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If the alloc_state is reused, ALLOC_GROW() can wrongly assume that the slab array is already allocated because slab_alloc still holds a stale nonzero capacity. In that case s->slabs remains NULL and the next dereference writes through a NULL pointer, causing undefined behavior. To fix this, we reset slab_alloc, nr, and p to zero/NULL after freeing the slabs. This leaves alloc_state in a consistent empty state for reuse and avoids dangling pointers. Signed-off-by: Noura EL ALLAM --- Reset slab_alloc and state fields in clear_alloc_state() Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2040%2Fnouraellm%2Ffix-dangling-pointer-v1 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2040/nouraellm/fix-dangling-pointer-v1 Pull-Request: https://github.com/git/git/pull/2040 alloc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/alloc.c b/alloc.c index 377e80f5dda..6bf9421c123 100644 --- a/alloc.c +++ b/alloc.c @@ -49,6 +49,9 @@ void clear_alloc_state(struct alloc_state *s) } FREE_AND_NULL(s->slabs); + s->slab_alloc = 0; + s->nr = 0; + s->p = NULL; } static inline void *alloc_node(struct alloc_state *s, size_t node_size) base-commit: f814da676ae46aac5be0a98b99373a76dee6cedb -- gitgitgadget