ext/dom: fix UAF when setting an attribute colliding by local name.#22452
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devnexen wants to merge 1 commit into
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ext/dom: fix UAF when setting an attribute colliding by local name.#22452devnexen wants to merge 1 commit into
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Fix php#22447 xmlHasProp() matches an attribute by local name only, ignoring its namespace, whereas xmlAddChild()/xmlAddPrevSibling() dedup an incoming no-namespace attribute via xmlHasNsProp(..., NULL), which matches only attributes with no namespace. When both a no-namespace and a namespaced attribute share a local name, the pre-insertion check unlinked the wrong (namespaced) attribute, leaving libxml to free the still-wrapped no-namespace duplicate and producing a use-after-free at request shutdown. Use xmlHasNsProp(..., NULL) so the pre-insertion check matches libxml's internal duplicate detection, as advised by @nwellnhof. close phpGH-22452
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Fix #22447
xmlHasProp() matches an attribute by local name only, ignoring its namespace, whereas xmlAddChild()/xmlAddPrevSibling() dedup an incoming no-namespace attribute via xmlHasNsProp(..., NULL), which matches only attributes with no namespace. When both a no-namespace and a namespaced attribute share a local name, the pre-insertion check unlinked the wrong (namespaced) attribute, leaving libxml to free the still-wrapped no-namespace duplicate and producing a use-after-free at request shutdown.
Use xmlHasNsProp(..., NULL) so the pre-insertion check matches libxml's internal duplicate detection, as advised by @nwellnhof.