INFO: task syz-executor.5:18271 blocked for more than 140 seconds. Not tainted 4.19.93-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D27880 18271 8067 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: 0033:0x45af49 Code: Bad RIP value. RSP: 002b:00007fe2bd376c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49 RDX: 0000000020000100 RSI: 000000000000541c RDI: 0000000000000004 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe2bd3776d4 R13: 00000000004c64de R14: 00000000004ddae0 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1083: #0: 00000000415b5c7b (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438 1 lock held by rsyslogd/7884: #0: 00000000bba5141d (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by getty/8006: #0: 00000000eb01e008 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000067d00aa1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8007: #0: 00000000d0432b73 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000000d31ec5e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8008: #0: 00000000d0f88967 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000006d7d8e0f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8009: #0: 0000000067ef7a24 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000009614565c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8010: #0: 00000000287aa93d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000087beae53 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8011: #0: 0000000092edf66b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000005278561 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8012: #0: 00000000a589d74d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000003331c31c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 3 locks held by syz-executor.5/18208: 2 locks held by syz-executor.5/18271: #0: 00000000947af45e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000352c5c38 (&buf->lock){+.+.}, at: tty_buffer_lock_exclusive+0x30/0x40 drivers/tty/tty_buffer.c:61 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1083 Comm: khungtaskd Not tainted 4.19.93-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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 18208 Comm: syz-executor.5 Not tainted 4.19.93-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rcu_dynticks_curr_cpu_in_eqs+0x7f/0xb0 kernel/rcu/tree.c:351 Code: b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 14 8b 43 10 48 83 c4 08 5b <41> 5c 5d d1 e8 83 f0 01 83 e0 01 c3 4c 89 e7 e8 5d 5b 49 00 eb e2 RSP: 0018:ffff88804d5a7638 EFLAGS: 00000096 RAX: 0000000000073cd6 RBX: ffff88804f806080 RCX: ffffffff81597f91 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880ae823990 RBP: ffff88804d5a7640 R08: 1ffff11015d04732 R09: ffffed1015d04733 R10: ffffed1015d04732 R11: ffff8880ae823993 R12: ffff8880ae823990 R13: 0000000000001253 R14: ffff88804f806080 R15: 0000000000000000 FS: 00007fe2bd398700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 000000009f73c000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_is_watching+0x10/0x30 kernel/rcu/tree.c:1025 rcu_read_lock_held+0x81/0xd0 kernel/rcu/update.c:283 task_css include/linux/cgroup.h:482 [inline] task_ca kernel/sched/cpuacct.c:43 [inline] cpuacct_charge+0x2d1/0x360 kernel/sched/cpuacct.c:349 cgroup_account_cputime include/linux/cgroup.h:766 [inline] update_curr+0x2d7/0x8a0 kernel/sched/fair.c:829 pick_next_task_fair+0x6bf/0x1580 kernel/sched/fair.c:6698 pick_next_task kernel/sched/core.c:3361 [inline] __schedule+0x456/0x1dc0 kernel/sched/core.c:3489 schedule+0x92/0x1c0 kernel/sched/core.c:3559 paste_selection+0x2e8/0x443 drivers/tty/vt/selection.c:354 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: 0033:0x45af49 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe2bd397c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49 RDX: 0000000020000100 RSI: 000000000000541c RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe2bd3986d4 R13: 00000000004c64de R14: 00000000004ddae0 R15: 00000000ffffffff