INFO: task syz.0.3485:16804 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.3485 state:D stack:28808 pid:16804 tgid:16800 ppid:15264 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
blk_trace_startstop+0x8f/0x610 kernel/trace/blktrace.c:903
sg_ioctl_common drivers/scsi/sg.c:-1 [inline]
sg_ioctl+0xb0c/0x21b0 drivers/scsi/sg.c:1157
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffbd199e0d9
RSP: 002b:00007ffbd28cf028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffbd1c26090 RCX: 00007ffbd199e0d9
RDX: 0000000000000000 RSI: 0000000000001274 RDI: 0000000000000009
RBP: 00007ffbd1a35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffbd1c26128 R14: 00007ffbd1c26090 R15: 00007ffbd1d4fa48
INFO: task syz.0.3485:16805 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.3485 state:D stack:28720 pid:16805 tgid:16800 ppid:15264 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
sg_ioctl_common drivers/scsi/sg.c:1123 [inline]
sg_ioctl+0x457/0x21b0 drivers/scsi/sg.c:1157
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffbd199e0d9
RSP: 002b:00007ffbd28ae028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffbd1c26180 RCX: 00007ffbd199e0d9
RDX: 0000000000000000 RSI: 0000000000001276 RDI: 0000000000000009
RBP: 00007ffbd1a35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffbd1c26218 R14: 00007ffbd1c26180 R15: 00007ffbd1d4fa48
Showing all locks held in the system:
6 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/30:
#0: ffffffff8eb59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8eb59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8eb59ca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by khugepaged/37:
4 locks held by kworker/u8:5/82:
#0: ffff88801c296140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801c296140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9000200fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9000200fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff90019868 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673
#3: ffffffff90028400 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xe5/0x9e0 net/core/dev.c:13091
2 locks held by udevd/4980:
2 locks held by getty/5376:
#0: ffff88823be940a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
3 locks held by syz.0.3485/16801:
1 lock held by syz.0.3485/16804:
#0: ffff888025ea91f8 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
#0: ffff888025ea91f8 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_startstop+0x8f/0x610 kernel/trace/blktrace.c:903
1 lock held by syz.0.3485/16805:
#0: ffff888025ea91f8 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
#0: ffff888025ea91f8 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 82 Comm: kworker/u8:5 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: netns cleanup_net
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401
Code: e8 7e 8c 60 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 1f 36 ce fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc9000200f128 EFLAGS: 00000002
RAX: 1ffffffff355c400 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: dffffc0000000000 R08: ffff888141ac8237 R09: 1ffff11028359046
R10: dffffc0000000000 R11: ffffffff856674e0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9aae24a0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125049000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd91afe46b0 CR3: 000000007f056000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000460
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x184/0x2f0 drivers/tty/serial/8250/8250_port.c:1982
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3235 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3300 [inline]
serial8250_console_write+0x12ef/0x1ba0 drivers/tty/serial/8250/8250_port.c:3385
console_emit_next_record kernel/printk/printk.c:3183 [inline]
console_flush_one_record kernel/printk/printk.c:3269 [inline]
console_flush_all+0x6ea/0xaf0 kernel/printk/printk.c:3343
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
_printk+0xdd/0x130 kernel/printk/printk.c:2504
batadv_hardif_disable_interface+0x2b8/0xe20 net/batman-adv/hard-interface.c:831
batadv_meshif_destroy_netlink+0x59/0xa0 net/batman-adv/mesh-interface.c:1098
default_device_exit_batch+0x744/0x9e0 net/core/dev.c:13100
ops_exit_list net/core/net_namespace.c:205 [inline]
ops_undo_list+0x4b4/0x8d0 net/core/net_namespace.c:252
cleanup_net+0x572/0x810 net/core/net_namespace.c:702
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245