audit: type=1804 audit(1624939829.547:25): pid=12862 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.3" name="/root/syzkaller-testdir066374387/syzkaller.a3o5yP/168/cgroup.controllers" dev="sda1" ino=14177 res=1 ====================================================== WARNING: possible circular locking dependency detected 4.19.195-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/12877 is trying to acquire lock: 00000000f7fb0bd4 (pernet_ops_rwsem){++++}, at: unregister_netdevice_notifier+0x7b/0x330 net/core/dev.c:1708 but task is already holding lock: 00000000f9450a41 (&sb->s_type->i_mutex_key#13){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] 00000000f9450a41 (&sb->s_type->i_mutex_key#13){+.+.}, at: __sock_release+0x86/0x2a0 net/socket.c:578 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&sb->s_type->i_mutex_key#13){+.+.}: 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 -> #2 ((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 -> #1 ((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 -> #0 (pernet_ops_rwsem){++++}: down_write+0x34/0x90 kernel/locking/rwsem.c:70 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 other info that might help us debug this: Chain exists of: pernet_ops_rwsem --> (delayed_fput_work).work --> &sb->s_type->i_mutex_key#13 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#13); lock((delayed_fput_work).work); lock(&sb->s_type->i_mutex_key#13); lock(pernet_ops_rwsem); *** DEADLOCK *** 1 lock held by syz-executor.1/12877: #0: 00000000f9450a41 (&sb->s_type->i_mutex_key#13){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] #0: 00000000f9450a41 (&sb->s_type->i_mutex_key#13){+.+.}, at: __sock_release+0x86/0x2a0 net/socket.c:578 stack backtrace: CPU: 0 PID: 12877 Comm: syz-executor.1 Not tainted 4.19.195-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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 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 RIP: 0033:0x4193eb Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 RSP: 002b:00007fff66ea6660 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00000000004193eb RDX: 00000000005702b8 RSI: ffffffff8167a83a RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b2f820d10 R10: 00000000000001ec R11: 0000000000000293 R12: 000000000003bd96 R13: 00000000000003e8 R14: 000000000056bf80 R15: 000000000003bd82 audit: type=1804 audit(1624939830.377:26): pid=12916 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.3" name="/root/syzkaller-testdir066374387/syzkaller.a3o5yP/169/cgroup.controllers" dev="sda1" ino=14188 res=1 overlayfs: unrecognized mount option "default" or missing value overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off. overlayfs: failed to resolve 'file0{]/͏H': -2 overlayfs: unrecognized mount option "default" or missing value overlayfs: filesystem on './bus' not supported as upperdir IPVS: sync thread started: state = BACKUP, mcast_ifn = vcan0, syncid = 0, id = 0 base_sock_release(000000001c63b0eb) sk=0000000097c02a82 base_sock_release(00000000937fce92) sk=0000000023537197 netlink: 'syz-executor.4': attribute type 10 has an invalid length. netlink: 'syz-executor.4': attribute type 10 has an invalid length. team0: Port device team_slave_1 removed netlink: 'syz-executor.4': attribute type 10 has an invalid length. IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready team0: Port device team_slave_1 added IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready base_sock_release(0000000093ec653e) sk=00000000dc57744e base_sock_release(00000000933a98cd) sk=000000009d95da18 base_sock_release(0000000006e03d07) sk=00000000fc1e69e2 base_sock_release(00000000325a294d) sk=000000002487ebe5 audit: type=1804 audit(1624939834.007:27): pid=13365 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir690942293/syzkaller.dwHYmt/198/cgroup.controllers" dev="sda1" ino=14219 res=1 base_sock_release(0000000092281c22) sk=000000006ae2f5a7 base_sock_release(0000000018837db2) sk=0000000023ba48d0 IPVS: ftp: loaded support on port[0] = 21 caif:caif_disconnect_client(): nothing to disconnect base_sock_release(00000000f367ff4b) sk=0000000056a1be00 caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect base_sock_release(00000000a0e7e448) sk=00000000a8a1bb62 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 caif:caif_disconnect_client(): nothing to disconnect IPVS: length: 81 != 24 base_sock_release(0000000055bf49e4) sk=000000001a01c12e base_sock_release(00000000bcd1414d) sk=00000000f67063e8 xt_CT: You must specify a L4 protocol and not use inversions on it x_tables: duplicate underflow at hook 1 x_tables: duplicate underflow at hook 1 IPVS: set_ctl: invalid protocol: 0 172.30.0.6:0 x_tables: duplicate underflow at hook 1 x_tables: duplicate underflow at hook 2