[PATCH 4.14 27/81] f2fs: fix to clear dirty inode in error path of f2fs_iget()

Greg Kroah-Hartman
2019-06-13T16:29:08Z

[ Upstream commit 546d22f070d64a7b96f57c93333772085d3a5e6d ]

As Jungyeon reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=203217

- Overview
When mounting the attached crafted image and running program, I got this error.
Additionally, it hangs on sync after running the program.

The image is intentionally fuzzed from a normal f2fs image for testing and I enabled option CONFIG_F2FS_CHECK_FS on.

- Reproduces
cc poc_test_05.c
mkdir test
mount -t f2fs tmp.img test
sudo ./a.out
sync

- Messages
kernel BUG at fs/f2fs/inode.c:707!
RIP: 0010:f2fs_evict_inode+0x33f/0x3a0
Call Trace:
evict+0xba/0x180
f2fs_iget+0x598/0xdf0
f2fs_lookup+0x136/0x320
__lookup_slow+0x92/0x140
lookup_slow+0x30/0x50
walk_component+0x1c1/0x350
path_lookupat+0x62/0x200
filename_lookup+0xb3/0x1a0
do_readlinkat+0x56/0x110
__x64_sys_readlink+0x16/0x20
do_syscall_64+0x43/0xf0
entry_SYSCALL_64_after_hwframe+0x44/0xa9

During inode loading, __recover_inline_status() can recovery inode status
and set inode dirty, once we failed in following process, it will fail
the check in f2fs_evict_inode, result in trigger BUG_ON().

Let's clear dirty inode in error path of f2fs_iget() to avoid 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/inode.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 50818b519df8..e02ed16bc35c 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -397,6 +397,7 @@ make_now:
return inode;

bad_inode:
+ f2fs_inode_synced(inode);
iget_failed(inode);
trace_f2fs_iget_exit(inode, ret);
return ERR_PTR(ret);
--
2.20.1