linux-kernel - [PATCH 08/13] f2fs: fix to avoid panic in do_recover

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: <20190415072842.2438-8-yuchao0@huawei.com>
Date:   Mon, 15 Apr 2019 15:28:37 +0800
From:   Chao Yu <yuchao0@...wei.com>
To:     <jaegeuk@...nel.org>
CC:     <linux-f2fs-devel@...ts.sourceforge.net>,
        <linux-kernel@...r.kernel.org>, <chao@...nel.org>,
        Chao Yu <yuchao0@...wei.com>
Subject: [PATCH 08/13] f2fs: fix to avoid panic in do_recover_data()

As Jungyeon reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=203227

- Overview
When mounting the attached crafted image, following errors are reported.
Additionally, it hangs on sync after trying to mount it.

The image is intentionally fuzzed from a normal f2fs image for testing.
Compile options for F2FS are as follows.
CONFIG_F2FS_FS=y
CONFIG_F2FS_STAT_FS=y
CONFIG_F2FS_FS_XATTR=y
CONFIG_F2FS_FS_POSIX_ACL=y
CONFIG_F2FS_CHECK_FS=y

- Reproduces
mkdir test
mount -t f2fs tmp.img test
sync

- Messages
 kernel BUG at fs/f2fs/recovery.c:549!
 RIP: 0010:recover_data+0x167a/0x1780
 Call Trace:
  f2fs_recover_fsync_data+0x613/0x710
  f2fs_fill_super+0x1043/0x1aa0
  mount_bdev+0x16d/0x1a0
  mount_fs+0x4a/0x170
  vfs_kern_mount+0x5d/0x100
  do_mount+0x200/0xcf0
  ksys_mount+0x79/0xc0
  __x64_sys_mount+0x1c/0x20
  do_syscall_64+0x43/0xf0
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

During recovery, if ofs_of_node is inconsistent in between recovered
node page and original checkpointed node page, let's just fail recovery
instead of making kernel panic.

Signed-off-by: Chao Yu <yuchao0@...wei.com>
---
 fs/f2fs/recovery.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index 79f5812c5e1f..e04f82b3f4fc 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -551,7 +551,15 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
 		goto err;
 
 	f2fs_bug_on(sbi, ni.ino != ino_of_node(page));
-	f2fs_bug_on(sbi, ofs_of_node(dn.node_page) != ofs_of_node(page));
+
+	if (ofs_of_node(dn.node_page) != ofs_of_node(page)) {
+		f2fs_msg(sbi->sb, KERN_WARNING,
+			"Inconsistent ofs_of_node, ino:%lu, ofs:%u, %u",
+			inode->i_ino, ofs_of_node(dn.node_page),
+			ofs_of_node(page));
+		err = -EFAULT;
+		goto err;
+	}
 
 	for (; start < end; start++, dn.ofs_in_node++) {
 		block_t src, dest;
-- 
2.18.0.rc1