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Add two checks for zend_mm_heap's integrity #13943

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Merged
merged 1 commit into from
Apr 23, 2024
Merged

Add two checks for zend_mm_heap's integrity #13943

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6 changes: 6 additions & 0 deletions Zend/zend_alloc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1065,6 +1065,9 @@ static void *zend_mm_alloc_pages(zend_mm_heap *heap, uint32_t pages_count ZEND_F

found:
if (steps > 2 && pages_count < 8) {
ZEND_MM_CHECK(chunk->next->prev == chunk, "zend_mm_heap corrupted");
ZEND_MM_CHECK(chunk->prev->next == chunk, "zend_mm_heap corrupted");

/* move chunk into the head of the linked-list */
chunk->prev->next = chunk->next;
chunk->next->prev = chunk->prev;
Expand Down Expand Up @@ -1116,6 +1119,9 @@ static zend_never_inline void *zend_mm_alloc_large(zend_mm_heap *heap, size_t si

static zend_always_inline void zend_mm_delete_chunk(zend_mm_heap *heap, zend_mm_chunk *chunk)
{
ZEND_MM_CHECK(chunk->next->prev == chunk, "zend_mm_heap corrupted");
ZEND_MM_CHECK(chunk->prev->next == chunk, "zend_mm_heap corrupted");

chunk->next->prev = chunk->prev;
chunk->prev->next = chunk->next;
heap->chunks_count--;
Expand Down