====================================================== WARNING: possible circular locking dependency detected 4.19.195-syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:1/23 is trying to acquire lock: 000000007e561fba ((wq_completion)"events"){+.+.}, at: flush_workqueue+0xe8/0x13e0 kernel/workqueue.c:2658 but task is already holding lock: 0000000065c8a005 (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:520 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (pernet_ops_rwsem){++++}: unregister_netdevice_notifier+0x7b/0x330 net/core/dev.c:1708 bcm_release+0x94/0x700 net/can/bcm.c:1525 __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 -> #2 (&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 -> #1 ((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 -> #0 ((wq_completion)"events"){+.+.}: flush_workqueue+0x117/0x13e0 kernel/workqueue.c:2661 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 other info that might help us debug this: Chain exists of: (wq_completion)"events" --> &sb->s_type->i_mutex_key#13 --> pernet_ops_rwsem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(pernet_ops_rwsem); lock(&sb->s_type->i_mutex_key#13); lock(pernet_ops_rwsem); lock((wq_completion)"events"); *** DEADLOCK *** 3 locks held by kworker/u4:1/23: #0: 0000000085bb5516 ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000fe5b9172 (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 0000000065c8a005 (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:520 stack backtrace: CPU: 1 PID: 23 Comm: kworker/u4:1 Not tainted 4.19.195-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net 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 flush_workqueue+0x117/0x13e0 kernel/workqueue.c:2661 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 BTRFS error (device loop1): superblock checksum mismatch BTRFS error (device loop1): open_ctree failed BTRFS error (device loop1): superblock checksum mismatch BTRFS error (device loop1): open_ctree failed dccp_invalid_packet: P.type (REQUEST) not Data || [Data]Ack, while P.X == 0 new mount options do not match the existing superblock, will be ignored print_req_error: I/O error, dev loop1, sector 36028797018963960 NILFS (loop1): unable to read secondary superblock (blocksize = 1024) NILFS (loop1): couldn't find nilfs on the device print_req_error: I/O error, dev loop1, sector 36028797018963960 NILFS (loop1): unable to read secondary superblock (blocksize = 1024) NILFS (loop1): couldn't find nilfs on the device dccp_invalid_packet: P.type (REQUEST) not Data || [Data]Ack, while P.X == 0 new mount options do not match the existing superblock, will be ignored overlayfs: unrecognized mount option "wo kdir=./file1" or missing value batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 audit: type=1804 audit(1624800963.489:5): pid=10561 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir517805675/syzkaller.pozPUq/28/bus" dev="sda1" ino=14011 res=1 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 overlayfs: 'file0' not a directory overlayfs: unrecognized mount option "wo kdir=./file1" or missing value device bridge_slave_1 left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_0 left promiscuous mode ieee802154 phy0 wpan0: encryption failed: -22 ieee802154 phy1 wpan1: encryption failed: -22 bridge0: port 1(bridge_slave_0) entered disabled state device veth1_macvtap left promiscuous mode device veth0_macvtap left promiscuous mode device veth1_vlan left promiscuous mode overlayfs: unrecognized mount option "wo kdir=./file1" or missing value device veth0_vlan left promiscuous mode audit: type=1804 audit(1624800964.239:6): pid=10600 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir517805675/syzkaller.pozPUq/28/bus" dev="sda1" ino=14011 res=1 device hsr_slave_1 left promiscuous mode device hsr_slave_0 left promiscuous mode team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed bond0 (unregistering): Releasing backup interface bond_slave_1 bond0 (unregistering): Releasing backup interface bond_slave_0 bond0 (unregistering): Released all slaves IPVS: ftp: loaded support on port[0] = 21 chnl_net:caif_netlink_parms(): no params data found bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered disabled state device bridge_slave_0 entered promiscuous mode bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_1 entered promiscuous mode bond0: Enslaving bond_slave_0 as an active interface with an up link bond0: Enslaving bond_slave_1 as an active interface with an up link IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready team0: Port device team_slave_0 added IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready team0: Port device team_slave_1 added batman_adv: batadv0: Adding interface: batadv_slave_0 batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active batman_adv: batadv0: Adding interface: batadv_slave_1 batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready device hsr_slave_0 entered promiscuous mode device hsr_slave_1 entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_UP): bond0: link is not ready 8021q: adding VLAN 0 to HW filter on device bond0 IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready bridge0: port 1(bridge_slave_0) entered disabled state bridge0: port 2(bridge_slave_1) entered disabled state IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready 8021q: adding VLAN 0 to HW filter on device team0 IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready IPv6: ADDRCONF(NETDEV_UP): hsr0: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready IPv6: ADDRCONF(NETDEV_UP): vxcan0: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready 8021q: adding VLAN 0 to HW filter on device batadv0 IPv6: ADDRCONF(NETDEV_UP): veth0_virt_wifi: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_UP): veth0_vlan: link is not ready IPv6: ADDRCONF(NETDEV_UP): vlan0: link is not ready IPv6: ADDRCONF(NETDEV_UP): vlan1: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready