Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754545AbcDZXxz (ORCPT ); Tue, 26 Apr 2016 19:53:55 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:40419 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752607AbcDZXOQ (ORCPT ); Tue, 26 Apr 2016 19:14:16 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Eric Wheeler" , "Eric Wheeler" Date: Wed, 27 Apr 2016 01:02:21 +0200 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 080/217] bcache: fix cache_set_flush() NULL pointer dereference on OOM In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8426:ae4:c500:9cba:69ae:962d:6167 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 976 Lines: 32 3.16.35-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eric Wheeler commit f8b11260a445169989d01df75d35af0f56178f95 upstream. When bch_cache_set_alloc() fails to kzalloc the cache_set, the asyncronous closure handling tries to dereference a cache_set that hadn't yet been allocated inside of cache_set_flush() which is called by __cache_set_unregister() during cleanup. This appears to happen only during an OOM condition on bcache_register. Signed-off-by: Eric Wheeler Signed-off-by: Ben Hutchings --- drivers/md/bcache/super.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1385,6 +1385,9 @@ static void cache_set_flush(struct closu struct btree *b; unsigned i; + if (!c) + closure_return(cl); + bch_cache_accounting_destroy(&c->accounting); kobject_put(&c->internal);