====================================================== WARNING: possible circular locking dependency detected 4.14.212-syzkaller #0 Not tainted ------------------------------------------------------ kworker/0:2/3426 is trying to acquire lock: (&sb->s_type->i_mutex_key#10){+.+.}, at: [] inode_lock include/linux/fs.h:719 [inline] (&sb->s_type->i_mutex_key#10){+.+.}, at: [] __generic_file_fsync+0x9e/0x190 fs/libfs.c:989 but task is already holding lock: ((&dio->complete_work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((&dio->complete_work)){+.+.}: process_one_work+0x736/0x14a0 kernel/workqueue.c:2092 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #1 ("dio/%s"sb->s_id){+.+.}: flush_workqueue+0xfa/0x1310 kernel/workqueue.c:2624 drain_workqueue+0x177/0x3e0 kernel/workqueue.c:2789 destroy_workqueue+0x71/0x710 kernel/workqueue.c:4102 sb_init_dio_done_wq+0x61/0x80 fs/direct-io.c:635 do_blockdev_direct_IO fs/direct-io.c:1286 [inline] __blockdev_direct_IO+0x3dea/0xdc60 fs/direct-io.c:1422 ext4_direct_IO_write fs/ext4/inode.c:3716 [inline] ext4_direct_IO+0x888/0x1b80 fs/ext4/inode.c:3857 generic_file_direct_write+0x1df/0x420 mm/filemap.c:2958 __generic_file_write_iter+0x2a2/0x590 mm/filemap.c:3137 ext4_file_write_iter+0x276/0xd20 fs/ext4/file.c:270 call_write_iter include/linux/fs.h:1778 [inline] aio_write+0x2ed/0x560 fs/aio.c:1553 io_submit_one fs/aio.c:1641 [inline] do_io_submit+0x847/0x1570 fs/aio.c:1709 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #0 (&sb->s_type->i_mutex_key#10){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 down_write+0x34/0x90 kernel/locking/rwsem.c:54 inode_lock include/linux/fs.h:719 [inline] __generic_file_fsync+0x9e/0x190 fs/libfs.c:989 ext4_sync_file+0x8ed/0x12c0 fs/ext4/fsync.c:118 vfs_fsync_range+0x103/0x260 fs/sync.c:196 generic_write_sync include/linux/fs.h:2682 [inline] dio_complete+0x561/0x8d0 fs/direct-io.c:330 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 other info that might help us debug this: Chain exists of: &sb->s_type->i_mutex_key#10 --> "dio/%s"sb->s_id --> (&dio->complete_work) Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((&dio->complete_work)); lock("dio/%s"sb->s_id); lock((&dio->complete_work)); lock(&sb->s_type->i_mutex_key#10); *** DEADLOCK *** 2 locks held by kworker/0:2/3426: #0: ("dio/%s"sb->s_id){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087 #1: ((&dio->complete_work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091 stack backtrace: CPU: 0 PID: 3426 Comm: kworker/0:2 Not tainted 4.14.212-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: dio/sda1 dio_aio_complete_work Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 down_write+0x34/0x90 kernel/locking/rwsem.c:54 inode_lock include/linux/fs.h:719 [inline] __generic_file_fsync+0x9e/0x190 fs/libfs.c:989 ext4_sync_file+0x8ed/0x12c0 fs/ext4/fsync.c:118 vfs_fsync_range+0x103/0x260 fs/sync.c:196 generic_write_sync include/linux/fs.h:2682 [inline] dio_complete+0x561/0x8d0 fs/direct-io.c:330 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 audit: type=1326 audit(1608398632.002:4): auid=0 uid=0 gid=0 ses=4 pid=10265 comm="syz-executor.0" exe="/root/syz-executor.0" sig=31 arch=c000003e syscall=228 compat=0 ip=0x460faa code=0x0 audit: type=1326 audit(1608398632.792:5): auid=0 uid=0 gid=0 ses=4 pid=10265 comm="syz-executor.0" exe="/root/syz-executor.0" sig=31 arch=c000003e syscall=228 compat=0 ip=0x460faa code=0x0 netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. overlayfs: filesystem on './file0' not supported as upperdir audit: type=1804 audit(1608398634.252:6): pid=10620 uid=0 auid=0 ses=4 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir504619072/syzkaller.c5EwTp/61/bus" dev="sda1" ino=15758 res=1 audit: type=1804 audit(1608398634.302:7): pid=10600 uid=0 auid=0 ses=4 op="invalid_pcr" cause="ToMToU" comm="syz-executor.5" name="/root/syzkaller-testdir504619072/syzkaller.c5EwTp/61/bus" dev="sda1" ino=15758 res=1 audit: type=1804 audit(1608398635.172:8): pid=10637 uid=0 auid=0 ses=4 op="invalid_pcr" cause="ToMToU" comm="syz-executor.5" name="/root/syzkaller-testdir504619072/syzkaller.c5EwTp/61/bus" dev="sda1" ino=15758 res=1 sock: process `syz-executor.2' is using obsolete getsockopt SO_BSDCOMPAT sctp: [Deprecated]: syz-executor.5 (pid 10953) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect audit: type=1107 audit(1608398639.142:9): pid=11144 uid=0 auid=0 ses=4 msg='»'