INFO: task syz-executor.0:11662 blocked for more than 140 seconds. Not tainted 4.19.91-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29096 11662 13881 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 tty_buffer_lock_exclusive+0x30/0x40 drivers/tty/tty_buffer.c:61 paste_selection+0x11d/0x443 drivers/tty/vt/selection.c:348 tioclinux+0x133/0x470 drivers/tty/vt/vt.c:3019 vt_ioctl+0x19ab/0x2530 drivers/tty/vt/vt_ioctl.c:364 tty_ioctl+0x7f3/0x1510 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a919 Code: Bad RIP value. RSP: 002b:00007f8bbd386c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a919 RDX: 0000000020000000 RSI: 000000000000541c RDI: 0000000000000003 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8bbd3876d4 R13: 00000000004c5c45 R14: 00000000004dc038 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1068: #0: 000000009d0e02b4 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438 1 lock held by rsyslogd/7614: #0: 000000008e5d744b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by getty/7738: #0: 00000000a988c629 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000009ed46f4b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7739: #0: 000000001305510f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000099a69f37 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7740: #0: 00000000dc82615c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000008ad4df03 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7741: #0: 00000000e5aa1989 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000038a5b20 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7742: #0: 0000000019c93892 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000002c7248bb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by kworker/u4:5/10767: #0: 00000000126c8bfa (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1817 [inline] #0: 00000000126c8bfa (&rq->lock){-.-.}, at: __schedule+0x1f8/0x1dc0 kernel/sched/core.c:3453 #1: 000000009d0e02b4 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:428 [inline] #1: 000000009d0e02b4 (rcu_read_lock){....}, at: update_curr+0x2cc/0x8a0 kernel/sched/fair.c:828 2 locks held by getty/6370: #0: 00000000372d956a (&tty->legacy_mutex){+.+.}, at: tty_lock+0x73/0xb0 drivers/tty/tty_mutex.c:19 #1: 00000000a9550150 (&tty->ldisc_sem){++++}, at: ldsem_down_write+0x33/0x40 drivers/tty/tty_ldsem.c:388 2 locks held by syz-executor.0/11659: 2 locks held by syz-executor.0/11662: #0: 00000000a9550150 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000076b99bbb (&buf->lock){+.+.}, at: tty_buffer_lock_exclusive+0x30/0x40 drivers/tty/tty_buffer.c:61 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1068 Comm: khungtaskd Not tainted 4.19.91-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+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10767 Comm: kworker/u4:5 Not tainted 4.19.91-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:420 [inline] RIP: 0010:batadv_nc_worker+0x168/0x760 net/batman-adv/network-coding.c:730 Code: 89 e6 e8 cb ba 3b fa 45 84 e4 0f 84 75 03 00 00 e8 7d b9 3b fa 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 0f 85 61 05 00 00 4d 8b 36 46 e8 61 b9 3b fa 49 81 ee 88 01 00 00 74 47 e8 53 b9 3b fa 48 RSP: 0018:ffff88804aa4fce0 EFLAGS: 00000246 RAX: 1ffff11014af1e90 RBX: ffff8880576f3cc0 RCX: ffffffff872f8e49 RDX: 0000000000000000 RSI: ffffffff872f8ac3 RDI: 0000000000000001 RBP: ffff88804aa4fd30 R08: ffff8880497800c0 R09: ffffed1015d24733 R10: ffffed1015d24732 R11: ffff8880ae923993 R12: 0000000000000001 R13: 00000000000003d8 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42b8a78e8 CR3: 00000000921bc000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415