====================================================== WARNING: possible circular locking dependency detected 4.19.195-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/32531 is trying to acquire lock: 00000000a12b0141 (pernet_ops_rwsem){++++}, at: unregister_netdevice_notifier+0x7b/0x330 net/core/dev.c:1708 but task is already holding lock: 00000000b7e04e1b (&sb->s_type->i_mutex_key#13){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] 00000000b7e04e1b (&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.4/32531: #0: 00000000b7e04e1b (&sb->s_type->i_mutex_key#13){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] #0: 00000000b7e04e1b (&sb->s_type->i_mutex_key#13){+.+.}, at: __sock_release+0x86/0x2a0 net/socket.c:578 stack backtrace: CPU: 0 PID: 32531 Comm: syz-executor.4 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:00007ffe5de16ae0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00000000004193eb RDX: 0000000000570c30 RSI: ffffffff8167a83a RDI: 0000000000000004 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b30d23bf0 R10: 00000000000001ec R11: 0000000000000293 R12: 0000000000098b60 R13: 00000000000003e8 R14: 000000000056bf80 R15: 0000000000098b32 caif:caif_disconnect_client(): nothing to disconnect audit: type=1800 audit(1625042253.645:21743): pid=32638 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.5" name="bus" dev="sda1" ino=15456 res=0 caif:caif_disconnect_client(): nothing to disconnect audit: type=1800 audit(1625042253.825:21744): pid=32638 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.5" name="bus" dev="sda1" ino=15439 res=0 caif:caif_disconnect_client(): nothing to disconnect audit: type=1800 audit(1625042254.105:21745): pid=32682 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.5" name="bus" dev="sda1" ino=15456 res=0 audit: type=1800 audit(1625042254.105:21746): pid=32684 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.0" name="bus" dev="sda1" ino=15469 res=0 caif:caif_disconnect_client(): nothing to disconnect audit: type=1800 audit(1625042254.475:21747): pid=32704 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.0" name="bus" dev="sda1" ino=15469 res=0 caif:caif_disconnect_client(): nothing to disconnect audit: type=1800 audit(1625042254.595:21748): pid=32708 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.5" name="bus" dev="sda1" ino=15456 res=0 caif:caif_disconnect_client(): nothing to disconnect audit: type=1800 audit(1625042254.715:21749): pid=32707 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.4" name="bus" dev="sda1" ino=15470 res=0 audit: type=1800 audit(1625042254.725:21750): pid=32710 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.2" name="bus" dev="sda1" ino=15444 res=0 caif:caif_disconnect_client(): nothing to disconnect audit: type=1800 audit(1625042254.795:21751): pid=32718 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.0" name="bus" dev="sda1" ino=15469 res=0 caif:caif_disconnect_client(): nothing to disconnect nla_parse: 8 callbacks suppressed netlink: 8 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.0'. IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 netlink: 244 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 244 bytes leftover after parsing attributes in process `syz-executor.5'. IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 batman_adv: batadv0: Interface deactivated: batadv_slave_0 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 batman_adv: batadv0: Removing interface: batadv_slave_0 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 batman_adv: batadv0: Interface deactivated: batadv_slave_1 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 batman_adv: batadv0: Removing interface: batadv_slave_1 netlink: 244 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 244 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 244 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 244 bytes leftover after parsing attributes in process `syz-executor.2'. IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 nla_parse: 4 callbacks suppressed netlink: 244 bytes leftover after parsing attributes in process `syz-executor.1'. IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 netlink: 244 bytes leftover after parsing attributes in process `syz-executor.0'.