INFO: task syz.0.2287:16834 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2287 state:D stack:28872 pid:16834 tgid:16833 ppid:5861 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760
tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
chrdev_open+0x234/0x6a0 fs/char_dev.c:414
do_dentry_open+0x982/0x1530 fs/open.c:965
vfs_open+0x82/0x3f0 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x1de4/0x2cb0 fs/namei.c:4046
do_filp_open+0x20b/0x470 fs/namei.c:4073
do_sys_openat2+0x11b/0x1d0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f04fc18ebe9
RSP: 002b:00007f04fcff0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f04fc3c5fa0 RCX: 00007f04fc18ebe9
RDX: 0000000000000102 RSI: 0000200000000800 RDI: ffffffffffffff9c
RBP: 00007f04fc211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f04fc3c6038 R14: 00007f04fc3c5fa0 R15: 00007fff10c00ae8
INFO: task syz.4.2288:16836 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2288 state:D stack:26536 pid:16836 tgid:16835 ppid:10166 task_flags:0x400140 flags:0x00404004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
___down_common+0x2d8/0x460 kernel/locking/semaphore.c:268
__down_common kernel/locking/semaphore.c:293 [inline]
__down+0x20/0x30 kernel/locking/semaphore.c:303
down+0x74/0xa0 kernel/locking/semaphore.c:100
console_lock+0x5b/0xa0 kernel/printk/printk.c:2849
show_cons_active+0x208/0x6f0 drivers/tty/tty_io.c:3569
dev_attr_show+0x53/0xe0 drivers/base/core.c:2421
sysfs_kf_seq_show+0x216/0x3e0 fs/sysfs/file.c:65
seq_read_iter+0x509/0x12c0 fs/seq_file.c:230
kernfs_fop_read_iter+0x40f/0x5a0 fs/kernfs/file.c:279
new_sync_read fs/read_write.c:491 [inline]
vfs_read+0x8bc/0xcf0 fs/read_write.c:572
ksys_read+0x12a/0x250 fs/read_write.c:715
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8c6698ebe9
RSP: 002b:00007f8c6771f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f8c66bc5fa0 RCX: 00007f8c6698ebe9
RDX: 0000000000000038 RSI: 0000200000000300 RDI: 0000000000000006
RBP: 00007f8c66a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8c66bc6038 R14: 00007f8c66bc5fa0 R15: 00007fff1553c1b8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5c10a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5c10a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e5c10a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
3 locks held by kworker/1:2/981:
2 locks held by getty/5625:
#0: ffff88814db260a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
2 locks held by kworker/u10:1/8490:
#0: ffff8881466e1948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc90003fafd10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
2 locks held by kworker/u10:9/8962:
#0: ffff8881466e1948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc90003a37d10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
2 locks held by syz.3.2267/16755:
#0: ffffffff9042a310 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9d9788 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1919
4 locks held by syz.1.2282/16821:
1 lock held by syz.0.2287/16834:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
5 locks held by syz.4.2288/16836:
#0: ffff88805c858b78 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1232
#1: ffff88806e587540 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
#2: ffff888025584488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#3: ffff8880236913c8 (kn->active#132){.+.+}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
#4: ffffffff8e5af048 (console_mutex){+.+.}-{4:4}, at: show_cons_active+0x92/0x6f0 drivers/tty/tty_io.c:3550
1 lock held by syz.5.2296/16913:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
5 locks held by syz.6.2297/16977:
#0: ffff8880572a3b38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1232
#1: ffff88807e1311c8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
#2: ffff888057d8e888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#3: ffff8880236913c8 (kn->active#132){.+.+}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
#4: ffffffff8e5af048 (console_mutex){+.+.}-{4:4}, at: show_cons_active+0x92/0x6f0 drivers/tty/tty_io.c:3550
1 lock held by syz.7.2291/16984:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
5 locks held by syz.8.2301/17005:
#0: ffff88805c9e3cf8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1232
#1: ffff88807a56fc30 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
#2: ffff88807a6fd888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#3: ffff8880236913c8 (kn->active#132){.+.+}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
#4: ffffffff8e5af048 (console_mutex){+.+.}-{4:4}, at: show_cons_active+0x92/0x6f0 drivers/tty/tty_io.c:3550
1 lock held by syz.9.2304/17043:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.9.2304/17044:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.3.2305/17195:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.1.2311/17312:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.0.2313/17343:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.4.2320/17430:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.6.2316/17473:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.7.2324/17500:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.9.2344/17664:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.9.2344/17674:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.3.2346/17693:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.8.2363/17773:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.8.2363/17782:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.2.2365/17784:
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2cba88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
2 locks held by syz.1.2358/17816:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
__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:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf0e/0x1260 kernel/hung_task.c:491
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245