4.16-stable review patch. If anyone has any objections, please let me know.
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From: Andrey Konovalov andreyknvl@google.com
[ Upstream commit 91c93ed07f04f5b32a30321d522d8ca9504745bf ]
When an invalid-free is triggered by one of the KASAN tests, the object doesn't actually get freed. This later leads to a BUG failure in kmem_cache_destroy that checks that there are no allocated objects in the cache that is being destroyed.
Fix this by calling kmem_cache_free with the proper object address after the call that triggers invalid-free.
Link: http://lkml.kernel.org/r/286eaefc0a6c3fa9b83b87e7d6dc0fbb5b5c9926.1519924383... Signed-off-by: Andrey Konovalov andreyknvl@google.com Acked-by: Andrey Ryabinin aryabinin@virtuozzo.com Cc: Alexander Potapenko glider@google.com Cc: Dmitry Vyukov dvyukov@google.com Cc: Geert Uytterhoeven geert@linux-m68k.org Cc: Nick Terrell terrelln@fb.com Cc: Chris Mason clm@fb.com Cc: Yury Norov ynorov@caviumnetworks.com Cc: Al Viro viro@zeniv.linux.org.uk Cc: "Luis R . Rodriguez" mcgrof@kernel.org Cc: Palmer Dabbelt palmer@dabbelt.com Cc: "Paul E . McKenney" paulmck@linux.vnet.ibm.com Cc: Jeff Layton jlayton@redhat.com Cc: "Jason A . Donenfeld" Jason@zx2c4.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 Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- lib/test_kasan.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -567,7 +567,15 @@ static noinline void __init kmem_cache_i return; }
+ /* Trigger invalid free, the object doesn't get freed */ kmem_cache_free(cache, p + 1); + + /* + * Properly free the object to prevent the "Objects remaining in + * test_cache on __kmem_cache_shutdown" BUG failure. + */ + kmem_cache_free(cache, p); + kmem_cache_destroy(cache); }