====================================================== WARNING: possible circular locking dependency detected 4.19.167-syzkaller #0 Not tainted ------------------------------------------------------ kworker/0:2/3683 is trying to acquire lock: 00000000ae606a50 (&sb->s_type->i_mutex_key#10){++++}, at: inode_lock include/linux/fs.h:748 [inline] 00000000ae606a50 (&sb->s_type->i_mutex_key#10){++++}, at: __generic_file_fsync+0xb0/0x1f0 fs/libfs.c:989 but task is already holding lock: 00000000ca4b8b1c ((work_completion)(&dio->complete_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2130 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((work_completion)(&dio->complete_work)){+.+.}: worker_thread+0x64c/0x1130 kernel/workqueue.c:2298 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 -> #1 ((wq_completion)"dio/%s"sb->s_id){+.+.}: drain_workqueue+0x1a5/0x460 kernel/workqueue.c:2828 destroy_workqueue+0x75/0x790 kernel/workqueue.c:4179 __alloc_workqueue_key+0xb76/0xed0 kernel/workqueue.c:4156 sb_init_dio_done_wq+0x34/0x90 fs/direct-io.c:623 dio_set_defer_completion fs/direct-io.c:646 [inline] get_more_blocks fs/direct-io.c:724 [inline] do_direct_IO fs/direct-io.c:1002 [inline] do_blockdev_direct_IO fs/direct-io.c:1332 [inline] __blockdev_direct_IO+0x836b/0xeee6 fs/direct-io.c:1418 ext4_direct_IO_write fs/ext4/inode.c:3778 [inline] ext4_direct_IO+0xae4/0x1c50 fs/ext4/inode.c:3916 generic_file_direct_write+0x208/0x4a0 mm/filemap.c:3073 __generic_file_write_iter+0x2d0/0x610 mm/filemap.c:3252 ext4_file_write_iter+0x2fe/0xf20 fs/ext4/file.c:272 call_write_iter include/linux/fs.h:1821 [inline] aio_write+0x37f/0x5c0 fs/aio.c:1574 __io_submit_one fs/aio.c:1858 [inline] io_submit_one+0xecd/0x20c0 fs/aio.c:1909 __do_sys_io_submit fs/aio.c:1953 [inline] __se_sys_io_submit+0x11b/0x4a0 fs/aio.c:1924 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&sb->s_type->i_mutex_key#10){++++}: down_write+0x34/0x90 kernel/locking/rwsem.c:70 inode_lock include/linux/fs.h:748 [inline] __generic_file_fsync+0xb0/0x1f0 fs/libfs.c:989 ext4_sync_file+0xa35/0x1420 fs/ext4/fsync.c:118 vfs_fsync_range+0x13a/0x220 fs/sync.c:197 generic_write_sync include/linux/fs.h:2751 [inline] dio_complete+0x763/0xac0 fs/direct-io.c:329 process_one_work+0x864/0x1570 kernel/workqueue.c:2155 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 other info that might help us debug this: Chain exists of: &sb->s_type->i_mutex_key#10 --> (wq_completion)"dio/%s"sb->s_id --> (work_completion)(&dio->complete_work) Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((work_completion)(&dio->complete_work)); lock((wq_completion)"dio/%s"sb->s_id); lock((work_completion)(&dio->complete_work)); lock(&sb->s_type->i_mutex_key#10); *** DEADLOCK *** 2 locks held by kworker/0:2/3683: #0: 00000000a810eff9 ((wq_completion)"dio/%s"sb->s_id){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2126 #1: 00000000ca4b8b1c ((work_completion)(&dio->complete_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2130 stack backtrace: CPU: 0 PID: 3683 Comm: kworker/0:2 Not tainted 4.19.167-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:77 [inline] dump_stack+0x1fc/0x2fe lib/dump_stack.c:118 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1221 check_prev_add kernel/locking/lockdep.c:1865 [inline] check_prevs_add kernel/locking/lockdep.c:1978 [inline] validate_chain kernel/locking/lockdep.c:2419 [inline] __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3415 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3907 down_write+0x34/0x90 kernel/locking/rwsem.c:70 inode_lock include/linux/fs.h:748 [inline] __generic_file_fsync+0xb0/0x1f0 fs/libfs.c:989 ext4_sync_file+0xa35/0x1420 fs/ext4/fsync.c:118 vfs_fsync_range+0x13a/0x220 fs/sync.c:197 generic_write_sync include/linux/fs.h:2751 [inline] dio_complete+0x763/0xac0 fs/direct-io.c:329 process_one_work+0x864/0x1570 kernel/workqueue.c:2155 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'. libceph: mon0 [d::]:6789 socket closed (con state CONNECTING) netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'. IPVS: stopping master sync thread 8366 ... IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 2048, id = 0 IPVS: stopping master sync thread 8372 ... IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 2048, id = 0 IPVS: stopping master sync thread 8398 ... IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 2048, id = 0 IPVS: stopping master sync thread 8401 ... IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 2048, id = 0 IPVS: stopping master sync thread 8420 ... IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 2048, id = 0 IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 2048, id = 0 IPVS: stopping master sync thread 8423 ... IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 2048, id = 0 IPVS: stopping master sync thread 8442 ... IPVS: stopping master sync thread 8444 ... IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 2048, id = 0 BTRFS: device fsid f90cac8b-044b-4fa8-8bee-4b8d3da88dc2 devid 0 transid 7 /dev/loop3 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. libceph: mon0 [d::]:6789 socket closed (con state CONNECTING) netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. libceph: mon0 [d::]:6789 socket closed (con state CONNECTING) audit: type=1800 audit(1610484709.381:230): pid=8753 uid=0 auid=0 ses=4 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.5" name="file0" dev="sda1" ino=16382 res=0 audit: type=1800 audit(1610484709.421:231): pid=8753 uid=0 auid=0 ses=4 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.5" name="file0" dev="sda1" ino=16382 res=0