diff options
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/mm/slub.c b/mm/slub.c index 80da3a40b74d..c80e6699357c 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -249,7 +249,18 @@ static inline void *freelist_ptr(const struct kmem_cache *s, void *ptr, unsigned long ptr_addr) { #ifdef CONFIG_SLAB_FREELIST_HARDENED - return (void *)((unsigned long)ptr ^ s->random ^ ptr_addr); + /* + * When CONFIG_KASAN_SW_TAGS is enabled, ptr_addr might be tagged. + * Normally, this doesn't cause any issues, as both set_freepointer() + * and get_freepointer() are called with a pointer with the same tag. + * However, there are some issues with CONFIG_SLUB_DEBUG code. For + * example, when __free_slub() iterates over objects in a cache, it + * passes untagged pointers to check_object(). check_object() in turns + * calls get_freepointer() with an untagged pointer, which causes the + * freepointer to be restored incorrectly. + */ + return (void *)((unsigned long)ptr ^ s->random ^ + (unsigned long)kasan_reset_tag((void *)ptr_addr)); #else return ptr; #endif |