INFO: task syz.0.17:6667 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17 state:D stack:25480 pid:6667 tgid:6666 ppid:6557 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
io_schedule+0x81/0xe0 kernel/sched/core.c:7903
folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1317
folio_wait_writeback+0xb0/0x100 mm/page-writeback.c:3124
__filemap_fdatawait_range+0x147/0x230 mm/filemap.c:539
file_write_and_wait_range+0x290/0x340 mm/filemap.c:798
v9fs_file_fsync+0xd2/0x1b0 fs/9p/vfs_file.c:418
generic_write_sync include/linux/fs.h:3043 [inline]
netfs_file_write_iter+0x3dc/0x4a0 fs/netfs/buffered_write.c:494
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5d2/0xb40 fs/read_write.c:686
ksys_write+0x14b/0x260 fs/read_write.c:738
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: 0033:0x7f6c3dbdebe9
RSP: 002b:00007f6c3d246038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6c3de05fa0 RCX: 00007f6c3dbdebe9
RDX: 0000000000007fec RSI: 0000200000000300 RDI: 0000000000000007
RBP: 00007f6c3dc61e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6c3de06038 R14: 00007f6c3de05fa0 R15: 00007ffc8195afc8
Showing all locks held in the system:
2 locks held by kworker/u8:1/13:
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90000127bc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90000127bc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
1 lock held by khungtaskd/38:
#0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:2/43:
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90000b47bc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90000b47bc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
2 locks held by kworker/u8:3/57:
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000123fbc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000123fbc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
2 locks held by kworker/u8:4/67:
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000152fbc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000152fbc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
2 locks held by kworker/u8:5/84:
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000157fbc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000157fbc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
2 locks held by kworker/u8:6/155:
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90003a57bc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90003a57bc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
2 locks held by kworker/u8:8/2229:
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90006357bc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90006357bc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
2 locks held by kworker/u8:10/3495:
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000d917bc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000d917bc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
2 locks held by kworker/u8:12/3567:
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000db97bc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000db97bc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
5 locks held by kworker/u8:14/3610:
2 locks held by getty/5596:
#0: ffff88823bf420a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222
2 locks held by syz.0.17/6667:
#0: ffff8880354bdb28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x253/0x320 fs/file.c:1232
#1: ffff88803b57e488 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline]
#1: ffff88803b57e488 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
2 locks held by syz.1.18/6740:
#0: ffff888032e0a128 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x253/0x320 fs/file.c:1232
#1: ffff888023fd8488 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline]
#1: ffff888023fd8488 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
2 locks held by syz.2.19/6763:
#0: ffff8880407dd328 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x253/0x320 fs/file.c:1232
#1: ffff88803dc26488 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline]
#1: ffff88803dc26488 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
2 locks held by syz.3.21/6790:
#0: ffff8880354b9128 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x253/0x320 fs/file.c:1232
#1: ffff888029762488 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline]
#1: ffff888029762488 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
2 locks held by syz.4.22/6824:
#0: ffff888029ef4b28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x253/0x320 fs/file.c:1232
#1: ffff88803c032488 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline]
#1: ffff88803c032488 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
2 locks held by syz.5.23/6855:
#0: ffff888032098f28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x253/0x320 fs/file.c:1232
#1: ffff88805c9b8488 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline]
#1: ffff88805c9b8488 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
2 locks held by syz.6.24/6885:
#0: ffff88802412a928 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x253/0x320 fs/file.c:1232
#1: ffff88805b52e488 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline]
#1: ffff88805b52e488 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
2 locks held by syz.7.25/6919:
#0: ffff88803549db28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x253/0x320 fs/file.c:1232
#1: ffff88805bb5e488 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline]
#1: ffff88805bb5e488 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
2 locks held by syz.8.26/6957:
#0: ffff888029ef4728 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x253/0x320 fs/file.c:1232
#1: ffff88803aff8488 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline]
#1: ffff88803aff8488 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
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: 3610 Comm: kworker/u8:14 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__preempt_count_add kernel/rcu/tree.c:747 [inline]
RIP: 0010:rcu_is_watching+0x8/0xb0 kernel/rcu/tree.c:750
Code: 2d 4a 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 70 28 51 10 e8 1b f3 51 09 89 c3 83 f8 08 73 65 49 bf
RSP: 0018:ffffc9000de476a8 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81c613a8
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8f1d6030
RBP: ffffc9000de47770 R08: ffffffff8f1d6037 R09: 1ffffffff1e3ac06
R10: dffffc0000000000 R11: fffffbfff1e3ac07 R12: dffffc0000000000
R13: ffffc9000de477c8 R14: ffff8880b8823d38 R15: 1ffff92001bc8edc
FS: 0000000000000000(0000) GS:ffff8881268bc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005605b407e820 CR3: 000000000d7a6000 CR4: 00000000003526f0
Call Trace:
trace_irq_enable+0x37/0x110 include/trace/events/preemptirq.h:40
trace_hardirqs_on+0x18/0x40 kernel/trace/trace_preemptirq.c:73
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
_raw_spin_unlock_irqrestore+0x85/0x110 kernel/locking/spinlock.c:194
raw_spin_unlock_irqrestore_wake include/linux/sched/wake_q.h:94 [inline]
rtlock_slowlock kernel/locking/rtmutex.c:1896 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x167/0x2c0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
__local_bh_disable_ip+0x264/0x400 kernel/softirq.c:168
local_bh_disable include/linux/bottom_half.h:20 [inline]
spin_lock_bh include/linux/spinlock_rt.h:87 [inline]
batadv_nc_purge_paths+0xf7/0x3f0 net/batman-adv/network-coding.c:442
batadv_nc_worker+0x87e/0xbc0 net/batman-adv/network-coding.c:720
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245