INFO: task syz-executor.4:22486 blocked for more than 143 seconds. Not tainted 5.7.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28624 22486 7474 0x80004006 Call Trace: context_switch kernel/sched/core.c:3372 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4088 schedule+0x188/0x220 kernel/sched/core.c:4163 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:795 do_group_exit+0x15e/0x2c0 kernel/exit.c:893 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/u4:3/439: #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: ffffc90002627d80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x71e/0xfd0 kernel/workqueue.c:2243 #2: ffffffff895ac1f0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xac/0xb80 net/core/net_namespace.c:565 1 lock held by khungtaskd/1137: #0: ffffffff892e8590 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 net/mptcp/pm_netlink.c:858 1 lock held by in:imklog/6964: #0: ffff8880a79dab30 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x25d/0x2f0 fs/file.c:826 2 locks held by syz-executor.4/22486: #0: ffff888013946c90 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline] #0: ffff888013946c90 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: __sock_release net/socket.c:604 [inline] #0: ffff888013946c90 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: sock_close+0x94/0x260 net/socket.c:1283 #1: ffffffff895ac1f0 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x30/0x380 net/core/dev.c:1776 1 lock held by syz-executor.4/22644: #0: ffffffff895ac1f0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x31d/0x540 net/core/net_namespace.c:478 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1137 Comm: khungtaskd Not tainted 5.7.0-rc1-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: 4148 Comm: systemd-journal Not tainted 5.7.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x4bc/0x2c30 kernel/locking/lockdep.c:4303 Code: 00 44 8b 7d 28 45 89 65 00 48 8b 04 24 49 8d 9c c0 ec 08 00 00 48 89 d8 48 c1 e8 03 8a 04 30 84 c0 4d 89 ec 0f 85 43 14 00 00 <44> 89 3b 44 89 f3 48 89 d8 48 c1 e8 06 48 8d 3c c5 f0 74 14 8b be RSP: 0018:ffffc90001477b30 EFLAGS: 00000046 RAX: 1ffff11012627100 RBX: ffff888093138e6c RCX: 0000000000040000 RDX: 0000000000080000 RSI: dffffc0000000000 RDI: 0000000000000000 RBP: ffffc90001477c98 R08: ffff888093138580 R09: 0000000000000001 R10: fffffbfff12d7735 R11: 0000000000000000 R12: ffff888093138e68 R13: ffff888093138e68 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fd69ee958c0(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd69c367000 CR3: 0000000092c14000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x116c/0x2c30 kernel/locking/lockdep.c:4355 lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4934 __debug_check_no_obj_freed lib/debugobjects.c:955 [inline] debug_check_no_obj_freed+0xa9/0x640 lib/debugobjects.c:998 pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:650 [inline] queued_spin_unlock arch/x86/include/asm/qspinlock.h:55 [inline] do_raw_spin_unlock+0x134/0x8d0 kernel/locking/spinlock_debug.c:139 __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 kmem_cache_free+0x6b/0xf0 mm/slab.c:3693 do_sys_openat2+0x605/0x770 fs/open.c:1157 do_sys_open fs/open.c:1164 [inline] ksys_open include/linux/syscalls.h:1386 [inline] __do_sys_open fs/open.c:1170 [inline] __se_sys_open fs/open.c:1168 [inline] __x64_sys_open+0x1af/0x1e0 fs/open.c:1168 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x7fd69e425840 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:00007ffc6e48f198 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ffc6e48f4a0 RCX: 00007fd69e425840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 000055d5c3b07820 RBP: 000000000000000d R08: 000000000000c0ff R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 000055d5c3b03040 R14: 00007ffc6e48f460 R15: 000055d5c3b0eaf0