INFO: task syz.8.4695:25504 blocked for more than 143 seconds.
Not tainted 6.16.0-rc7-syzkaller-00034-g25fae0b93d1d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.4695 state:D stack:28296 pid:25504 tgid:25499 ppid:24703 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6879
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
blk_trace_startstop+0xa3/0x640 kernel/trace/blktrace.c:700
blk_trace_ioctl+0x19b/0x430 kernel/trace/blktrace.c:742
blkdev_common_ioctl+0xdce/0x2450 block/ioctl.c:629
blkdev_ioctl+0x4ef/0x6d0 block/ioctl.c:698
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f534078e9a9
RSP: 002b:00007f5341554038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f53409b6080 RCX: 00007f534078e9a9
RDX: 0000000000000000 RSI: 0000000000001274 RDI: 0000000000000003
RBP: 00007f5340810d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f53409b6080 R15: 00007f5340adfa28
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
1 lock held by kworker/u8:3/49:
#0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:614
1 lock held by udevd/5217:
2 locks held by getty/5611:
#0: ffff8880354ba0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000331e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by kworker/u8:12/9860:
4 locks held by kworker/0:1/11666:
5 locks held by kworker/u8:0/21082:
3 locks held by kworker/u8:2/21196:
#0: ffff88801b2fe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801b2fe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc9000ae6fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000ae6fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffffffff8e144ac0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786
2 locks held by syz.8.4695/25500:
1 lock held by syz.8.4695/25504:
#0: ffff888142f03a08 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_startstop+0xa3/0x640 kernel/trace/blktrace.c:700
2 locks held by syz.1.5068/27271:
#0: ffffffff8f51c148 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline]
#0: ffffffff8f51c148 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396
#1: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#1: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998
2 locks held by iou-sqp-27285/27286:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-00034-g25fae0b93d1d #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 25500 Comm: syz.8.4695 Not tainted 6.16.0-rc7-syzkaller-00034-g25fae0b93d1d #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409
Code: e8 2e f9 79 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 0f 0b dc fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 8a 45 2a 06 cc 44 89 f9 80 e1 07
RSP: 0018:ffffc9000403ed30 EFLAGS: 00000002
RAX: 1ffffffff33bec00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffffff99df6590 R08: ffff888024710237 R09: 1ffff110048e2046
R10: dffffc0000000000 R11: ffffffff85462d50 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff99df6300 R15: 0000000000000000
FS: 00007f53415756c0(0000) GS:ffff888125d23000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2ae6f83178 CR3: 0000000068d52000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 3a810b1eb6134bdc DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:137 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
wait_for_lsr+0x1a1/0x2f0 drivers/tty/serial/8250/8250_port.c:2094
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline]
serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456
console_emit_next_record kernel/printk/printk.c:3138 [inline]
console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
_printk+0xcf/0x120 kernel/printk/printk.c:2475
show_free_areas mm/show_mem.c:232 [inline]
__show_mem+0xd0a/0x21b0 mm/show_mem.c:403
warn_alloc_show_mem mm/page_alloc.c:3719 [inline]
warn_alloc+0x2dd/0x310 mm/page_alloc.c:3744
__vmalloc_area_node mm/vmalloc.c:3702 [inline]
__vmalloc_node_range_noprof+0x67e/0x12f0 mm/vmalloc.c:3893
__kvmalloc_node_noprof+0x3b8/0x5f0 mm/slub.c:5037
kvmalloc_array_node_noprof include/linux/slab.h:1065 [inline]
relay_alloc_page_array kernel/relay.c:63 [inline]
relay_alloc_buf kernel/relay.c:116 [inline]
relay_create_buf kernel/relay.c:162 [inline]
relay_open_buf+0x217/0xd40 kernel/relay.c:383
relay_open+0x427/0x920 kernel/relay.c:512
do_blk_trace_setup+0x591/0x9d0 kernel/trace/blktrace.c:590
blk_trace_setup+0x116/0x1f0 kernel/trace/blktrace.c:632
blk_trace_ioctl+0x181/0x430 kernel/trace/blktrace.c:730
blkdev_ioctl+0x416/0x6d0 block/ioctl.c:693
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f534078e9a9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5341575038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f53409b5fa0 RCX: 00007f534078e9a9
RDX: 0000200000000140 RSI: 00000000c0481273 RDI: 0000000000000003
RBP: 00007f5340810d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f53409b5fa0 R15: 00007f5340adfa28