Messages in this thread Patch in this message |  | | From | "Matthew Wilcox (Oracle)" <> | | Subject | [PATCH] kasan: Fix tag for large allocations when using CONFIG_SLAB | | Date | Fri, 1 Oct 2021 03:41:05 +0100 |
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If an object is allocated on a tail page of a multi-page slab, kasan will get the wrong tag because page->s_mem is NULL for tail pages. I'm not quite sure what the user-visible effect of this might be.
Fixes: 7f94ffbc4c6a ("kasan: add hooks implementation for tag-based mode") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- mm/kasan/common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 2baf121fb8c5..41779ad109cd 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -298,7 +298,7 @@ static inline u8 assign_tag(struct kmem_cache *cache, /* For caches that either have a constructor or SLAB_TYPESAFE_BY_RCU: */ #ifdef CONFIG_SLAB /* For SLAB assign tags based on the object index in the freelist. */ - return (u8)obj_to_index(cache, virt_to_page(object), (void *)object); + return (u8)obj_to_index(cache, virt_to_head_page(object), (void *)object); #else /* * For SLUB assign a random tag during slab creation, otherwise reuse -- 2.32.0
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