syzbot

INFO: task kworker/1:1:46 blocked for more than 143 seconds.
      Not tainted 6.14.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:1     state:D stack:21936 pid:46    tgid:46    ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: events console_callback
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6857
 schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75
 ___down_common+0x2d7/0x460 kernel/locking/semaphore.c:229
 __down_common kernel/locking/semaphore.c:250 [inline]
 __down+0x20/0x30 kernel/locking/semaphore.c:258
 down+0x74/0xa0 kernel/locking/semaphore.c:64
 console_lock+0x5b/0xa0 kernel/printk/printk.c:2833
 console_callback+0x63/0x4c0 drivers/tty/vt/vt.c:3120
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task kworker/1:3:5867 blocked for more than 143 seconds.
      Not tainted 6.14.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:3     state:D stack:21136 pid:5867  tgid:5867  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: events vc_SAK
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6857
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914
 __mutex_lock_common kernel/locking/mutex.c:662 [inline]
 __mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730
 tty_buffer_flush+0x72/0x310 drivers/tty/tty_buffer.c:229
 tty_ldisc_flush+0x64/0xe0 drivers/tty/tty_ldisc.c:388
 __do_SAK+0x6a7/0x800 drivers/tty/tty_io.c:3037
 vc_SAK+0x7f/0x310 drivers/tty/vt/vt_ioctl.c:993
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task kworker/u8:20:8816 blocked for more than 143 seconds.
      Not tainted 6.14.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:20   state:D stack:24752 pid:8816  tgid:8816  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: events_unbound flush_to_ldisc
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6857
 schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75
 ___down_common+0x2d7/0x460 kernel/locking/semaphore.c:229
 __down_common kernel/locking/semaphore.c:250 [inline]
 __down+0x20/0x30 kernel/locking/semaphore.c:258
 down+0x74/0xa0 kernel/locking/semaphore.c:64
 console_lock+0x5b/0xa0 kernel/printk/printk.c:2833
 do_con_write+0x154/0x7bb0 drivers/tty/vt/vt.c:3056
 con_put_char+0x74/0xa0 drivers/tty/vt/vt.c:3440
 tty_put_char+0xbc/0x160 drivers/tty/tty_io.c:3166
 n_tty_process_echo_ops drivers/tty/n_tty.c:663 [inline]
 __process_echoes+0x7fe/0xb40 drivers/tty/n_tty.c:709
 flush_echoes drivers/tty/n_tty.c:807 [inline]
 __receive_buf drivers/tty/n_tty.c:1642 [inline]
 n_tty_receive_buf_common+0xa2a/0x1980 drivers/tty/n_tty.c:1739
 tty_ldisc_receive_buf+0xa2/0x190 drivers/tty/tty_buffer.c:387
 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:445 [inline]
 flush_to_ldisc+0x264/0x780 drivers/tty/tty_buffer.c:495
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task syz.1.1292:10515 blocked for more than 143 seconds.
      Not tainted 6.14.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1292      state:D stack:28152 pid:10515 tgid:10514 ppid:5816   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6857
 schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75
 ___down_common+0x2d7/0x460 kernel/locking/semaphore.c:229
 __down_common kernel/locking/semaphore.c:250 [inline]
 __down+0x20/0x30 kernel/locking/semaphore.c:258
 down+0x74/0xa0 kernel/locking/semaphore.c:64
 console_lock+0x5b/0xa0 kernel/printk/printk.c:2833
 con_install+0x9a/0x600 drivers/tty/vt/vt.c:3515
 tty_driver_install_tty drivers/tty/tty_io.c:1304 [inline]
 tty_init_dev.part.0+0x99/0x660 drivers/tty/tty_io.c:1416
 tty_init_dev include/linux/err.h:67 [inline]
 tty_open_by_driver drivers/tty/tty_io.c:2082 [inline]
 tty_open+0xac1/0xf80 drivers/tty/tty_io.c:2129
 chrdev_open+0x237/0x6a0 fs/char_dev.c:414
 do_dentry_open+0x735/0x1c40 fs/open.c:956
 vfs_open+0x82/0x3f0 fs/open.c:1086
 do_open fs/namei.c:3830 [inline]
 path_openat+0x1e88/0x2d80 fs/namei.c:3989
 do_filp_open+0x20c/0x470 fs/namei.c:4016
 do_sys_openat2+0x17a/0x1e0 fs/open.c:1428
 do_sys_open fs/open.c:1443 [inline]
 __do_sys_openat fs/open.c:1459 [inline]
 __se_sys_openat fs/open.c:1454 [inline]
 __x64_sys_openat+0x175/0x210 fs/open.c:1454
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdff918bad0
RSP: 002b:00007fdffa047b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fdff918bad0
RDX: 0000000000000002 RSI: 00007fdffa047c10 RDI: 00000000ffffff9c
RBP: 00007fdffa047c10 R08: 0000000000000000 R09: 00007fdffa047986
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdff93a5fa0 R15: 00007ffef4d17a98
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
 watchdog+0xf62/0x12b0 kernel/hung_task.c:399
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:csd_do_func kernel/smp.c:134 [inline]
RIP: 0010:__flush_smp_call_function_queue+0x4c7/0x8c0 kernel/smp.c:587
Code: 1a 0c 00 4d 85 f6 75 97 e8 06 1a 0c 00 48 8b 1c 24 48 85 db 74 2b e8 f8 19 0c 00 48 89 de 48 c7 c7 50 55 8a 81 e8 39 f9 ff ff <48> 89 df e8 c1 7e dc ff 48 89 de 48 c7 c7 50 55 8a 81 e8 22 f7 ff
RSP: 0018:ffffc90000a28f90 EFLAGS: 00000046
RAX: 0000000080010001 RBX: ffff88807db3c8b8 RCX: ffffffff81add13f
RDX: ffff88801d6f0000 RSI: ffffffff81add687 RDI: 0000000000000001
RBP: 0000000000000030 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffffc90000a28ff8 R12: ffff88807db3c8b8
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88807db3c8c0
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f15cd69ff98 CR3: 0000000154760000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000004144
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __sysvec_call_function_single+0x8c/0x410 arch/x86/kernel/smp.c:271
 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline]
 sysvec_call_function_single+0x9f/0xc0 arch/x86/kernel/smp.c:266
 </IRQ>
 <TASK>
 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709
RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline]
RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline]
RIP: 0010:acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:112
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 05 08 28 ac 74 48 8b 00 a8 08 75 0c 66 90 0f 00 2d f8 0a 87 00 fb f4 <fa> c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900001b7d58 EFLAGS: 00000246
RAX: 0000000000004000 RBX: 0000000000000001 RCX: ffffffff8b579469
RDX: 0000000000000001 RSI: ffff8880206d5000 RDI: ffff8880206d5064
RBP: ffff8880206d5064 R08: 0000000000000000 R09: ffffed10170e6f85
R10: ffff8880b8737c2b R11: 0000000000000001 R12: ffff88802036a800
R13: ffffffff8ee2eba0 R14: 0000000000000001 R15: 0000000000000000
 acpi_idle_enter+0xc5/0x160 drivers/acpi/processor_idle.c:699
 cpuidle_enter_state+0xaa/0x4f0 drivers/cpuidle/cpuidle.c:268
 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:389
 cpuidle_idle_call kernel/sched/idle.c:230 [inline]
 do_idle+0x310/0x3f0 kernel/sched/idle.c:325
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423
 start_secondary+0x222/0x2b0 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x148
 </TASK>