INFO: task syz-executor.0:26664 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 D26144 26664 7062 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: 3 locks held by kworker/u4:4/184: 1 lock held by khungtaskd/1143: #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/6731: #0: ffff8880a816dd70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by agetty/6970: #0: ffff88809dd9f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000fd02e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x220/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.0/26664: #0: ffff888018016c90 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline] #0: ffff888018016c90 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:604 #1: ffffffff8a576f70 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1776 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1143 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: 4117 Comm: systemd-journal Not tainted 5.7.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mark_usage kernel/locking/lockdep.c:3819 [inline] RIP: 0010:__lock_acquire+0x846/0x4c50 kernel/locking/lockdep.c:4309 Code: 00 00 8b 44 24 08 85 c0 0f 84 6a 01 00 00 48 8d 7d 21 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 48 89 fa <83> e2 07 38 d0 7f 08 84 c0 0f 85 3e 39 00 00 4c 8d 75 22 44 0f b6 RSP: 0018:ffffc900016d7a48 EFLAGS: 00000802 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81592889 RDX: ffff8880a6b00b69 RSI: 0000000000000008 RDI: ffff8880a6b00b69 RBP: ffff8880a6b00b48 R08: 0000000000000001 R09: fffffbfff185cf2d R10: ffffffff8c2e7967 R11: fffffbfff185cf2c R12: ffff8880a6b00280 R13: 0000000000000002 R14: ffffffff8c2e7d80 R15: 0000000000000000 FS: 00007f00e74ee8c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f00e4b47000 CR3: 00000000a6cd4000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: path_openat+0xe63/0x27d0 fs/namei.c:3355 mark_held_locks+0xe0/0xe0 kernel/locking/lockdep.c:3620 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline] hlock_class kernel/locking/lockdep.c:179 [inline] lookup_chain_cache_add kernel/locking/lockdep.c:3146 [inline] validate_chain kernel/locking/lockdep.c:3202 [inline] __lock_acquire+0x2184/0x4c50 kernel/locking/lockdep.c:4355 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __debug_check_no_obj_freed lib/debugobjects.c:955 [inline] debug_check_no_obj_freed+0xc8/0x449 lib/debugobjects.c:998 lock_release+0x800/0x800 kernel/locking/lockdep.c:4689 do_filp_open+0x1b0/0x260 fs/namei.c:3378 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159 __debug_check_no_obj_freed lib/debugobjects.c:955 [inline] debug_check_no_obj_freed+0xc8/0x449 lib/debugobjects.c:998 __debug_check_no_obj_freed lib/debugobjects.c:955 [inline] debug_check_no_obj_freed+0xc8/0x449 lib/debugobjects.c:998 kmem_cache_free+0x185/0x320 mm/slab.c:3693 putname+0xe1/0x120 fs/namei.c:259 do_sys_openat2+0x467/0x7d0 fs/open.c:1157 file_open_root+0x400/0x400 fs/open.c:1129 __secure_computing+0x104/0x360 kernel/seccomp.c:950 syscall_trace_enter+0x41d/0xd10 arch/x86/entry/common.c:130 do_sys_open+0xc3/0x140 fs/open.c:1164 filp_open+0x70/0x70 fs/open.c:1117 trace_hardirqs_off_caller+0x55/0x230 kernel/trace/trace_preemptirq.c:73 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x7f00e6a7e840 Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24 RSP: 002b:00007ffd6831f178 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ffd6831f480 RCX: 00007f00e6a7e840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 000055d216c2c3f0 RBP: 000000000000000d R08: 000000000000ffc0 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 000055d216c1e060 R14: 00007ffd6831f440 R15: 000055d216c2c440