INFO: task syz.2.8431:26887 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.2.8431 state:D stack:24632 pid:26887 tgid:26880 ppid:5621 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f9/0x5500 kernel/sched/core.c:7197
__schedule_loop kernel/sched/core.c:7276 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7291
cgroup_lock_and_drain_offline+0x516/0x650 kernel/cgroup/cgroup.c:3248
cgroup_kn_lock_live+0x120/0x230 kernel/cgroup/cgroup.c:1699
cgroup_subtree_control_write+0x4b3/0x10a0 kernel/cgroup/cgroup.c:3550
cgroup_file_write+0x331/0x8f0 kernel/cgroup/cgroup.c:4289
kernfs_fop_write_iter+0x3b0/0x540 fs/kernfs/file.c:352
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x629/0xba0 fs/read_write.c:688
ksys_write+0x156/0x270 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f71d126ce59
RSP: 002b:00007f71cf4a5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f71d14e6090 RCX: 00007f71d126ce59
RDX: 0000000000000008 RSI: 0000200000000040 RDI: 0000000000000009
RBP: 00007f71d1302d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f71d14e6128 R14: 00007f71d14e6090 R15: 00007ffd577bd738
Showing all locks held in the system:
1 lock held by ktimers/0/16:
#0: ffffffff8de612c0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
1 lock held by khungtaskd/39:
#0: ffffffff8dfca240 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfca240 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfca240 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777
2 locks held by kworker/u9:0/60:
#0: ffff888027263138 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc9000126fc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
2 locks held by kworker/u9:1/4931:
#0: ffff888027263138 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc9000f9cfc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
2 locks held by getty/5375:
#0: ffff8880364c40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
2 locks held by kworker/u9:2/5618:
#0: ffff888027263138 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc900051bfc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
2 locks held by kworker/u8:16/12853:
#0: ffff88813fe84138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc9001d0c7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
4 locks held by kworker/u8:21/12861:
#0: ffff88813fe82938 ((wq_completion)kvfree_rcu_reclaim){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc9001d117c40 ((work_completion)(&(&krcp->krw_arr[i].rcu_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
#2: ffffffff8dfca360 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#2: ffffffff8dfca360 (rcu_callback){....}-{0:0}, at: kvfree_rcu_bulk+0x6d/0x1b0 mm/slab_common.c:1496
#3: ffffffff8dfca240 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff8dfca240 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#3: ffffffff8dfca240 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
#3: ffffffff8dfca240 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa6/0x2550 arch/x86/kernel/unwind_orc.c:495
3 locks held by syz.2.8431/26887:
#0: ffff88803fa28b28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1260
#1: ffff88803d0c4480 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
#1: ffff88803d0c4480 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684
#2: ffff888040bb2078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
2 locks held by modprobe/28435:
#0: ffff888037a683b0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline]
#0: ffff888037a683b0 (&mm->mmap_lock){++++}-{4:4}, at: __do_sys_brk mm/mmap.c:126 [inline]
#0: ffff888037a683b0 (&mm->mmap_lock){++++}-{4:4}, at: __se_sys_brk+0x164/0xba0 mm/mmap.c:116
#1: ffff888068f5a968 (&anon_vma->rwsem){++++}-{4:4}, at: anon_vma_lock_read mm/internal.h:236 [inline]
#1: ffff888068f5a968 (&anon_vma->rwsem){++++}-{4:4}, at: validate_mm+0x1e3/0x4c0 mm/vma.c:680
9 locks held by syz.9.8770/28442:
#0: ffff8880331dde48 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
#1: ffffc90007727b00 (&x->wait#58){-...}-{2:2}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffc90007727b00 (&x->wait#58){-...}-{2:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#1: ffffc90007727b00 (&x->wait#58){-...}-{2:2}, at: count_memcg_events_mm include/linux/memcontrol.h:970 [inline]
#1: ffffc90007727b00 (&x->wait#58){-...}-{2:2}, at: count_memcg_event_mm+0x21/0x260 include/linux/memcontrol.h:980
#2: ffffc90007727b00 (&x->wait#58){-...}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:664
#3: ffff8880b8724508 (psi_seq){-...}-{0:0}, at: psi_task_change+0xd4/0x340 kernel/sched/psi.c:919
#4: ffff8880b863b860 (&rq->__lock){-...}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:664
#5: ffff8880b8724508 (psi_seq){-...}-{0:0}, at: psi_task_change+0xd4/0x340 kernel/sched/psi.c:919
#6: ffff8880b863b860 (&rq->__lock){-...}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:664
#7: ffff8880b8724508 (psi_seq){-...}-{0:0}, at: psi_task_change+0xd4/0x340 kernel/sched/psi.c:919
#8: ffff8880b8724508 (psi_seq){-...}-{0:0}, at: psi_task_change+0xd4/0x340 kernel/sched/psi.c:919
2 locks held by syz-executor/28451:
#0: ffffffff8dfca240 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfca240 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfca240 (rcu_read_lock){....}-{1:3}, at: path_init+0x12d/0x14d0 fs/namei.c:2685
#1: ffff8880b8640258 ((&pcs->lock)){+.+.}-{3:3}, at: alloc_from_pcs mm/slub.c:4757 [inline]
#1: ffff8880b8640258 ((&pcs->lock)){+.+.}-{3:3}, at: slab_alloc_node mm/slub.c:4897 [inline]
#1: ffff8880b8640258 ((&pcs->lock)){+.+.}-{3:3}, at: __kmalloc_cache_noprof+0x1a0/0x690 mm/slub.c:5420
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
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+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x389/0x470 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__preempt_count_add kernel/rcu/tree.c:748 [inline]
RIP: 0010:rcu_is_watching+0x6/0xb0 kernel/rcu/tree.c:751
Code: e8 7f db 3f 03 eb cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 65 ff 05 30 7f c8 10 e8 cb bf 81 09 89 c3 83 f8 08 73 65
RSP: 0000:ffffc90000157ab0 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81cd39bc
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8f8b9d30
RBP: ffffc90000157be8 R08: ffffffff8f8b9d37 R09: 1ffffffff1f173a6
R10: dffffc0000000000 R11: fffffbfff1f173a7 R12: dffffc0000000000
R13: 1ffff9200002af68 R14: ffff88804c251ba0 R15: ffff88804c251ba0
FS: 0000000000000000(0000) GS:ffff888125efc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1d4a4aa540 CR3: 0000000072966000 CR4: 00000000003526f0
Call Trace:
trace_irq_disable+0x3b/0x140 include/trace/events/preemptirq.h:36
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:130 [inline]
_raw_spin_lock_irqsave+0x1a/0x60 kernel/locking/spinlock.c:166
rt_mutex_slowunlock+0xbf/0x8b0 kernel/locking/rtmutex.c:1426
spin_unlock_irqrestore include/linux/spinlock_rt.h:129 [inline]
skb_dequeue+0x11a/0x150 net/core/skbuff.c:3946
ieee80211_handle_queued_frames+0x4a/0x1e0 net/mac80211/main.c:445
tasklet_action_common+0x31c/0x610 kernel/softirq.c:942
handle_softirqs+0x1de/0x6d0 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
run_ktimerd+0x69/0x100 kernel/softirq.c:1155
smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
kthread+0x389/0x470 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