INFO: task syz-executor.4:28574 blocked for more than 143 seconds. Not tainted 5.13.0-rc2-next-20210518-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:27728 pid:28574 ppid: 8487 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:4688 [inline] __schedule+0xb38/0x58c0 kernel/sched/core.c:5945 schedule+0xcf/0x270 kernel/sched/core.c:6024 rwsem_down_write_slowpath+0x7dc/0x1200 kernel/locking/rwsem.c:1106 __down_write_common kernel/locking/rwsem.c:1261 [inline] __down_write_common kernel/locking/rwsem.c:1258 [inline] __down_write kernel/locking/rwsem.c:1270 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1407 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1949 raw_release+0x58/0x8a0 net/can/raw.c:354 __sock_release+0xcd/0x280 net/socket.c:599 sock_close+0x18/0x20 net/socket.c:1258 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xbfc/0x2a70 kernel/exit.c:826 do_group_exit+0x125/0x310 kernel/exit.c:923 get_signal+0x47f/0x2150 kernel/signal.c:2856 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:789 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x16e/0x280 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301 do_syscall_64+0x3e/0xb0 arch/x86/entry/common.c:57 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665d9 RSP: 002b:00007fb0dbc86188 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: 0000000000000004 RBX: 000000000056c038 RCX: 00000000004665d9 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffdae73adef R14: 00007fb0dbc86300 R15: 0000000000022000 Showing all locks held in the system: 2 locks held by kworker/u4:1/25: 1 lock held by khungtaskd/1627: #0: ffffffff8c17afe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6333 1 lock held by in:imklog/8148: #0: ffff888016bd4d70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 3 locks held by kworker/u4:10/14235: #0: ffff888016193138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888016193138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888016193138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888016193138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888016193138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888016193138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246 #1: ffffc9000fc1fda8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250 #2: ffffffff8d897750 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb10 net/core/net_namespace.c:557 2 locks held by syz-executor.4/28574: #0: ffff8880367e91d0 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:774 [inline] #0: ffff8880367e91d0 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:598 #1: ffffffff8d897750 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1949 1 lock held by syz-executor.1/28738: #0: ffffffff8d897750 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2f5/0x760 net/core/net_namespace.c:470 1 lock held by syz-executor.4/28740: #0: ffffffff8d897750 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2f5/0x760 net/core/net_namespace.c:470 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1627 Comm: khungtaskd Not tainted 5.13.0-rc2-next-20210518-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x13e/0x1d6 lib/dump_stack.c:129 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:254 [inline] watchdog+0xd3b/0xf50 kernel/hung_task.c:339 kthread+0x3b1/0x4a0 kernel/kthread.c:313 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: 25 Comm: kworker/u4:1 Not tainted 5.13.0-rc2-next-20210518-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_preemption_disabled+0xa/0x150 lib/smp_processor_id.c:13 Code: 31 ff 89 de 0f 1f 44 00 00 85 db 75 ae 0f 1f 44 00 00 41 bc 01 00 00 00 e8 e3 a2 b1 fa eb 9f cc 41 56 41 55 49 89 f5 41 54 55 <48> 89 fd 53 0f 1f 44 00 00 65 44 8b 25 cd 26 e4 76 65 8b 1d 1e 81 RSP: 0018:ffffc90000dffc50 EFLAGS: 00000283 RAX: 0000000000000000 RBX: ffff88802e0f9950 RCX: 0000000000000000 RDX: ffff888012445580 RSI: ffffffff89e31be0 RDI: ffffffff89e31c20 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff88bcbe8d R11: 0000000000000000 R12: ffffc90000dffda8 R13: ffffffff89e31be0 R14: dffffc0000000000 R15: 000000000000032a FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7670080000 CR3: 00000000133e5000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:339 [inline] rcu_is_watching+0xe/0xc0 kernel/rcu/tree.c:1160 rcu_read_unlock include/linux/rcupdate.h:716 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x73c/0xe50 net/batman-adv/network-coding.c:715 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294