INFO: task syz.1.199:8952 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.199 state:D stack:25448 pid:8952 tgid:8951 ppid:5839 task_flags:0x400140 flags:0x00004006
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
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
kthread_flush_worker+0x1c6/0x240 kernel/kthread.c:1564
__alloc_workqueue+0x146b/0x1b70 kernel/workqueue.c:5763
alloc_workqueue_noprof+0xd4/0x210 kernel/workqueue.c:5786
btrfs_init_workqueues+0x42c/0x6c0 fs/btrfs/disk-io.c:2000
open_ctree+0x11ef/0x3a10 fs/btrfs/disk-io.c:3424
btrfs_fill_super fs/btrfs/super.c:991 [inline]
btrfs_get_tree_super fs/btrfs/super.c:1954 [inline]
btrfs_get_tree_subvol fs/btrfs/super.c:2091 [inline]
btrfs_get_tree+0xf55/0x1820 fs/btrfs/super.c:2125
vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
do_mount fs/namespace.c:4136 [inline]
__do_sys_mount fs/namespace.c:4347 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4324
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: 0033:0x7f6465a403ca
RSP: 002b:00007f6463c9de68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f6463c9def0 RCX: 00007f6465a403ca
RDX: 0000200000000280 RSI: 0000200000005600 RDI: 00007f6463c9deb0
RBP: 0000200000000280 R08: 00007f6463c9def0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000005600
R13: 00007f6463c9deb0 R14: 00000000000055b1 R15: 0000200000000000
Showing all locks held in the system:
5 locks held by kworker/u8:1/13:
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/u8:3/44:
#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: ffffc90000b57bc0 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90000b57bc0 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
2 locks held by kworker/u8:4/67:
3 locks held by kworker/u8:5/1011:
#0: ffff8880634f0938 ((wq_completion)loop5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff8880634f0938 ((wq_completion)loop5){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc900049f7bc0 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc900049f7bc0 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff8880245a1160 (&lo->lo_work_lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:93 [inline]
#2: ffff8880245a1160 (&lo->lo_work_lock){+.+.}-{3:3}, at: loop_process_work+0xf8/0x1060 drivers/block/loop.c:1947
2 locks held by kworker/u8:9/1522:
#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: ffffc90005867bc0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90005867bc0 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
2 locks held by getty/5599:
#0: ffff88823bf900a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222
3 locks held by udevd/5887:
2 locks held by udevd/6517:
#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: __d_lookup+0x66/0x780 fs/dcache.c:2390
#1: ffff88802fc86480 (&lockref->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#1: ffff88802fc86480 (&lockref->lock){+.+.}-{3:3}, at: __d_lookup+0x23e/0x780 fs/dcache.c:2397
1 lock held by syz.1.199/8952:
#0: ffff88805c2840d0 (&type->s_umount_key#51/1){+.+.}-{4:4}, at: alloc_super+0x204/0x990 fs/super.c:345
5 locks held by syz.5.364/11587:
3 locks held by syz.0.366/11610:
2 locks held by syz.3.367/11620:
2 locks held by syz.4.365/11622:
1 lock held by syz.2.368/11624:
=============================================
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+0x436/0x7d0 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: 13 Comm: kworker/u8:1 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:hlock_class kernel/locking/lockdep.c:234 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4879 [inline]
RIP: 0010:__lock_acquire+0x50c/0xd20 kernel/locking/lockdep.c:5187
Code: 49 83 c7 28 41 89 c4 48 39 cb 0f 8d d6 00 00 00 48 83 fb 31 0f 83 92 00 00 00 41 8b 07 25 ff 1f 00 00 48 0f a3 05 e4 e7 61 11 <73> 10 48 69 c0 c8 00 00 00 48 8d 88 f0 f2 9e 92 eb 40 83 3d 8b 77
RSP: 0018:ffffc90000127710 EFLAGS: 00000007
RAX: 00000000000009b7 RBX: 0000000000000001 RCX: 0000000000000002
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff88801ae80000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8184da91
R10: dffffc0000000000 R11: fffffbfff1e3ac47 R12: 00000000ffffff05
R13: 0000000000000001 R14: ffff88801ae80b70 R15: ffff88801ae80b68
FS: 0000000000000000(0000) GS:ffff8881268bc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c367efd CR3: 0000000066122000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__local_bh_disable_ip+0xc3/0x400 kernel/softirq.c:163
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+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245