From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:51586 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932314AbcFCPnb (ORCPT ); Fri, 3 Jun 2016 11:43:31 -0400 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 7E527AC3D for ; Fri, 3 Jun 2016 15:43:30 +0000 (UTC) From: David Sterba To: stable@vger.kernel.org Subject: [PATCH 20/21] btrfs: scrub: Set bbio to NULL before calling btrfs_map_block Date: Fri, 3 Jun 2016 17:42:51 +0200 Message-Id: <1464968571-7088-1-git-send-email-dsterba@suse.com> In-Reply-To: <20160603154006.GP29147@suse.cz> References: <20160603154006.GP29147@suse.cz> Sender: stable-owner@vger.kernel.org List-ID: From: Zhao Lei commit f1fee6534dcfbf468a159789aa202db2bce8c200 upstream. We usually call btrfs_put_bbio() when btrfs_map_block() failed, btrfs_put_bbio() works right whether bbio is a valid value, or NULL. But there is a exception, in some case, btrfs_map_block() will return fail without touching *bbio(keeping its original value), and if bbio was not initialized yet, invalid memory accessing will happened. Above case is in scrub_missing_raid56_pages(), and similar case in scrub_raid56_parity(). Signed-off-by: Zhao Lei Signed-off-by: David Sterba --- fs/btrfs/scrub.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index ee046f6fffe0..2b7986e9df03 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -2179,7 +2179,7 @@ static void scrub_missing_raid56_pages(struct scrub_block *sblock) struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; u64 length = sblock->page_count * PAGE_SIZE; u64 logical = sblock->pagev[0]->logical; - struct btrfs_bio *bbio; + struct btrfs_bio *bbio = NULL; struct bio *bio; struct btrfs_raid_bio *rbio; int ret; @@ -2980,6 +2980,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx, extent_len); mapped_length = extent_len; + bbio = NULL; ret = btrfs_map_block(fs_info, READ, extent_logical, &mapped_length, &bbio, 0); if (!ret) { -- 2.7.1