Bound tokenizer merges count to INT32_MAX like the tokens table#548
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gigioneggiando wants to merge 1 commit into
Open
Bound tokenizer merges count to INT32_MAX like the tokens table#548gigioneggiando wants to merge 1 commit into
gigioneggiando wants to merge 1 commit into
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vocab_load() validates the token table with tokens.len > INT32_MAX but omits the same bound on the merges table. The merge loop then stores each rank with table_put(&vocab->merge_rank, merge, (int)i), narrowing the uint64 index to int. A GGUF declaring more than INT32_MAX merges makes (int)i wrap negative and stores corrupt ranks. Mirror the tokens sibling's bound on merges.len.
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Summary
vocab_load()validates the token table withtokens.len > INT32_MAX, but the merges table validation omits the same bound. The merge loop then stores each rank with:A GGUF declaring more than
INT32_MAXmerges makes(int)iwrap negative and stores corrupt merge ranks (affecting tokenization correctness).Fix
Mirror the
tokenssibling's bound: rejectmerges.len > INT32_MAXin the merges validation.Verification
Source-confirmed and compile-checked (the patched translation unit builds cleanly under the ASan/UBSan flags). I did not build a runtime PoC — it would require a crafted GGUF declaring >2³¹ merge entries, which isn't practical to materialize as a file. The
(int)inarrowing and the missing bound (vs the present one ontokens.len) are visible directly invocab_load.Found during a coordinated security review of ds4.