INFO: task syz-executor.5:2506 blocked for more than 143 seconds. Not tainted 5.7.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D26672 2506 7618 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/u4:4/182: #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: ffffc900016b7d80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x71e/0xfd0 kernel/workqueue.c:2243 #2: ffffffff895ac230 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xac/0xb80 net/core/net_namespace.c:565 1 lock held by khungtaskd/1141: #0: ffffffff892e8550 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 net/mptcp/pm_netlink.c:860 2 locks held by syz-executor.5/2506: #0: ffff888086e26750 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline] #0: ffff888086e26750 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: __sock_release net/socket.c:604 [inline] #0: ffff888086e26750 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: sock_close+0x94/0x260 net/socket.c:1283 #1: ffffffff895ac230 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x30/0x380 net/core/dev.c:1776 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1141 Comm: khungtaskd Not tainted 5.7.0-rc4-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:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 18259 Comm: kworker/u4:7 Not tainted 5.7.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: 0x0 (bat_events) RIP: 0010:clear_buddies kernel/sched/fair.c:4265 [inline] RIP: 0010:pick_next_entity+0x362/0xab0 kernel/sched/fair.c:4458 Code: 00 10 00 0f 85 b1 02 00 00 49 39 fc 7f 17 43 80 3c 2f 00 48 8b 5c 24 20 74 08 48 89 df e8 c6 3a 5f 00 4c 8b 33 48 8b 44 24 10 <42> 80 3c 28 00 48 8b 5c 24 18 74 08 48 89 df e8 aa 3a 5f 00 4d 85 RSP: 0018:ffffc90017af7c40 EFLAGS: 00000046 RAX: 1ffff11015d26eba RBX: 0000000000000000 RCX: 1ffff11015d26eb2 RDX: ffffc90017af7d68 RSI: 0000000000000000 RDI: ffff8880ae937580 RBP: ffff8880ae9375c8 R08: dffffc0000000000 R09: fffffbfff12d7765 R10: fffffbfff12d7765 R11: 0000000000000000 R12: ffff8880ae9375d0 R13: dffffc0000000000 R14: ffff8880a96f04c0 R15: 1ffff11015d26eb9 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000160 CR3: 000000009242d000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pick_next_task_fair+0x19b/0xfb0 kernel/sched/fair.c:6986 pick_next_task kernel/sched/core.c:3921 [inline] __schedule+0x365/0xc90 kernel/sched/core.c:4051 schedule+0x188/0x220 kernel/sched/core.c:4158 worker_thread+0xf76/0x1450 kernel/workqueue.c:2435 kthread+0x353/0x380 kernel/kthread.c:268 rcu_lock_release+0x20/0x20 include/linux/rcupdate.h:213 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352