From 91c93ed07f04f5b32a30321d522d8ca9504745bf Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Tue, 10 Apr 2018 16:30:35 -0700 Subject: [PATCH] kasan: fix invalid-free test crashing the kernel 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.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Acked-by: Andrey Ryabinin Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Geert Uytterhoeven Cc: Nick Terrell Cc: Chris Mason Cc: Yury Norov Cc: Al Viro Cc: "Luis R . Rodriguez" Cc: Palmer Dabbelt Cc: "Paul E . McKenney" Cc: Jeff Layton Cc: "Jason A . Donenfeld" Cc: Kostya Serebryany Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/test_kasan.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/lib/test_kasan.c b/lib/test_kasan.c index 98854a64b014..ec657105edbf 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -567,7 +567,15 @@ static noinline void __init kmem_cache_invalid_free(void) 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); } -- 2.30.2