f2fs: fix to avoid panic in do_recover_data()
authorChao Yu <yuchao0@huawei.com>
Mon, 15 Apr 2019 07:28:37 +0000 (15:28 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 15 Jun 2019 09:54:53 +0000 (11:54 +0200)
commit549f0930e57b4b77c85929ad63f0836d2ff373e6
treef5da3315f42015f2e2996cfc38eefd269078dc5a
parent4f2b302da410a5275b9a2bda4342c4b791b39bcd
f2fs: fix to avoid panic in do_recover_data()

[ Upstream commit 22d61e286e2d9097dae36f75ed48801056b77cac ]

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@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
fs/f2fs/recovery.c