INFO: task syz.4.503:8622 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.503 state:D stack:26600 pid:8622 ppid:6838 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0xc1/0x2d0 kernel/time/timer.c:2144
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common kernel/sched/completion.c:127 [inline]
wait_for_completion+0x2cb/0x5b0 kernel/sched/completion.c:148
io_wq_exit_workers io_uring/io-wq.c:1266 [inline]
io_wq_put_and_exit+0x474/0x810 io_uring/io-wq.c:1294
io_uring_clean_tctx+0x130/0x1b0 io_uring/tctx.c:204
io_uring_cancel_generic+0x610/0x6c0 io_uring/io_uring.c:3507
io_uring_files_cancel include/linux/io_uring.h:69 [inline]
do_exit+0x5f1/0x2460 kernel/exit.c:829
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
get_signal+0x12fc/0x13f0 kernel/signal.c:2902
arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f541bd9c819
RSP: 002b:00007f541cc570e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f541c015fa8 RCX: 00007f541bd9c819
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f541c015fa8
RBP: 00007f541c015fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f541c016038 R14: 00007fff394b9780 R15: 00007fff394b9868
Showing all locks held in the system:
3 locks held by kworker/u4:0/11:
#0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc90000107d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90000107d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#2: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286
1 lock held by khungtaskd/29:
#0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5532:
#0: ffff88814dbf80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
1 lock held by syz-executor/5758:
#0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa9/0x140 kernel/sched/core.c:567
1 lock held by syz-executor/5773:
2 locks held by kworker/1:6/7474:
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc90005597d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90005597d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
3 locks held by iou-wrk-8622/8623:
2 locks held by syz.7.699/9651:
#0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511
#1: ffffffff8d137a78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#1: ffffffff8d137a78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004
1 lock held by syz.5.701/9652:
#0: ffffffff8d137940 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf3d/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 8624 Comm: iou-wrk-8622 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:hlock_class kernel/locking/lockdep.c:223 [inline]
RIP: 0010:mark_lock+0x56/0x320 kernel/locking/lockdep.c:4656
Code: 03 42 0f b6 04 28 84 c0 0f 85 74 02 00 00 41 0f b6 47 02 24 03 3c 01 bd 09 00 00 00 83 dd 00 41 bc 01 00 00 00 89 e9 41 d3 e4 <4d> 8d 7e 20 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 22 02
RSP: 0018:ffffc9000541f2a0 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffff888024800000 RCX: 0000000000000007
RDX: 0000000000000007 RSI: ffff888024800ae0 RDI: ffff888024800000
RBP: 0000000000000007 R08: ffffffff911c5537 R09: 1ffffffff2238aa6
R10: dffffc0000000000 R11: fffffbfff2238aa7 R12: 0000000000000080
R13: dffffc0000000000 R14: ffff888024800ae0 R15: ffff888024800b00
FS: 00007f541cc576c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000006fe000 CR3: 0000000023d18000 CR4: 00000000003526f0
Call Trace:
mark_usage kernel/locking/lockdep.c:-1 [inline]
__lock_acquire+0x11c7/0x7d40 kernel/locking/lockdep.c:5091
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
__might_fault+0xc6/0x120 mm/memory.c:5968
_copy_to_user+0x2a/0xa0 lib/usercopy.c:36
copy_to_user include/linux/uaccess.h:191 [inline]
msr_read+0x17e/0x250 arch/x86/kernel/msr.c:69
loop_rw_iter+0x35a/0x580 io_uring/rw.c:-1
io_iter_do_read io_uring/rw.c:662 [inline]
__io_read io_uring/rw.c:783 [inline]
io_read+0x164b/0x1b20 io_uring/rw.c:884
io_issue_sqe+0x289/0xc90 io_uring/io_uring.c:1869
io_wq_submit_work+0x418/0x9c0 io_uring/io_uring.c:1956
io_worker_handle_work+0x847/0x11b0 io_uring/io-wq.c:602
io_wq_worker+0x4a0/0xf10 io_uring/io-wq.c:656
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293