INFO: task syz-executor.0:25058 blocked for more than 140 seconds. Not tainted 4.19.140-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D30272 25058 6492 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x3aa/0x760 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x4f/0x90 kernel/locking/rwsem.c:72 register_netdevice_notifier+0x7b/0x5b0 net/core/dev.c:1639 raw_init+0x296/0x340 net/can/raw.c:343 can_create+0x27c/0x470 net/can/af_can.c:184 __sock_create+0x3d8/0x740 net/socket.c:1276 sock_create net/socket.c:1316 [inline] __sys_socket+0xef/0x200 net/socket.c:1346 __do_sys_socket net/socket.c:1355 [inline] __se_sys_socket net/socket.c:1353 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1353 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45d4d9 Code: Bad RIP value. RSP: 002b:00007f433983cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000032ac0 RCX: 000000000045d4d9 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffd8414b67f R14: 00007f433983d9c0 R15: 000000000118cf4c Showing all locks held in the system: 1 lock held by khungtaskd/1088: #0: 0000000021a7688e (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440 1 lock held by in:imklog/6173: #0: 000000000523e688 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 2 locks held by agetty/6228: #0: 000000002296449d (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000000a70e058 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1950 drivers/tty/n_tty.c:2154 2 locks held by syz-executor.2/23589: 1 lock held by syz-executor.0/25058: #0: 00000000068e28db (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0x7b/0x5b0 net/core/dev.c:1639 1 lock held by syz-executor.0/25061: #0: 00000000068e28db (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0x7b/0x5b0 net/core/dev.c:1639 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1088 Comm: khungtaskd Not tainted 4.19.140-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+0x1fc/0x2fe lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x30b/0x410 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22732 Comm: kworker/u4:3 Not tainted 4.19.140-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:find_held_lock+0x1a2/0x210 kernel/locking/lockdep.c:3543 Code: ff df 4c 89 f2 48 c1 ea 03 0f b6 14 02 4c 89 f0 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 35 5b 45 89 2e 4c 89 e0 5d 41 5c 41 5d <41> 5e 41 5f c3 4c 89 fe 4c 89 e7 e8 1e eb ff ff 85 c0 0f 84 d3 fe RSP: 0018:ffff888050e0fbe8 EFLAGS: 00000097 RAX: ffff88804b57cad8 RBX: ffffffff8b915aa0 RCX: ffff888050e0fc38 RDX: 0000000000000004 RSI: ffffffff88d93820 RDI: ffff88804b57cae8 RBP: ffffffff88d93820 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1100a1c1f83 R13: ffffffff87219245 R14: ffff888050e0fc38 R15: ffffffff88d93820 FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fceb45be000 CR3: 00000000a5b92000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_release kernel/locking/lockdep.c:3676 [inline] lock_release+0x246/0x8b0 kernel/locking/lockdep.c:3926 rcu_lock_release include/linux/rcupdate.h:247 [inline] rcu_read_unlock include/linux/rcupdate.h:681 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:423 [inline] batadv_nc_worker+0x66c/0xd50 net/batman-adv/network-coding.c:730 process_one_work+0x864/0x1570 kernel/workqueue.c:2155 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298 kthread+0x30b/0x410 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415