INFO: task kworker/u8:8:6335 blocked for more than 143 seconds.
Tainted: G I L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:8 state:D stack:21184 pid:6335 tgid:6335 ppid:2 task_flags:0x4208160 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe4/0x5e10 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
__flush_workqueue+0x3f7/0x1200 kernel/workqueue.c:4033
rxrpc_destroy_all_connections+0xf9/0x420 net/rxrpc/conn_object.c:477
rxrpc_exit_net+0x7b/0xc0 net/rxrpc/net_ns.c:113
ops_exit_list net/core/net_namespace.c:199 [inline]
ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252
cleanup_net+0x419/0x830 net/core/net_namespace.c:696
process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
INFO: task syz.0.944:11645 blocked for more than 143 seconds.
Tainted: G I L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.944 state:D stack:22712 pid:11645 tgid:11645 ppid:6425 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe4/0x5e10 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
__flush_work+0x7c7/0xcb0 kernel/workqueue.c:4277
vkms_atomic_commit_tail+0x172/0x240 drivers/gpu/drm/vkms/vkms_drv.c:86
commit_tail+0x293/0x430 drivers/gpu/drm/drm_atomic_helper.c:2071
drm_atomic_helper_commit+0x303/0x380 drivers/gpu/drm/drm_atomic_helper.c:2311
drm_atomic_commit+0x230/0x300 drivers/gpu/drm/drm_atomic.c:1743
drm_client_modeset_commit_atomic+0x6a6/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1103
drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1206
drm_client_modeset_commit+0x4f/0x80 drivers/gpu/drm/drm_client_modeset.c:1232
__drm_fb_helper_restore_fbdev_mode_unlocked.part.0+0x137/0x160 drivers/gpu/drm/drm_fb_helper.c:235
__drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:223 [inline]
drm_fb_helper_restore_fbdev_mode_unlocked+0x93/0xc0 drivers/gpu/drm/drm_fb_helper.c:266
drm_fbdev_client_restore+0x1b/0x30 drivers/gpu/drm/clients/drm_fbdev_client.c:45
drm_client_dev_restore+0x205/0x2a0 drivers/gpu/drm/drm_client_event.c:118
drm_lastclose drivers/gpu/drm/drm_file.c:408 [inline]
drm_release+0x2c6/0x360 drivers/gpu/drm/drm_file.c:441
__fput+0x3ff/0xb40 fs/file_table.c:468
task_work_run+0x150/0x240 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ea/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f727359aeb9
RSP: 002b:00007ffc2682e1b8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f7273817da0 RCX: 00007f727359aeb9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f7273817da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007f7273817cb0 R11: 0000000000000246 R12: 000000000007f10c
R13: 00007f727381627c R14: 000000000007f012 R15: 00007f7273816270
INFO: task syz.4.950:11683 blocked for more than 143 seconds.
Tainted: G I L syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.950 state:D stack:28264 pid:11683 tgid:11679 ppid:11358 task_flags:0x40054c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe4/0x5e10 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
__flush_workqueue+0x3f7/0x1200 kernel/workqueue.c:4033
rxrpc_release_sock net/rxrpc/af_rxrpc.c:965 [inline]
rxrpc_release+0x2a7/0x6a0 net/rxrpc/af_rxrpc.c:996
__sock_release+0xb3/0x260 net/socket.c:662
sock_close+0x1c/0x30 net/socket.c:1455
__fput+0x3ff/0xb40 fs/file_table.c:468
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x829/0x2a30 kernel/exit.c:971
do_group_exit+0xd5/0x2a0 kernel/exit.c:1112
get_signal+0x1ec7/0x21e0 kernel/signal.c:3034
arch_do_signal_or_restart+0x91/0x770 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x86/0x4b0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ea/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fef8099aeb9
RSP: 002b:00007fef818e2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: fffffffffffffe00 RBX: 00007fef80c16090 RCX: 00007fef8099aeb9
RDX: 0000000000000076 RSI: 0000200000000440 RDI: 0000000000000000
RBP: 00007fef80a08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fef80c16128 R14: 00007fef80c16090 R15: 00007ffd28cced38
INFO: task syz.3.955:11718 blocked for more than 143 seconds.
Tainted: G I L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.955 state:D stack:28488 pid:11718 tgid:11714 ppid:5828 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe4/0x5e10 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
class_mutex_constructor include/linux/mutex.h:253 [inline]
drm_master_open+0x78/0x220 drivers/gpu/drm/drm_auth.c:325
drm_open_helper+0x42b/0x540 drivers/gpu/drm/drm_file.c:340
drm_open+0x1a0/0x3e0 drivers/gpu/drm/drm_file.c:388
drm_stub_open+0x20f/0x380 drivers/gpu/drm/drm_drv.c:1208
chrdev_open+0x234/0x6a0 fs/char_dev.c:414
do_dentry_open+0x73e/0x1570 fs/open.c:962
vfs_open+0x82/0x3f0 fs/open.c:1094
do_open fs/namei.c:4637 [inline]
path_openat+0x21dc/0x3120 fs/namei.c:4796
do_filp_open+0x1f7/0x420 fs/namei.c:4823
do_sys_openat2+0x12e/0x220 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f24adb9aeb9
RSP: 002b:00007f24aea11028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f24ade16090 RCX: 00007f24adb9aeb9
RDX: 0000000000101002 RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 00007f24adc08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f24ade16128 R14: 00007f24ade16090 R15: 00007ffc9eaf3b78
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:8/6335:
#0: ffff88801c29f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc90002f87c98 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffffffff903dcef0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x830 net/core/net_namespace.c:670
2 locks held by getty/7428:
#0: ffff88814cfdc0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032442f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:0/10720:
#0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc9000fb57c98 ((work_completion)(&helper->damage_work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffff888140590280 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_fb_dirty drivers/gpu/drm/drm_fb_helper.c:333 [inline]
#2: ffff888140590280 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_damage_work+0x159/0x640 drivers/gpu/drm/drm_fb_helper.c:372
3 locks held by kworker/u11:3/11630:
6 locks held by syz.0.944/11645:
#0: ffff8880261b6270 (&dev->clientlist_mutex){+.+.}-{4:4}, at: drm_client_dev_restore+0xe9/0x2a0 drivers/gpu/drm/drm_client_event.c:113
#1: ffff888140590280 (&helper->lock){+.+.}-{4:4}, at: __drm_fb_helper_restore_fbdev_mode_unlocked.part.0+0x21/0x160 drivers/gpu/drm/drm_fb_helper.c:226
#2: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_internal_acquire+0x21/0x80 drivers/gpu/drm/drm_auth.c:435
#3: ffff888140590098 (&client->modeset_mutex){+.+.}-{4:4}, at: drm_client_modeset_commit_locked+0x4c/0x580 drivers/gpu/drm/drm_client_modeset.c:1204
#4: ffffc90002f27b38 (crtc_ww_class_acquire){+.+.}-{0:0}, at: drm_client_modeset_commit_atomic+0xc4/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1042
#5: ffffc90002f27b60 (crtc_ww_class_mutex){+.+.}-{4:4}, at: drm_client_modeset_commit_atomic+0xc4/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1042
1 lock held by syz.4.950/11683:
#0: ffff888012a72488 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff888012a72488 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:661
1 lock held by syz.3.955/11718:
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_open+0x78/0x220 drivers/gpu/drm/drm_auth.c:325
1 lock held by syz.2.982/11926:
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_open+0x78/0x220 drivers/gpu/drm/drm_auth.c:325
1 lock held by syz.5.1004/12086:
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_open+0x78/0x220 drivers/gpu/drm/drm_auth.c:325
1 lock held by syz.8.1038/12309:
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_open+0x78/0x220 drivers/gpu/drm/drm_auth.c:325
1 lock held by syz.1.1127/12841:
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_open+0x78/0x220 drivers/gpu/drm/drm_auth.c:325
1 lock held by syz.6.1147/12967:
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_open+0x78/0x220 drivers/gpu/drm/drm_auth.c:325
3 locks held by syz.9.1153/12999:
#0: ffffffff8e5cf320 (console_lock){+.+.}-{0:0}, at: do_fb_ioctl+0x1d9/0x7e0 drivers/video/fbdev/core/fb_chrdev.c:86
#1: ffff8880261bd078 (&fb_info->lock){+.+.}-{4:4}, at: lock_fb_info include/linux/fb.h:623 [inline]
#1: ffff8880261bd078 (&fb_info->lock){+.+.}-{4:4}, at: do_fb_ioctl+0x1e3/0x7e0 drivers/video/fbdev/core/fb_chrdev.c:87
#2: ffff888140590280 (&helper->lock){+.+.}-{4:4}, at: __drm_fb_helper_restore_fbdev_mode_unlocked.part.0+0x21/0x160 drivers/gpu/drm/drm_fb_helper.c:226
1 lock held by syz.0.1180/13147:
#0: ffff8880261bd078 (&fb_info->lock){+.+.}-{4:4}, at: lock_fb_info include/linux/fb.h:623 [inline]
#0: ffff8880261bd078 (&fb_info->lock){+.+.}-{4:4}, at: fb_open+0xa1/0x3d0 drivers/video/fbdev/core/fb_chrdev.c:350
2 locks held by syz.4.1192/13236:
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x539/0xfa0 drivers/tty/tty_io.c:2120
#1: ffff88804750a1c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev.part.0+0x39/0x470 drivers/tty/tty_io.c:1406
1 lock held by syz.3.1198/13282:
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x539/0xfa0 drivers/tty/tty_io.c:2120
1 lock held by syz.2.1219/13388:
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x539/0xfa0 drivers/tty/tty_io.c:2120
1 lock held by syz.2.1219/13389:
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x539/0xfa0 drivers/tty/tty_io.c:2120
1 lock held by syz.5.1239/13532:
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x539/0xfa0 drivers/tty/tty_io.c:2120
4 locks held by syz.8.1248/13575:
#0: ffff888159652b78 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1255
#1: ffff888032802420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738
#2: ffff8880753e5488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
#3: ffff8881412a3f08 (kn->active#201){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#3: ffff8881412a3f08 (kn->active#201){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
1 lock held by syz.7.1258/13621:
#0: ffff88804bd94148 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff88804bd94148 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:661
1 lock held by syz.1.1260/13643:
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x539/0xfa0 drivers/tty/tty_io.c:2120
1 lock held by syz.6.1261/13674:
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x539/0xfa0 drivers/tty/tty_io.c:2120
1 lock held by syz.9.1271/13766:
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#0: ffff8880261b6128 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_open+0x78/0x220 drivers/gpu/drm/drm_auth.c:325
1 lock held by syz.0.1272/13786:
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x539/0xfa0 drivers/tty/tty_io.c:2120
1 lock held by syz.0.1272/13789:
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x539/0xfa0 drivers/tty/tty_io.c:2120
1 lock held by syz.4.1268/13797:
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x539/0xfa0 drivers/tty/tty_io.c:2120
1 lock held by syz.3.1274/13832:
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2d67a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x539/0xfa0 drivers/tty/tty_io.c:2120
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G I L syzkaller #0 PREEMPT(full)
Tainted: [I]=FIRMWARE_WORKAROUND, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xcc3/0xfe0 kernel/hung_task.c:515
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246