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authorAndrey Konovalov <andreyknvl@google.com>2019-02-20 22:20:28 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-02-21 09:01:00 -0800
commit51dedad06b5f6c3eea7ec1069631b1ef7796912a (patch)
treef98818f9d27bb7bcc606d6a610291d12fdeda720 /mm
parent219667c23c68eb3dbc0d5662b9246f28477fe529 (diff)
downloadlinux-51dedad06b5f6c3eea7ec1069631b1ef7796912a.tar.bz2
kasan, slab: make freelist stored without tags
Similarly to "kasan, slub: move kasan_poison_slab hook before page_address", move kasan_poison_slab() before alloc_slabmgmt(), which calls page_address(), to make page_address() return value to be non-tagged. This, combined with calling kasan_reset_tag() for off-slab slab management object, leads to freelist being stored non-tagged. Link: http://lkml.kernel.org/r/dfb53b44a4d00de3879a05a9f04c1f55e584f7a1.1550602886.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Qian Cai <cai@lca.pw> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgeniy Stepanov <eugenis@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/slab.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/mm/slab.c b/mm/slab.c
index c84458281a88..4ad95fcb1686 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2359,7 +2359,7 @@ static void *alloc_slabmgmt(struct kmem_cache *cachep,
void *freelist;
void *addr = page_address(page);
- page->s_mem = kasan_reset_tag(addr) + colour_off;
+ page->s_mem = addr + colour_off;
page->active = 0;
if (OBJFREELIST_SLAB(cachep))
@@ -2368,6 +2368,7 @@ static void *alloc_slabmgmt(struct kmem_cache *cachep,
/* Slab management obj is off-slab. */
freelist = kmem_cache_alloc_node(cachep->freelist_cache,
local_flags, nodeid);
+ freelist = kasan_reset_tag(freelist);
if (!freelist)
return NULL;
} else {
@@ -2681,6 +2682,13 @@ static struct page *cache_grow_begin(struct kmem_cache *cachep,
offset *= cachep->colour_off;
+ /*
+ * Call kasan_poison_slab() before calling alloc_slabmgmt(), so
+ * page_address() in the latter returns a non-tagged pointer,
+ * as it should be for slab pages.
+ */
+ kasan_poison_slab(page);
+
/* Get slab management. */
freelist = alloc_slabmgmt(cachep, page, offset,
local_flags & ~GFP_CONSTRAINT_MASK, page_node);
@@ -2689,7 +2697,6 @@ static struct page *cache_grow_begin(struct kmem_cache *cachep,
slab_map_pages(cachep, page, freelist);
- kasan_poison_slab(page);
cache_init_objs(cachep, page);
if (gfpflags_allow_blocking(local_flags))