INFO: task agetty:23424 blocked for more than 143 seconds. Not tainted 5.15.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:agetty state:D stack:27024 pid:23424 ppid: 1 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 rwsem_down_write_slowpath+0x7b9/0x11d0 kernel/locking/rwsem.c:1107 __down_write_common kernel/locking/rwsem.c:1262 [inline] __down_write_common kernel/locking/rwsem.c:1259 [inline] __down_write kernel/locking/rwsem.c:1271 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1518 tty_set_termios+0xfe/0x910 drivers/tty/tty_ioctl.c:352 set_termios.part.0+0x30e/0x530 drivers/tty/tty_ioctl.c:438 set_termios drivers/tty/tty_ioctl.c:392 [inline] tty_mode_ioctl+0xd0e/0xe70 drivers/tty/tty_ioctl.c:728 n_tty_ioctl_helper+0x53/0x2d0 drivers/tty/tty_ioctl.c:907 n_tty_ioctl+0x56/0x370 drivers/tty/n_tty.c:2421 tty_ioctl+0xc69/0x1670 drivers/tty/tty_io.c:2814 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f735ee066b8 RSP: 002b:00007ffee5440950 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000010 RCX: 00007f735ee066b8 RDX: 00007ffee54408f0 RSI: 0000000000005402 RDI: 0000000000000000 RBP: 00007ffee54408f0 R08: 0000000000000000 R09: 00007ffee5440a20 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 000055ee0280d900 R14: 00007ffee54409e0 R15: 0000000000000012 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8b97fe60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 2 locks held by kworker/u4:2/150: 1 lock held by in:imklog/6226: #0: ffff88801acaeff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by agetty/23424: #0: ffff888074a41098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252 #1: ffff888074a412e8 (&tty->termios_rwsem){++++}-{3:3}, at: tty_set_termios+0xfe/0x910 drivers/tty/tty_ioctl.c:352 5 locks held by syz-executor.2/23560: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:295 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 150 Comm: kworker/u4:2 Not tainted 5.15.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:match_held_lock+0xe/0xc0 kernel/locking/lockdep.c:5077 Code: 48 c7 c7 20 fb 8b 89 e8 aa 19 be ff e8 37 e1 cc ff 31 c0 5d c3 0f 1f 80 00 00 00 00 53 48 89 fb 48 83 ec 08 48 39 77 10 74 6a <66> f7 47 22 f0 ff 74 5a 48 8b 46 08 48 89 f7 48 85 c0 74 42 8b 15 RSP: 0018:ffffc900016efae0 EFLAGS: 00000083 RAX: 000000000000000a RBX: ffff8880120edfc8 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8b97fda0 RDI: ffff8880120edfc8 RBP: ffffffff8b97fda0 R08: 0000000000000000 R09: ffff8880b9c32a0b R10: ffffed1017386541 R11: 0000000000000000 R12: ffff8880120ed580 R13: ffff8880120edf78 R14: 00000000ffffffff R15: ffff8880120edfc8 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c001c433c8 CR3: 000000000b68e000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __lock_is_held kernel/locking/lockdep.c:5368 [inline] lock_is_held_type+0xa7/0x140 kernel/locking/lockdep.c:5668 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5636 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:174 [inline] _raw_spin_unlock_bh+0x12/0x30 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:408 [inline] batadv_nc_purge_paths+0x2a5/0x3a0 net/batman-adv/network-coding.c:473 batadv_nc_worker+0x8f9/0xfa0 net/batman-adv/network-coding.c:722 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 48 c7 c7 20 fb 8b 89 mov $0xffffffff898bfb20,%rdi 7: e8 aa 19 be ff callq 0xffbe19b6 c: e8 37 e1 cc ff callq 0xffcce148 11: 31 c0 xor %eax,%eax 13: 5d pop %rbp 14: c3 retq 15: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 1c: 53 push %rbx 1d: 48 89 fb mov %rdi,%rbx 20: 48 83 ec 08 sub $0x8,%rsp 24: 48 39 77 10 cmp %rsi,0x10(%rdi) 28: 74 6a je 0x94 * 2a: 66 f7 47 22 f0 ff testw $0xfff0,0x22(%rdi) <-- trapping instruction 30: 74 5a je 0x8c 32: 48 8b 46 08 mov 0x8(%rsi),%rax 36: 48 89 f7 mov %rsi,%rdi 39: 48 85 c0 test %rax,%rax 3c: 74 42 je 0x80 3e: 8b .byte 0x8b 3f: 15 .byte 0x15