INFO: task kworker/u4:5:235 blocked for more than 143 seconds. Not tainted 5.11.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:24048 pid: 235 ppid: 2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:4324 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5075 schedule+0xcf/0x270 kernel/sched/core.c:5154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5213 __mutex_lock_common kernel/locking/mutex.c:1023 [inline] __mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1093 cfg802154_pernet_exit+0x13/0xd0 net/ieee802154/core.c:324 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:175 cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:595 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 INFO: task syz-executor.3:18495 blocked for more than 143 seconds. Not tainted 5.11.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:28592 pid:18495 ppid: 8421 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4324 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5075 schedule+0xcf/0x270 kernel/sched/core.c:5154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5213 __mutex_lock_common kernel/locking/mutex.c:1023 [inline] __mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1093 rtnl_lock net/core/rtnetlink.c:72 [inline] rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5550 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 __sys_sendto+0x21c/0x320 net/socket.c:1975 __do_sys_sendto net/socket.c:1987 [inline] __se_sys_sendto net/socket.c:1983 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:1983 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x41938c RSP: 002b:00007f918ee8e020 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f918ee8e110 RCX: 000000000041938c RDX: 0000000000000020 RSI: 00007f918ee8e160 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007f918ee8e074 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 00007f918ee8e0c8 R13: 00007f918ee8e160 R14: 0000000000000004 R15: 0000000000000000 INFO: task syz-executor.2:18469 blocked for more than 144 seconds. Not tainted 5.11.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:28400 pid:18469 ppid: 8419 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4324 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5075 schedule+0xcf/0x270 kernel/sched/core.c:5154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5213 __mutex_lock_common kernel/locking/mutex.c:1023 [inline] __mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1093 do_ip_setsockopt net/ipv4/ip_sockglue.c:944 [inline] ip_setsockopt+0x1c8/0x3a00 net/ipv4/ip_sockglue.c:1423 udp_setsockopt+0x76/0xc0 net/ipv4/udp.c:2719 __sys_setsockopt+0x2db/0x610 net/socket.c:2115 __do_sys_setsockopt net/socket.c:2126 [inline] __se_sys_setsockopt net/socket.c:2123 [inline] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2123 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x465ef9 RSP: 002b:00007f77d638d188 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465ef9 RDX: 0000000000000024 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00000000004bfa0c R08: 000000000000000c R09: 0000000000000000 R10: 0000000020000380 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007fff77abafef R14: 00007f77d638d300 R15: 0000000000022000 INFO: task syz-executor.4:18477 blocked for more than 144 seconds. Not tainted 5.11.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:28320 pid:18477 ppid: 8423 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4324 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5075 schedule+0xcf/0x270 kernel/sched/core.c:5154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5213 __mutex_lock_common kernel/locking/mutex.c:1023 [inline] __mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1093 __netlink_dump_start+0x16a/0x900 net/netlink/af_netlink.c:2345 netlink_dump_start include/linux/netlink.h:262 [inline] rtnetlink_rcv_msg+0x70e/0xad0 net/core/rtnetlink.c:5516 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2348 ___sys_sendmsg+0xf3/0x170 net/socket.c:2402 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2435 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x465ef9 RSP: 002b:00007f59fd2b2188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465ef9 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00000000004bfa0c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffcecc8251f R14: 00007f59fd2b2300 R15: 0000000000022000 INFO: task syz-executor.5:18485 blocked for more than 145 seconds. Not tainted 5.11.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack:28152 pid:18485 ppid: 8583 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4324 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5075 schedule+0xcf/0x270 kernel/sched/core.c:5154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5213 __mutex_lock_common kernel/locking/mutex.c:1023 [inline] __mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1093 ip6mr_sk_done+0xe9/0x370 net/ipv6/ip6mr.c:1583 rawv6_close+0x58/0x80 net/ipv6/raw.c:1198 inet_release+0x12e/0x280 net/ipv4/af_inet.c:431 inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:478 __sock_release+0xcd/0x280 net/socket.c:597 sock_close+0x18/0x20 net/socket.c:1256 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x41920b RSP: 002b:00007ffc6577cba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 000000000041920b RDX: 0000000008412bf6 RSI: 0000000008d38cf5 RDI: 0000000000000004 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b32437a1c R10: 000000000006cf6c R11: 0000000000000293 R12: 000000000056c9e0 R13: 000000000056c9e0 R14: 000000000056bf60 R15: 000000000022c308 INFO: task syz-executor.5:18487 blocked for more than 145 seconds. Not tainted 5.11.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack:27704 pid:18487 ppid: 8583 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4324 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5075 schedule+0xcf/0x270 kernel/sched/core.c:5154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5213 __mutex_lock_common kernel/locking/mutex.c:1023 [inline] __mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1093 rtnl_lock net/core/rtnetlink.c:72 [inline] rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5550 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2348 ___sys_sendmsg+0xf3/0x170 net/socket.c:2402 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2435 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x465ef9 RSP: 002b:00007f9bb5e3a188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465ef9 RDX: 0000000000000000 RSI: 00000000200002c0 RDI: 0000000000000008 RBP: 00000000004bfa0c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffc6577cb3f R14: 00007f9bb5e3a300 R15: 0000000000022000 Showing all locks held in the system: 4 locks held by kworker/u4:5/235: #0: ffff888011aa3138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888011aa3138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888011aa3138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888011aa3138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888011aa3138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888011aa3138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246 #1: ffffc90001a1fda8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250 #2: ffffffff8d6586d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb10 net/core/net_namespace.c:557 #3: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: cfg802154_pernet_exit+0x13/0xd0 net/ieee802154/core.c:324 1 lock held by khungtaskd/1650: #0: ffffffff8bf73be0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6327 1 lock held by in:imklog/8116: #0: ffff88801bc6c5f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:961 3 locks held by kworker/u4:1/1179: #0: ffff888142c35938 ((wq_completion)cfg80211){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888142c35938 ((wq_completion)cfg80211){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888142c35938 ((wq_completion)cfg80211){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888142c35938 ((wq_completion)cfg80211){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888142c35938 ((wq_completion)cfg80211){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888142c35938 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246 #1: ffffc9000332fda8 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250 #2: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: cfg80211_dfs_channels_update_work+0x91/0x5f0 net/wireless/mlme.c:842 3 locks held by kworker/1:4/8346: #0: ffff8881479eb538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881479eb538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8881479eb538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8881479eb538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8881479eb538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8881479eb538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246 #1: ffffc9000760fda8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250 #2: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4572 3 locks held by kworker/0:6/11919: #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246 #1: ffffc9000186fda8 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250 #2: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:250 3 locks held by kworker/0:8/13191: #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246 #1: ffffc90001dcfda8 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250 #2: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74 2 locks held by kworker/0:10/13192: #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246 #1: ffffc9000176fda8 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250 2 locks held by syz-executor.3/18468: #0: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5550 #1: ffffffff8bf7c7a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8bf7c7a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4fa/0x620 kernel/rcu/tree_exp.h:836 1 lock held by syz-executor.3/18495: #0: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5550 1 lock held by syz-executor.2/18469: #0: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: do_ip_setsockopt net/ipv4/ip_sockglue.c:944 [inline] #0: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: ip_setsockopt+0x1c8/0x3a00 net/ipv4/ip_sockglue.c:1423 1 lock held by syz-executor.4/18477: #0: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x16a/0x900 net/netlink/af_netlink.c:2345 2 locks held by syz-executor.5/18485: #0: ffff888085489c50 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:773 [inline] #0: ffff888085489c50 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:596 #1: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: ip6mr_sk_done+0xe9/0x370 net/ipv6/ip6mr.c:1583 1 lock held by syz-executor.5/18487: #0: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d66be28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5550 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1650 Comm: khungtaskd Not tainted 5.11.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0xfa/0x151 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd48/0xfb0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 13835 Comm: kworker/0:22 Not tainted 5.11.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events iterate_cleanup_work RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:202 [inline] RIP: 0010:atomic_try_cmpxchg_acquire include/asm-generic/atomic-instrumented.h:707 [inline] RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:82 [inline] RIP: 0010:do_raw_spin_lock+0x124/0x2b0 kernel/locking/spinlock_debug.c:113 Code: 00 00 48 89 ef be 04 00 00 00 c7 44 24 28 00 00 00 00 e8 3f bc 5c 00 be 04 00 00 00 48 8d 7c 24 28 e8 30 bc 5c 00 8b 44 24 28 01 00 00 00 89 44 24 04 f0 0f b1 55 00 0f 85 91 00 00 00 65 44 RSP: 0018:ffffc9000209fb40 EFLAGS: 00000297 RAX: 0000000000000000 RBX: 1ffff92000413f69 RCX: ffffffff81595920 RDX: fffff52000413f6d RSI: 0000000000000004 RDI: ffffc9000209fb68 RBP: ffffffff8bc6f580 R08: 0000000000000001 R09: 0000000000000003 R10: fffff52000413f6d R11: 0000000000000000 R12: ffffffff8bc6f588 R13: ffffffff8bc6f590 R14: 0000000000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fea711e7000 CR3: 0000000025c43000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: spin_lock include/linux/spinlock.h:354 [inline] nf_conntrack_lock net/netfilter/nf_conntrack_core.c:91 [inline] get_next_corpse net/netfilter/nf_conntrack_core.c:2200 [inline] nf_ct_iterate_cleanup+0x187/0x410 net/netfilter/nf_conntrack_core.c:2245 nf_ct_iterate_cleanup_net net/netfilter/nf_conntrack_core.c:2330 [inline] nf_ct_iterate_cleanup_net+0x118/0x170 net/netfilter/nf_conntrack_core.c:2315 iterate_cleanup_work+0x45/0x130 net/netfilter/nf_nat_masquerade.c:216 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294