[PATCH 6.1 0607/1146] f2fs: fix to avoid accessing uninitialized spinlock

Greg Kroah-Hartman
2022-12-28T16:14:45Z

From: Chao Yu <chao@kernel.org>

[ Upstream commit cc249e4cba9a6002c9d9e1438daf8440a160bc9e ]

syzbot reports a kernel bug:

__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
assign_lock_key+0x22a/0x240 kernel/locking/lockdep.c:981
register_lock_class+0x287/0x9b0 kernel/locking/lockdep.c:1294
__lock_acquire+0xe4/0x1f60 kernel/locking/lockdep.c:4934
lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5668
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:350 [inline]
f2fs_save_errors fs/f2fs/super.c:3868 [inline]
f2fs_handle_error+0x29/0x230 fs/f2fs/super.c:3896
f2fs_iget+0x215/0x4bb0 fs/f2fs/inode.c:516
f2fs_fill_super+0x47d3/0x7b50 fs/f2fs/super.c:4222
mount_bdev+0x26c/0x3a0 fs/super.c:1401
legacy_get_tree+0xea/0x180 fs/fs_context.c:610
vfs_get_tree+0x88/0x270 fs/super.c:1531
do_new_mount+0x289/0xad0 fs/namespace.c:3040
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

F2FS-fs (loop1): Failed to read F2FS meta data inode

The root cause is if sbi->error_lock may be accessed before
its initialization, fix it.

Link: https://lore.kernel.org/linux-f2fs-devel/0000000000007edb6605ecbb6442@google.com/T/#u
Reported-by: syzbot+40642be9b7e0bb28e0df@syzkaller.appspotmail.com
Fixes: 95fa90c9e5a7 ("f2fs: support recording errors into superblock")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/f2fs/super.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 696f094c4505..67d51f527606 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -4188,6 +4188,9 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
if (err)
goto free_bio_info;

+ spin_lock_init(&sbi->error_lock);
+ memcpy(sbi->errors, raw_super->s_errors, MAX_F2FS_ERRORS);
+
init_f2fs_rwsem(&sbi->cp_rwsem);
init_f2fs_rwsem(&sbi->quota_sem);
init_waitqueue_head(&sbi->cp_wait);
@@ -4255,9 +4258,6 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
goto free_devices;
}

- spin_lock_init(&sbi->error_lock);
- memcpy(sbi->errors, raw_super->s_errors, MAX_F2FS_ERRORS);
-
sbi->total_valid_node_count =
le32_to_cpu(sbi->ckpt->valid_node_count);
percpu_counter_set(&sbi->total_valid_inode_count,
--
2.35.1