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) <ritesh.list@xxxxxxxxx> Signed-off-by: Artem Sadovnikov <ancowi69@xxxxxxxxx> Signed-off-by: Mikhail Ukhin <mish.uxin2012@xxxxxxxxx> --- 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
