INFO: task syz-executor.5:17308 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.5 D26656 17308 7599 0x80004006 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4083 schedule+0x188/0x220 kernel/sched/core.c:4158 rwsem_down_write_slowpath+0x7d0/0xd60 kernel/locking/rwsem.c:1235 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x125/0x130 kernel/locking/rwsem.c:1532 unregister_netdevice_notifier+0x30/0x380 net/core/dev.c:1776 inode_lock include/linux/fs.h:797 [inline] __sock_release net/socket.c:604 [inline] sock_close+0x94/0x260 net/socket.c:1283 bcm_release+0x77/0x800 net/can/bcm.c:1474 atomic64_set include/asm-generic/atomic-instrumented.h:854 [inline] atomic_long_set include/asm-generic/atomic-long.h:40 [inline] rwsem_set_owner kernel/locking/rwsem.c:176 [inline] __down_write kernel/locking/rwsem.c:1391 [inline] down_write+0xcd/0x130 kernel/locking/rwsem.c:1532 __sock_release net/socket.c:605 [inline] sock_close+0xd8/0x260 net/socket.c:1283 sock_mmap+0x90/0x90 net/socket.c:1278 __fput+0x2ed/0x750 fs/file_table.c:280 task_work_run+0x147/0x1d0 kernel/task_work.c:123 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x5ef/0x1f80 kernel/exit.c:796 do_group_exit+0x15e/0x2c0 kernel/exit.c:894 get_signal+0x13cf/0x1d60 kernel/signal.c:2739 do_signal+0x33/0x610 arch/x86/kernel/signal.c:784 rcu_read_unlock_sched include/linux/rcupdate.h:732 [inline] __fd_install+0x251/0x490 fs/file.c:613 exit_to_usermode_loop arch/x86/entry/common.c:148 [inline] prepare_exit_to_usermode+0x280/0x600 arch/x86/entry/common.c:196 exit_to_usermode_loop arch/x86/entry/common.c:161 [inline] prepare_exit_to_usermode+0x32a/0x600 arch/x86/entry/common.c:196 syscall_return_slowpath+0xf9/0x420 arch/x86/entry/common.c:278 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Showing all locks held in the system: 3 locks held by kworker/u4:0/7: #0: ffff8880a9bb4938 ((wq_completion)netns){+.+.}-{0:0}, at: spin_unlock_irq include/linux/spinlock.h:403 [inline] #0: ffff8880a9bb4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x6df/0xfd0 kernel/workqueue.c:2241 #1: ffffc90000cdfd80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x71e/0xfd0 kernel/workqueue.c:2243 #2: ffffffff895ac3f0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xac/0xb80 net/core/net_namespace.c:565 3 locks held by kworker/u4:2/56: #0: ffff8880ae937518 (&rq->lock){-.-.}-{2:2}, at: newidle_balance+0x664/0xb20 kernel/sched/fair.c:10512 #1: ffffffff892e8550 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 net/mptcp/pm_netlink.c:860 #2: ffff8880ae927458 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:936 [inline] #2: ffff8880ae927458 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1e3/0x15e0 kernel/time/timer.c:1009 1 lock held by khungtaskd/1140: #0: ffffffff892e8550 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 net/mptcp/pm_netlink.c:860 1 lock held by in:imklog/6646: #0: ffff888099a29370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x25d/0x2f0 fs/file.c:826 2 locks held by syz-executor.5/17308: #0: ffff888030f87210 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline] #0: ffff888030f87210 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: __sock_release net/socket.c:604 [inline] #0: ffff888030f87210 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: sock_close+0x94/0x260 net/socket.c:1283 #1: ffffffff895ac3f0 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x30/0x380 net/core/dev.c:1776 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1140 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+0x1e9/0x30e lib/dump_stack.c:118 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101 arch_trigger_cpumask_backtrace+0x10/0x10 arch/x86/kernel/apic/hw_nmi.c:38 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xd2a/0xd40 kernel/hung_task.c:289 kthread+0x353/0x380 kernel/kthread.c:268 hungtask_pm_notify+0x50/0x50 kernel/hung_task.c:265 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4090 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:arch_local_save_flags arch/x86/include/asm/paravirt.h:754 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:776 [inline] RIP: 0010:lock_acquire+0xa9/0x480 kernel/locking/lockdep.c:4929 Code: 3c 10 00 74 16 48 c7 c7 28 b9 2b 89 e8 c0 c7 58 00 48 ba 00 00 00 00 00 fc ff df 48 83 3d a6 26 d3 07 00 0f 84 a2 03 00 00 9c <58> 0f 1f 44 00 00 48 89 44 24 20 48 c7 c0 38 b9 2b 89 48 c1 e8 03 RSP: 0018:ffffc90001657c98 EFLAGS: 00000086 RAX: 1ffffffff1257725 RBX: ffff888094aec400 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff8b745348 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: ffffed101295d97f R11: 0000000000000000 R12: ffff888094aeccc4 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff8b745348 FS: 00007f2638e8d8c0(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2636324000 CR3: 0000000094400000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x9e/0xc0 kernel/locking/spinlock.c:159 __debug_check_no_obj_freed lib/debugobjects.c:955 [inline] debug_check_no_obj_freed+0xa9/0x640 lib/debugobjects.c:998 __debug_check_no_obj_freed lib/debugobjects.c:955 [inline] debug_check_no_obj_freed+0xa9/0x640 lib/debugobjects.c:998 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0xb4/0xd0 kernel/locking/spinlock.c:191 kmem_cache_free+0x6b/0xf0 mm/slab.c:3693 file_free fs/file_table.c:55 [inline] __fput+0x51c/0x750 fs/file_table.c:298 task_work_run+0x147/0x1d0 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:165 [inline] prepare_exit_to_usermode+0x48e/0x600 arch/x86/entry/common.c:196 syscall_return_slowpath+0xf9/0x420 arch/x86/entry/common.c:278 entry_SYSCALL_64_after_hwframe+0x49/0xb3