diff --git a/mm/slub.c b/mm/slub.c index b762450fc9f0..6972c27ae394 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -679,6 +679,20 @@ static void slab_fix(struct kmem_cache *s, char *fmt, ...) va_end(args); } +static bool freelist_corrupted(struct kmem_cache *s, struct page *page, + void *freelist, void *nextfree) +{ + if ((s->flags & SLAB_CONSISTENCY_CHECKS) && + !check_valid_pointer(s, page, nextfree)) { + object_err(s, page, freelist, "Freechain corrupt"); + freelist = NULL; + slab_fix(s, "Isolate corrupted freechain"); + return true; + } + + return false; +} + static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p) { unsigned int off; /* Offset of last byte */ @@ -1410,6 +1424,11 @@ static inline void inc_slabs_node(struct kmem_cache *s, int node, static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects) {} +static bool freelist_corrupted(struct kmem_cache *s, struct page *page, + void *freelist, void *nextfree) +{ + return false; +} #endif /* CONFIG_SLUB_DEBUG */ /* @@ -2093,6 +2112,14 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page, void *prior; unsigned long counters; + /* + * If 'nextfree' is invalid, it is possible that the object at + * 'freelist' is already corrupted. So isolate all objects + * starting at 'freelist'. + */ + if (freelist_corrupted(s, page, freelist, nextfree)) + break; + do { prior = page->freelist; counters = page->counters;