0 | #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7) | #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2 | #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8 | #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14 | #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9 | #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9 | #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6 | #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 | #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3 | #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860) | | 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8) | freed by thread T0 here: | #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700) | #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9 | #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13 | | previously allocated by thread T0 here: | #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3) | #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20 While resolve_btfids could be refactored to avoid this call path, let's instead fix this issue at the source in strset__add_str() and avoid similar scenarios. Let's check if set->strs_data was reallocated and whether 's' points to an internal string within the old strset buffer. In such case, 's' is reconstructed to point to the new buffer. While already here, also fix strset__find_str() which suffers from the same problem by factoring out the common operations into a new helper function strset_str_append(). Fixes: 90d76d3 ("libbpf: Extract internal set-of-strings datastructure APIs") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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bpf: Reject negative const offsets for buffer pointers