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kasan, slab: make freelist stored without tags

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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>
This commit is contained in:
Andrey Konovalov 2019-02-20 22:20:28 -08:00 committed by Linus Torvalds
parent 219667c23c
commit 51dedad06b
1 changed files with 9 additions and 2 deletions
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11
mm/slab.c
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@ -2359,7 +2359,7 @@ static void *alloc_slabmgmt(struct kmem_cache *cachep,
void *freelist; void *freelist;
void *addr = page_address(page); void *addr = page_address(page);
page->s_mem = kasan_reset_tag(addr) + colour_off; page->s_mem = addr + colour_off;
page->active = 0; page->active = 0;
if (OBJFREELIST_SLAB(cachep)) if (OBJFREELIST_SLAB(cachep))
@ -2368,6 +2368,7 @@ static void *alloc_slabmgmt(struct kmem_cache *cachep,
/* Slab management obj is off-slab. */ /* Slab management obj is off-slab. */
freelist = kmem_cache_alloc_node(cachep->freelist_cache, freelist = kmem_cache_alloc_node(cachep->freelist_cache,
local_flags, nodeid); local_flags, nodeid);
freelist = kasan_reset_tag(freelist);
if (!freelist) if (!freelist)
return NULL; return NULL;
} else { } else {
@ -2681,6 +2682,13 @@ static struct page *cache_grow_begin(struct kmem_cache *cachep,
offset *= cachep->colour_off; 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. */ /* Get slab management. */
freelist = alloc_slabmgmt(cachep, page, offset, freelist = alloc_slabmgmt(cachep, page, offset,
local_flags & ~GFP_CONSTRAINT_MASK, page_node); 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); slab_map_pages(cachep, page, freelist);
kasan_poison_slab(page);
cache_init_objs(cachep, page); cache_init_objs(cachep, page);
if (gfpflags_allow_blocking(local_flags)) if (gfpflags_allow_blocking(local_flags))