audit: type=1804 audit(1624948773.278:7): pid=10895 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.0" name="/root/syzkaller-testdir544402336/syzkaller.EMasc6/33/cgroup.controllers" dev="sda1" ino=14089 res=1 ====================================================== WARNING: possible circular locking dependency detected 4.19.195-syzkaller #0 Not tainted ------------------------------------------------------ kworker/1:1/33 is trying to acquire lock: 0000000004838c0b (&sb->s_type->i_mutex_key#13){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] 0000000004838c0b (&sb->s_type->i_mutex_key#13){+.+.}, at: __sock_release+0x86/0x2a0 net/socket.c:578 but task is already holding lock: 00000000819083b4 ((delayed_fput_work).work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 ((delayed_fput_work).work){+.+.}: worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 -> #2 ((wq_completion)"events"){+.+.}: flush_scheduled_work include/linux/workqueue.h:599 [inline] tipc_exit_net+0x38/0x60 net/tipc/core.c:100 ops_exit_list+0xa5/0x150 net/core/net_namespace.c:153 cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:553 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 -> #1 (pernet_ops_rwsem){++++}: unregister_netdevice_notifier+0x7b/0x330 net/core/dev.c:1708 raw_release+0x58/0x820 net/can/raw.c:358 __sock_release+0xcd/0x2a0 net/socket.c:579 sock_close+0x15/0x20 net/socket.c:1140 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&sb->s_type->i_mutex_key#13){+.+.}: down_write+0x34/0x90 kernel/locking/rwsem.c:70 inode_lock include/linux/fs.h:748 [inline] __sock_release+0x86/0x2a0 net/socket.c:578 sock_close+0x15/0x20 net/socket.c:1140 __fput+0x2ce/0x890 fs/file_table.c:278 delayed_fput+0x56/0x70 fs/file_table.c:304 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 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#13 --> (wq_completion)"events" --> (delayed_fput_work).work Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((delayed_fput_work).work); lock((wq_completion)"events"); lock((delayed_fput_work).work); lock(&sb->s_type->i_mutex_key#13); *** DEADLOCK *** 2 locks held by kworker/1:1/33: #0: 00000000b86bd5ad ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000819083b4 ((delayed_fput_work).work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 stack backtrace: CPU: 1 PID: 33 Comm: kworker/1:1 Not tainted 4.19.195-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events delayed_fput Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1222 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2420 [inline] __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3416 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 down_write+0x34/0x90 kernel/locking/rwsem.c:70 inode_lock include/linux/fs.h:748 [inline] __sock_release+0x86/0x2a0 net/socket.c:578 sock_close+0x15/0x20 net/socket.c:1140 __fput+0x2ce/0x890 fs/file_table.c:278 delayed_fput+0x56/0x70 fs/file_table.c:304 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 audit: type=1800 audit(1624948774.308:8): pid=10901 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed comm="syz-executor.3" name="bus" dev="sda1" ino=14022 res=0 can: request_module (can-proto-0) failed. EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue tmpfs: Bad value 'prefer:' for mount option 'mpol' tmpfs: Bad value 'prefer:' for mount option 'mpol' can: request_module (can-proto-0) failed. netlink: 3 bytes leftover after parsing attributes in process `syz-executor.2'. FAT-fs (loop3): bogus number of reserved sectors FAT-fs (loop3): Can't find a valid FAT filesystem IPVS: ftp: loaded support on port[0] = 21 kvm: vcpu 0: requested 128 ns lapic timer period limited to 200000 ns EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue befs: (loop3): No write support. Marking filesystem read-only befs: (loop3): invalid magic header befs: (loop3): No write support. Marking filesystem read-only audit: type=1804 audit(1624948776.278:9): pid=11091 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir471836454/syzkaller.Z56Etl/33/cgroup.controllers" dev="sda1" ino=14109 res=1 befs: (loop3): invalid magic header mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue overlayfs: at least 2 lowerdir are needed while upperdir nonexistent overlayfs: at least 2 lowerdir are needed while upperdir nonexistent IPVS: ftp: loaded support on port[0] = 21 audit: type=1804 audit(1624948779.359:10): pid=11292 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.4" name="/root/syzkaller-testdir028604668/syzkaller.DdqviF/32/cgroup.controllers" dev="sda1" ino=14131 res=1 block nbd3: Receive control failed (result -107) block nbd3: shutting down sockets Started in network mode Own node identity 9, cluster identity 4711 32-bit node address hash set to 9 IPVS: ftp: loaded support on port[0] = 21 Left network mode Started in network mode Own node identity 9, cluster identity 4711 32-bit node address hash set to 9 overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off. overlayfs: 'file0' not a directory overlayfs: filesystem on './bus' not supported as upperdir audit: type=1804 audit(1624948780.339:11): pid=11420 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.0" name="/root/syzkaller-testdir544402336/syzkaller.EMasc6/45/cgroup.controllers" dev="sda1" ino=14116 res=1 audit: type=1804 audit(1624948780.439:12): pid=11440 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir346469129/syzkaller.ZvF6Je/30/bus" dev="sda1" ino=14139 res=1 hid-generic 0000:0000:0000.0001: ignoring exceeding usage max hid-generic 0000:0000:0000.0001: hidraw0: HID v0.00 Device [syz1] on %z5 audit: type=1800 audit(1624948780.439:13): pid=11440 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.1" name="bus" dev="sda1" ino=14139 res=0 hid-generic 0000:0000:0000.0002: ignoring exceeding usage max hid-generic 0000:0000:0000.0002: hidraw0: HID v0.00 Device [syz1] on %z5 audit: type=1804 audit(1624948780.439:14): pid=11440 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir346469129/syzkaller.ZvF6Je/30/bus" dev="sda1" ino=14139 res=1 audit: type=1800 audit(1624948780.439:15): pid=11440 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.1" name="bus" dev="sda1" ino=14139 res=0 audit: type=1804 audit(1624948780.449:16): pid=11440 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir346469129/syzkaller.ZvF6Je/30/bus" dev="sda1" ino=14139 res=1 audit: type=1800 audit(1624948780.449:17): pid=11440 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.1" name="bus" dev="sda1" ino=14139 res=0 audit: type=1804 audit(1624948780.449:18): pid=11440 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir346469129/syzkaller.ZvF6Je/30/bus" dev="sda1" ino=14139 res=1 audit: type=1800 audit(1624948780.449:19): pid=11440 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.1" name="bus" dev="sda1" ino=14139 res=0 audit: type=1804 audit(1624948781.079:20): pid=11494 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.4" name="/root/syzkaller-testdir028604668/syzkaller.DdqviF/37/cgroup.controllers" dev="sda1" ino=14156 res=1 tc_dump_action: action bad kind tc_dump_action: action bad kind tc_dump_action: action bad kind audit: type=1804 audit(1624948781.779:21): pid=11535 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.4" name="/root/syzkaller-testdir028604668/syzkaller.DdqviF/38/cgroup.controllers" dev="sda1" ino=14133 res=1 tc_dump_action: action bad kind tc_dump_action: action bad kind tc_dump_action: action bad kind tc_dump_action: action bad kind sp0: Synchronizing with TNC tc_dump_action: action bad kind sp0: Synchronizing with TNC audit: type=1804 audit(1624948782.299:22): pid=11598 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.4" name="/root/syzkaller-testdir028604668/syzkaller.DdqviF/39/cgroup.controllers" dev="sda1" ino=14133 res=1 tc_dump_action: action bad kind tc_dump_action: action bad kind tc_dump_action: action bad kind tc_dump_action: action bad kind tc_dump_action: action bad kind tc_dump_action: action bad kind tc_dump_action: action bad kind tc_dump_action: action bad kind tc_dump_action: action bad kind FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1