INFO: task syz.1.87:6230 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.87 state:D stack:26632 pid:6230 ppid:5765 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_timeout+0x9b/0x280 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+0x2bd/0x590 kernel/sched/completion.c:148
io_wq_exit_workers io_uring/io-wq.c:1266 [inline]
io_wq_put_and_exit+0x2f3/0x660 io_uring/io-wq.c:1294
io_uring_clean_tctx+0x120/0x190 io_uring/tctx.c:204
io_uring_cancel_generic+0x5f8/0x6a0 io_uring/io_uring.c:3507
io_uring_files_cancel include/linux/io_uring.h:69 [inline]
do_exit+0x5a7/0x23c0 kernel/exit.c:829
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
get_signal+0x12fc/0x1400 kernel/signal.c:2902
arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xf6/0x180 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+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fde4e38f749
RSP: 002b:00007fde4f2710e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fde4e5e6098 RCX: 00007fde4e38f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fde4e5e6098
RBP: 00007fde4e5e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fde4e5e6128 R14: 00007ffed9c7c520 R15: 00007ffed9c7c608
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:5/749:
#0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90003b57d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90003b57d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffffffff8dfa8610 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x136/0xb90 net/core/net_namespace.c:606
2 locks held by getty/5526:
#0: ffff8880316a20a0 (&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+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by syz-executor/5761:
2 locks held by kworker/1:4/5802:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000475fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000475fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
3 locks held by kworker/1:5/5828:
#0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000490fd00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000490fd00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
3 locks held by iou-wrk-6230/6238:
2 locks held by syz-executor/7273:
#0: ffffffff8dfa8610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x351/0x5e0 net/core/net_namespace.c:516
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
=============================================
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 10/25/2025
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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: 6245 Comm: iou-wrk-6230 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:native_read_msr_safe arch/x86/include/asm/msr.h:131 [inline]
RIP: 0010:__rdmsr_safe_on_cpu+0x3c/0x130 arch/x86/lib/msr-smp.c:158
Code: bd 00 00 00 00 00 fc ff df e8 20 02 33 fd 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 82 00 00 00 44 8b 23 44 89 e1 0f 32 <31> ed 49 89 c7 49 89 d6 0f 1f 44 00 00 e8 f2 01 33 fd 49 c1 e6 20
RSP: 0018:ffffc9000bf87408 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffc9000bf875e0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8afc6f60 RDI: ffffc9000bf875e0
RBP: ffffc9000bf87518 R08: ffffffff8e4a212f R09: 1ffffffff1c94425
R10: dffffc0000000000 R11: fffffbfff1c94426 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff84528e80 R15: 1ffff920017f0eb5
FS: 00007fde4f2716c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000b6c000 CR3: 000000002decc000 CR4: 00000000003506f0
Call Trace:
csd_do_func kernel/smp.c:133 [inline]
generic_exec_single+0x235/0x4f0 kernel/smp.c:404
smp_call_function_single_async+0x75/0x100 kernel/smp.c:695
rdmsr_safe_on_cpu+0x128/0x220 arch/x86/lib/msr-smp.c:181
msr_read+0x151/0x250 arch/x86/kernel/msr.c:66
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+0x1597/0x1a60 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+0x7ea/0x1120 io_uring/io-wq.c:602
io_wq_worker+0x470/0xea0 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