From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:49812 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752867AbdJFI4V (ORCPT ); Fri, 6 Oct 2017 04:56:21 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Diego , Liu Bo , David Sterba , Sasha Levin Subject: [PATCH 4.9 068/104] Btrfs: fix potential use-after-free for cloned bio Date: Fri, 6 Oct 2017 10:51:46 +0200 Message-Id: <20171006083850.887266782@linuxfoundation.org> In-Reply-To: <20171006083840.743659740@linuxfoundation.org> References: <20171006083840.743659740@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Liu Bo [ Upstream commit a967efb30b3afa3d858edd6a17f544f9e9e46eea ] KASAN reports that there is a use-after-free case of bio in btrfs_map_bio. If we need to submit IOs to several disks at a time, the original bio would get cloned and mapped to the destination disk, but we really should use the original bio instead of a cloned bio to do the sanity check because cloned bios are likely to be freed by its endio. Reported-by: Diego Signed-off-by: Liu Bo Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/volumes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6226,7 +6226,7 @@ int btrfs_map_bio(struct btrfs_root *roo for (dev_nr = 0; dev_nr < total_devs; dev_nr++) { dev = bbio->stripes[dev_nr].dev; if (!dev || !dev->bdev || - (bio_op(bio) == REQ_OP_WRITE && !dev->writeable)) { + (bio_op(first_bio) == REQ_OP_WRITE && !dev->writeable)) { bbio_error(bbio, first_bio, logical); continue; }