INFO: task syz.6.732:7500 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.732 state:D stack:27888 pid: 7500 ppid: 6889 flags:0x00004004 Call Trace: <TASK> context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2093 __down_common+0x289/0x3b0 kernel/locking/semaphore.c:228 down+0x7e/0xd0 kernel/locking/semaphore.c:63 console_lock+0x29/0x70 kernel/printk/printk.c:2557 con_font_set drivers/tty/vt/vt.c:4663 [inline] con_font_op+0x8d9/0xdc0 drivers/tty/vt/vt.c:4715 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:476 [inline] vt_ioctl+0x1618/0x1ca0 drivers/tty/vt/vt_ioctl.c:754 tty_ioctl+0x848/0xc30 drivers/tty/tty_io.c:2810 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc1f5902159 RSP: 002b:00007fc1f3b18028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc1f5b8a180 RCX: 00007fc1f5902159 RDX: 00002000000001c0 RSI: 0000000000004b72 RDI: 0000000000000005 RBP: 00007fc1f599906b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc1f5b8a218 R14: 00007fc1f5b8a180 R15: 00007ffde52ed538 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3945: #0: ffff88814d83e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 4 locks held by kworker/u4:8/4348: 2 locks held by kworker/u4:10/4354: 2 locks held by kworker/0:10/4406: 1 lock held by syz.3.724/7462: 1 lock held by syz-executor/8253: 6 locks held by syz.8.974/8606: 1 lock held by syz.4.976/8611: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: <TASK> dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe1b/0xe60 kernel/hung_task.c:369 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 </TASK>