INFO: task syz-executor.2:19992 blocked for more than 143 seconds. Not tainted 5.6.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D26720 19992 7334 0x90004006 Call Trace: context_switch kernel/sched/core.c:3380 [inline] __schedule+0x7c9/0xc50 kernel/sched/core.c:4080 schedule+0x188/0x220 kernel/sched/core.c:4154 rwsem_down_write_slowpath+0x7d0/0xd60 kernel/locking/rwsem.c:1238 hlock_class kernel/locking/lockdep.c:175 [inline] __lock_acquire+0xc20/0x1bc0 kernel/locking/lockdep.c:3951 __down_write kernel/locking/rwsem.c:1392 [inline] down_write+0x125/0x130 kernel/locking/rwsem.c:1535 unregister_netdevice_notifier+0x30/0x380 net/core/dev.c:1776 lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484 inode_lock include/linux/fs.h:792 [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:177 [inline] __down_write kernel/locking/rwsem.c:1394 [inline] down_write+0xcd/0x130 kernel/locking/rwsem.c:1535 __sock_release net/socket.c:605 [inline] sock_close+0xd8/0x260 net/socket.c:1283 sock_mmap+0x90/0x90 net/socket.c:1278 __fput+0x2d8/0x730 fs/file_table.c:280 task_work_run+0x176/0x1b0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x5ef/0x1f80 kernel/exit.c:801 do_group_exit+0x15e/0x2c0 kernel/exit.c:899 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 get_signal+0x13cf/0x1d60 kernel/signal.c:2739 alloc_file+0x86/0x4b0 fs/file_table.c:197 do_signal+0x33/0x610 arch/x86/kernel/signal.c:813 check_preemption_disabled+0x40/0x240 lib/smp_processor_id.c:16 exit_to_usermode_loop arch/x86/entry/common.c:160 [inline] prepare_exit_to_usermode+0x32a/0x600 arch/x86/entry/common.c:195 syscall_return_slowpath+0xf9/0x420 arch/x86/entry/common.c:277 entry_SYSCALL_64_after_hwframe+0x49/0xbe INFO: task syz-executor.2:20001 blocked for more than 143 seconds. Not tainted 5.6.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28512 20001 7334 0x90004006 Call Trace: context_switch kernel/sched/core.c:3380 [inline] __schedule+0x7c9/0xc50 kernel/sched/core.c:4080 schedule+0x188/0x220 kernel/sched/core.c:4154 rwsem_down_write_slowpath+0x7d0/0xd60 kernel/locking/rwsem.c:1238 hlock_class kernel/locking/lockdep.c:175 [inline] __lock_acquire+0xc21/0x1bc0 kernel/locking/lockdep.c:3951 __down_write kernel/locking/rwsem.c:1392 [inline] down_write+0x125/0x130 kernel/locking/rwsem.c:1535 unregister_netdevice_notifier+0x30/0x380 net/core/dev.c:1776 lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484 inode_lock include/linux/fs.h:792 [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:177 [inline] __down_write kernel/locking/rwsem.c:1394 [inline] down_write+0xcd/0x130 kernel/locking/rwsem.c:1535 __sock_release net/socket.c:605 [inline] sock_close+0xd8/0x260 net/socket.c:1283 sock_mmap+0x90/0x90 net/socket.c:1278 __fput+0x2d8/0x730 fs/file_table.c:280 task_work_run+0x176/0x1b0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x5ef/0x1f80 kernel/exit.c:801 do_group_exit+0x15e/0x2c0 kernel/exit.c:899 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 get_signal+0x13cf/0x1d60 kernel/signal.c:2739 alloc_file+0x86/0x4b0 fs/file_table.c:197 do_signal+0x33/0x610 arch/x86/kernel/signal.c:813 check_preemption_disabled+0x40/0x240 lib/smp_processor_id.c:16 exit_to_usermode_loop arch/x86/entry/common.c:160 [inline] prepare_exit_to_usermode+0x32a/0x600 arch/x86/entry/common.c:195 syscall_return_slowpath+0xf9/0x420 arch/x86/entry/common.c:277 entry_SYSCALL_64_after_hwframe+0x49/0xbe Showing all locks held in the system: 3 locks held by kworker/u4:2/64: #0: ffff8880a9b73d28 ((wq_completion)netns){+.+.}, at: spin_unlock_irq include/linux/spinlock.h:388 [inline] #0: ffff8880a9b73d28 ((wq_completion)netns){+.+.}, at: process_one_work+0x6df/0xfd0 kernel/workqueue.c:2239 #1: ffffc90000fc7d88 (net_cleanup_work){+.+.}, at: process_one_work+0x71e/0xfd0 kernel/workqueue.c:2241 #2: ffffffff8938efa8 (pernet_ops_rwsem){++++}, at: cleanup_net+0xac/0xb80 net/core/net_namespace.c:551 1 lock held by khungtaskd/1137: #0: ffffffff890d9ac8 (rcu_read_lock){....}, at: rcu_lock_acquire+0x0/0x30 lib/xarray.c:75 1 lock held by in:imklog/6716: #0: ffff88809f43b3a0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:826 2 locks held by syz-executor.2/19992: #0: ffff888011051c80 (&sb->s_type->i_mutex_key#14){+.+.}, at: inode_lock include/linux/fs.h:792 [inline] #0: ffff888011051c80 (&sb->s_type->i_mutex_key#14){+.+.}, at: __sock_release net/socket.c:604 [inline] #0: ffff888011051c80 (&sb->s_type->i_mutex_key#14){+.+.}, at: sock_close+0x94/0x260 net/socket.c:1283 #1: ffffffff8938efa8 (pernet_ops_rwsem){++++}, at: unregister_netdevice_notifier+0x30/0x380 net/core/dev.c:1776 2 locks held by syz-executor.2/20001: #0: ffff8880110c7c80 (&sb->s_type->i_mutex_key#14){+.+.}, at: inode_lock include/linux/fs.h:792 [inline] #0: ffff8880110c7c80 (&sb->s_type->i_mutex_key#14){+.+.}, at: __sock_release net/socket.c:604 [inline] #0: ffff8880110c7c80 (&sb->s_type->i_mutex_key#14){+.+.}, at: sock_close+0x94/0x260 net/socket.c:1283 #1: ffffffff8938efa8 (pernet_ops_rwsem){++++}, at: unregister_netdevice_notifier+0x30/0x380 net/core/dev.c:1776 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1137 Comm: khungtaskd Not tainted 5.6.0-rc7-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+0x317/0x340 kernel/kthread.c:255 hungtask_pm_notify+0x50/0x50 kernel/hung_task.c:265 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1234 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: 4234 Comm: systemd-journal Not tainted 5.6.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__kernel_text_address+0x0/0x40 kernel/extable.c:103 Code: 50 fa 07 01 76 bb eb d1 66 90 48 c7 c0 00 00 00 89 48 39 c7 0f 93 c0 48 c7 c1 00 ac 4b 89 48 39 cf 0f 92 c1 20 c1 0f b6 c1 c3 <53> 48 89 fb e8 37 00 00 00 85 c0 0f 95 c0 48 c7 c1 00 20 63 8a 48 RSP: 0018:ffffc9000d7ff9e8 EFLAGS: 00000046 RAX: 1ffff92001afff00 RBX: ffffc9000d7ffa58 RCX: 1ffff92001afff49 RDX: ffffc9000d7ffa10 RSI: ffffc9000d7ff950 RDI: ffffffff8163d05d RBP: ffffc9000d7ffa98 R08: ffffc9000d7ffaa8 R09: ffffc9000d7ffa10 R10: fffff52001afff4d R11: 0000000000000000 R12: ffff888092d72580 R13: ffffffff8163d100 R14: dffffc0000000000 R15: 1ffff92001afff4b FS: 00007f2fbfcc48c0(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2fbd129018 CR3: 0000000092de4000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_get_return_address+0x48/0x90 arch/x86/kernel/unwind_orc.c:314 arch_stack_walk+0x98/0xe0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xad/0x150 kernel/stacktrace.c:123 putname fs/namei.c:259 [inline] filename_lookup+0x41b/0x5d0 fs/namei.c:2475 stack_trace_save+0xad/0x150 kernel/stacktrace.c:123 save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0x12e/0x1e0 mm/kasan/common.c:476 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_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0xb4/0xd0 kernel/locking/spinlock.c:191 __debug_check_no_obj_freed lib/debugobjects.c:977 [inline] debug_check_no_obj_freed+0x592/0x640 lib/debugobjects.c:998 putname fs/namei.c:259 [inline] filename_lookup+0x41b/0x5d0 fs/namei.c:2475 __cache_free mm/slab.c:3426 [inline] kmem_cache_free+0x7e/0xf0 mm/slab.c:3694 putname fs/namei.c:259 [inline] filename_lookup+0x41b/0x5d0 fs/namei.c:2475 audit_dummy_context include/linux/audit.h:296 [inline] audit_getname include/linux/audit.h:327 [inline] getname_flags+0x20d/0x610 fs/namei.c:202 user_path_at include/linux/namei.h:58 [inline] do_faccessat+0x2ca/0x780 fs/open.c:398 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f2fbef809c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffded2580e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffded25b000 RCX: 00007f2fbef809c7 RDX: 00007f2fbf9f1a00 RSI: 0000000000000000 RDI: 00005648011f29a3 RBP: 00007ffded258120 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffded25b000 R15: 00007ffded258610