From 5e2feb5ca692c5c4d39b11e1ffa056911dd7dfd3 Mon Sep 17 00:00:00 2001 From: ノウラ | Flare Date: Thu, 4 Sep 2025 17:44:16 +0000 Subject: alloc: fix dangling pointer in alloc_state cleanup MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit All callers of clear_alloc_state() immediately free what they cleared, so currently it does not hurt anybody that the alloc_state is left in an unreusable state, but it is an error-prone API. Replace it with a new function that clears but in addition frees the structure, as well as NULLing the pointer that points at it and adjust existing callers. As it is a moral equivalent of FREE_AND_NULL(), except that what it frees has internal structure that needs to be cleaned, allow the helper to be called twice in a row, by making a call with a pointer to a pointer variable that already is NULLed. While at it, rename allocate_alloc_state() and name the new function alloc_state_free_and_null(), to follow more closely the function naming convention specified in the CodingGuidelines (namely, functions about S are named with S_ prefix and then verb). Signed-off-by: ノウラ | Flare Helped-by: Jeff King Signed-off-by: Junio C Hamano --- alloc.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'alloc.c') diff --git a/alloc.c b/alloc.c index 377e80f5dd..533a045c2a 100644 --- a/alloc.c +++ b/alloc.c @@ -36,19 +36,25 @@ struct alloc_state { int slab_nr, slab_alloc; }; -struct alloc_state *allocate_alloc_state(void) +struct alloc_state *alloc_state_alloc(void) { return xcalloc(1, sizeof(struct alloc_state)); } -void clear_alloc_state(struct alloc_state *s) +void alloc_state_free_and_null(struct alloc_state **s_) { + struct alloc_state *s = *s_; + + if (!s) + return; + while (s->slab_nr > 0) { s->slab_nr--; free(s->slabs[s->slab_nr]); } FREE_AND_NULL(s->slabs); + FREE_AND_NULL(*s_); } static inline void *alloc_node(struct alloc_state *s, size_t node_size) -- cgit v1.2.3