INFO: task syz-executor.0:23722 blocked for more than 143 seconds. Not tainted 5.7.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D25608 23722 7033 0x80004006 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x937/0x1ff0 kernel/sched/core.c:4083 rwsem_down_write_slowpath+0x90a/0xf90 kernel/locking/rwsem.c:1216 __sched_text_start+0x8/0x8 schedule+0xd0/0x2a0 kernel/sched/core.c:4158 rwsem_down_write_slowpath+0x706/0xf90 kernel/locking/rwsem.c:1235 rwsem_mark_wake+0x8d0/0x8d0 include/linux/compiler.h:199 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1776 lock_release+0x800/0x800 kernel/locking/lockdep.c:4689 __sock_release+0x280/0x280 net/socket.c:605 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1532 atomic64_try_cmpxchg include/asm-generic/atomic-instrumented.h:1504 [inline] atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:442 [inline] __down_write kernel/locking/rwsem.c:1387 [inline] down_write+0xb2/0x150 kernel/locking/rwsem.c:1532 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1532 __down_timeout+0x2d0/0x2d0 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1776 __sock_release+0x280/0x280 net/socket.c:605 raw_release+0x53/0x730 net/can/raw.c:354 fcntl_setlk+0xcc0/0xcc0 fs/locks.c:2542 __sock_release+0x280/0x280 net/socket.c:605 __sock_release+0xcd/0x280 net/socket.c:605 sock_close+0x18/0x20 net/socket.c:1283 __fput+0x33e/0x880 fs/file_table.c:280 task_work_run+0xf4/0x1b0 kernel/task_work.c:123 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xb34/0x2dd0 kernel/exit.c:796 find_held_lock+0x2d/0x110 kernel/locking/lockdep.c:4458 mm_update_next_owner+0x7a0/0x7a0 kernel/exit.c:375 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 do_group_exit+0x125/0x340 kernel/exit.c:894 get_signal+0x47b/0x24e0 kernel/signal.c:2739 find_held_lock+0x2d/0x110 kernel/locking/lockdep.c:4458 do_signal+0x81/0x2240 arch/x86/kernel/signal.c:784 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 rcu_read_lock_any_held.part.0+0x50/0x50 arch/x86/include/asm/paravirt.h:754 get_sigframe.isra.0+0x730/0x730 arch/x86/kernel/signal.c:268 rcu_read_unlock_sched include/linux/rcupdate.h:732 [inline] __fd_install+0x1e6/0x600 fs/file.c:613 __sys_socket+0x16d/0x200 net/socket.c:438 move_addr_to_kernel+0x70/0x70 net/socket.c:195 exit_to_usermode_loop+0x26c/0x360 arch/x86/entry/common.c:161 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Showing all locks held in the system: 1 lock held by khungtaskd/1141: #0: ffffffff899bea80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 1 lock held by in:imklog/6722: #0: ffff8880977bb5f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 4 locks held by kworker/u4:7/9497: 3 locks held by kworker/u4:9/27361: 2 locks held by syz-executor.0/23722: #0: ffff888050a63c90 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline] #0: ffff888050a63c90 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:604 #1: ffffffff8a5772f0 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1776 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1141 Comm: khungtaskd Not tainted 5.7.0-rc5-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 lapic_can_unplug_cpu.cold+0x3b/0x3b nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 reset_hung_task_detector+0x30/0x30 kernel/hung_task.c:243 kthread+0x388/0x470 kernel/kthread.c:268 kthread_mod_delayed_work+0x1a0/0x1a0 kernel/kthread.c:1090 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 21 Comm: kworker/u4:1 Not tainted 5.7.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_release kernel/locking/lockdep.c:4653 [inline] RIP: 0010:lock_release+0x2a1/0x800 kernel/locking/lockdep.c:4952 Code: 48 ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 0f b6 0c 11 48 89 fa 83 e2 07 83 c2 01 38 ca 7c 08 84 c9 0f 85 28 04 00 00 <66> f7 40 22 f0 ff 74 37 48 8d 78 20 48 ba 00 00 00 00 00 fc ff df RSP: 0018:ffffc90000dd7c00 EFLAGS: 00000046 RAX: ffff8880a97e8e98 RBX: 1ffff920001baf83 RCX: 0000000000000000 RDX: 0000000000000003 RSI: ffffffff899bea80 RDI: ffff8880a97e8eba RBP: ffff8880a97e8580 R08: ffff8880a97e8580 R09: fffffbfff1512b31 R10: ffffffff8a895987 R11: fffffbfff1512b30 R12: ffffffff899bea80 R13: ffffffff87b62516 R14: ffff8880a97e8e40 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4fac2e5000 CR3: 0000000096fc3000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: process_one_work+0x878/0x16a0 kernel/workqueue.c:2243 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 rcu_lock_release include/linux/rcupdate.h:213 [inline] rcu_read_unlock include/linux/rcupdate.h:655 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline] batadv_nc_worker+0x21c/0x760 net/batman-adv/network-coding.c:718 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 lock_release+0x800/0x800 kernel/locking/lockdep.c:4689 pwq_dec_nr_in_flight+0x310/0x310 kernel/workqueue.c:1198 rwlock_bug.part.0+0x90/0x90 include/linux/sched.h:1329 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 process_one_work+0x16a0/0x16a0 kernel/workqueue.c:2273 kthread+0x388/0x470 kernel/kthread.c:268 kthread_mod_delayed_work+0x1a0/0x1a0 kernel/kthread.c:1090 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351