Fuzzing reports a possible deadlock in jbd2_log_wait_commit.
The problem occurs in ext4_ind_migrate due to an incorrect order of
unlocking of the journal and write semaphores - the order of unlocking
must be the reverse of the order of locking.
Found by Linux Verification Center (linuxtesting.org) with syzkaller.
Reviewed-by: Ritesh Harjani (IBM) <[email protected]>
Signed-off-by: Artem Sadovnikov <[email protected]>
Signed-off-by: Mikhail Ukhin <[email protected]>
---
v2: New addresses have been added and Ritesh Harjani has been noted as a
reviewer.
fs/ext4/migrate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index b0ea646454ac..59290356aa5b 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -663,8 +663,8 @@ int ext4_ind_migrate(struct inode *inode)
if (unlikely(ret2 && !ret))
ret = ret2;
errout:
- ext4_journal_stop(handle);
up_write(&EXT4_I(inode)->i_data_sem);
+ ext4_journal_stop(handle);
out_unlock:
percpu_up_write(&sbi->s_writepages_rwsem);
return ret;
--
2.25.1