INFO: task syz-executor.5:12365 blocked for more than 143 seconds. Not tainted 5.9.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack:27904 pid:12365 ppid: 9374 flags:0x80004002 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 rwsem_down_write_slowpath+0x603/0xc60 kernel/locking/rwsem.c:1235 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1532 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1861 bcm_release+0x94/0x750 net/can/bcm.c:1474 __sock_release+0xcd/0x280 net/socket.c:596 sock_close+0x18/0x20 net/socket.c:1277 __fput+0x285/0x920 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:141 exit_task_work include/linux/task_work.h:25 [inline] do_exit+0xb7d/0x29f0 kernel/exit.c:806 do_group_exit+0x125/0x310 kernel/exit.c:903 get_signal+0x428/0x1f00 kernel/signal.c:2757 arch_do_signal+0x82/0x2520 arch/x86/kernel/signal.c:811 exit_to_user_mode_loop kernel/entry/common.c:135 [inline] exit_to_user_mode_prepare+0x15d/0x1c0 kernel/entry/common.c:166 syscall_exit_to_user_mode+0x59/0x2b0 kernel/entry/common.c:241 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d4d9 Code: Bad RIP value. RSP: 002b:00007f7a38a59c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: 0000000000000004 RBX: 0000000000032a40 RCX: 000000000045d4d9 RDX: 0000000000000002 RSI: 0000000000000002 RDI: 000000000000001d RBP: 000000000118d0c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118d08c R13: 00007ffe82c938af R14: 00007f7a38a5a9c0 R15: 000000000118d08c Showing all locks held in the system: 1 lock held by khungtaskd/1166: #0: ffffffff89bd6340 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5825 3 locks held by kworker/u4:6/4453: 1 lock held by in:imklog/6665: #0: ffff8880a8b65bb0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 3 locks held by kworker/u4:7/11490: 2 locks held by syz-executor.5/12365: #0: ffff888087a3a210 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:779 [inline] #0: ffff888087a3a210 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:595 #1: ffffffff8a7d8bf0 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1861 1 lock held by syz-executor.5/12470: #0: ffffffff8a7d8bf0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2ac/0x5e0 net/core/net_namespace.c:478 1 lock held by syz-executor.0/12487: #0: ffffffff8a7d8bf0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2ac/0x5e0 net/core/net_namespace.c:478 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1166 Comm: khungtaskd Not tainted 5.9.0-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+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd7d/0x1000 kernel/hung_task.c:295 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 11490 Comm: kworker/u4:7 Not tainted 5.9.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:hlock_class kernel/locking/lockdep.c:179 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3127 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3183 [inline] RIP: 0010:__lock_acquire+0x16af/0x5640 kernel/locking/lockdep.c:4426 Code: 01 00 00 00 c7 44 24 08 ff ff ff ff c7 44 24 50 ff ff ff ff c7 44 24 48 ff ff ff ff e9 a9 f3 ff ff 0f b7 5d 20 66 81 e3 ff 1f <0f> b7 db be 08 00 00 00 48 89 d8 48 c1 f8 06 48 8d 3c c5 e0 09 5f RSP: 0018:ffffc90008db79b8 EFLAGS: 00000006 RAX: 0000000000040000 RBX: 0000000000000635 RCX: 000000005e8d65d6 RDX: 1ffff1100c1481b3 RSI: 332454381a24b32d RDI: 000000002c92008b RBP: ffff888060a40d78 R08: 0000000000000000 R09: ffffffff8c5f0aa7 R10: fffffbfff18be154 R11: 1ffffffff137b288 R12: 0000000000000000 R13: 0000000000000000 R14: ffff888060a40440 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc9ea6ed000 CR3: 00000000928fc000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:5005 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175 spin_lock_bh include/linux/spinlock.h:359 [inline] batadv_nc_purge_paths+0xdf/0x3a0 net/batman-adv/network-coding.c:441 batadv_nc_worker+0x831/0xe50 net/batman-adv/network-coding.c:719 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294