Commit f16de0bc authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Linus Torvalds
Browse files

kasan: test: avoid corrupting memory in kasan_rcu_uaf 

kasan_rcu_uaf() writes to freed memory via kasan_rcu_reclaim(), which is
only safe with the GENERIC mode (as it uses quarantine).  For other modes,
this test corrupts kernel memory, which might result in a crash.

Turn the write into a read.

Link: https://lkml.kernel.org/r/b6f2c3bf712d2457c783fa59498225b66a634f62.1628779805.git.andreyknvl@gmail.com


Signed-off-by: default avatarAndrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: default avatarMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 756e5a47

lib/test_kasan_module.c

+1 −1
Original line number Diff line number Diff line
@@ -71,7 +71,7 @@ static noinline void __init kasan_rcu_reclaim(struct rcu_head *rp) 
						struct kasan_rcu_info, rcu);



	kfree(fp);

	fp->i = 1;

	((volatile struct kasan_rcu_info *)fp)->i;

}



static noinline void __init kasan_rcu_uaf(void)