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authorAndrey Ryabinin <aryabinin@virtuozzo.com>2016-06-24 14:49:34 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-06-24 17:23:52 -0700
commit9b75a867cc9ddbafcaf35029358ac500f2635ff3 (patch)
treecf3cb90c4ee9e12a42d89881c3aa12d8bb0ba33b /mm/mempool.c
parenta6921c2974a09bfe8d039980c0b14a305644930b (diff)
downloadlinux-9b75a867cc9ddbafcaf35029358ac500f2635ff3.tar.gz
mm: mempool: kasan: don't poot mempool objects in quarantine
Currently we may put reserved by mempool elements into quarantine via kasan_kfree(). This is totally wrong since quarantine may really free these objects. So when mempool will try to use such element, use-after-free will happen. Or mempool may decide that it no longer need that element and double-free it. So don't put object into quarantine in kasan_kfree(), just poison it. Rename kasan_kfree() to kasan_poison_kfree() to respect that. Also, we shouldn't use kasan_slab_alloc()/kasan_krealloc() in kasan_unpoison_element() because those functions may update allocation stacktrace. This would be wrong for the most of the remove_element call sites. (The only call site where we may want to update alloc stacktrace is in mempool_alloc(). Kmemleak solves this by calling kmemleak_update_trace(), so we could make something like that too. But this is out of scope of this patch). Fixes: 55834c59098d ("mm: kasan: initial memory quarantine implementation") Link: http://lkml.kernel.org/r/575977C3.1010905@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reported-by: Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com> Acked-by: Alexander Potapenko <glider@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Kostya Serebryany <kcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mempool.c')
-rw-r--r--mm/mempool.c12
1 files changed, 4 insertions, 8 deletions
diff --git a/mm/mempool.c b/mm/mempool.c
index 9e075f829d0d..8f65464da5de 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -104,20 +104,16 @@ static inline void poison_element(mempool_t *pool, void *element)
static void kasan_poison_element(mempool_t *pool, void *element)
{
- if (pool->alloc == mempool_alloc_slab)
- kasan_poison_slab_free(pool->pool_data, element);
- if (pool->alloc == mempool_kmalloc)
- kasan_kfree(element);
+ if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc)
+ kasan_poison_kfree(element);
if (pool->alloc == mempool_alloc_pages)
kasan_free_pages(element, (unsigned long)pool->pool_data);
}
static void kasan_unpoison_element(mempool_t *pool, void *element, gfp_t flags)
{
- if (pool->alloc == mempool_alloc_slab)
- kasan_slab_alloc(pool->pool_data, element, flags);
- if (pool->alloc == mempool_kmalloc)
- kasan_krealloc(element, (size_t)pool->pool_data, flags);
+ if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc)
+ kasan_unpoison_slab(element);
if (pool->alloc == mempool_alloc_pages)
kasan_alloc_pages(element, (unsigned long)pool->pool_data);
}