linux-kernel - [PATCH AUTOSEL 5.4 12/15] btrfs: handle chunk tree lookup error in btrfs_relocate_sys

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240329123445.3086536-12-sashal@kernel.org>
Date: Fri, 29 Mar 2024 08:34:35 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: David Sterba <dsterba@...e.com>,
	Josef Bacik <josef@...icpanda.com>,
	Anand Jain <anand.jain@...cle.com>,
	Sasha Levin <sashal@...nel.org>,
	clm@...com,
	linux-btrfs@...r.kernel.org
Subject: [PATCH AUTOSEL 5.4 12/15] btrfs: handle chunk tree lookup error in btrfs_relocate_sys_chunks()

From: David Sterba <dsterba@...e.com>

[ Upstream commit 7411055db5ce64f836aaffd422396af0075fdc99 ]

The unhandled case in btrfs_relocate_sys_chunks() loop is a corruption,
as it could be caused only by two impossible conditions:

- at first the search key is set up to look for a chunk tree item, with
  offset -1, this is an inexact search and the key->offset will contain
  the correct offset upon a successful search, a valid chunk tree item
  cannot have an offset -1

- after first successful search, the found_key corresponds to a chunk
  item, the offset is decremented by 1 before the next loop, it's
  impossible to find a chunk item there due to alignment and size
  constraints

Reviewed-by: Josef Bacik <josef@...icpanda.com>
Reviewed-by: Anand Jain <anand.jain@...cle.com>
Signed-off-by: David Sterba <dsterba@...e.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 fs/btrfs/volumes.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e11c8da9a5605..b5873df0aa93a 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3268,7 +3268,17 @@ static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info)
 			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
 			goto error;
 		}
-		BUG_ON(ret == 0); /* Corruption */
+		if (ret == 0) {
+			/*
+			 * On the first search we would find chunk tree with
+			 * offset -1, which is not possible. On subsequent
+			 * loops this would find an existing item on an invalid
+			 * offset (one less than the previous one, wrong
+			 * alignment and size).
+			 */
+			ret = -EUCLEAN;
+			goto error;
+		}
 
 		ret = btrfs_previous_item(chunk_root, path, key.objectid,
 					  key.type);
-- 
2.43.0