INFO: task syz.0.6981:22659 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.6981 state:D stack:26696 pid:22659 tgid:22658 ppid:5854 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]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339
rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
rt_mutex_slowlock+0x2b1/0x6e0 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline]
mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547
bdev_open+0xe0/0xcc0 block/bdev.c:945
blkdev_open+0x46c/0x610 block/fops.c:694
do_dentry_open+0x9ae/0x1350 fs/open.c:965
vfs_open+0x3b/0x350 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2ef1/0x3840 fs/namei.c:4046
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
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: 0033:0x7f65fc17d550
RSP: 002b:00007f65fa3e5b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f65fc17d550
RDX: 0000000000000000 RSI: 00007f65fa3e5c10 RDI: 00000000ffffff9c
RBP: 00007f65fa3e5c10 R08: 0000000000000000 R09: 002364626e2f7665
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f65fc3b6038 R14: 00007f65fc3b5fa0 R15: 00007ffff57be208
Showing all locks held in the system:
1 lock held by rcu_tasks_trace/36:
#0: ffffffff8d9a98c0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{4:4}, at: rcu_tasks_one_gp+0xaf9/0xdf0 kernel/rcu/tasks.h:614
1 lock held by khungtaskd/39:
#0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
6 locks held by kworker/u8:5/70:
2 locks held by getty/5599:
#0: ffff88823bf6a0a0 (&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
1 lock held by udevd/12066:
#0: ffff888024e614c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:945
1 lock held by syz.0.6981/22659:
#0: ffff888024e614c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:945
1 lock held by syz.5.7912/24788:
#0: ffff888024e614c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288
2 locks held by kworker/u8:38/25920:
#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: ffffc90003ee7bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90003ee7bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
2 locks held by kworker/u8:45/25928:
4 locks held by syz.1.8511/26231:
1 lock held by syz.8.8516/26244:
1 lock held by syz.4.8518/26247:
#0: ffff88808b908d90 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline]
#0: ffff88808b908d90 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x214/0x4d0 mm/util.c:578
2 locks held by syz.4.8518/26248:
2 locks held by modprobe/26250:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 25928 Comm: kworker/u8:45 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4868 [inline]
RIP: 0010:__lock_acquire+0x44c/0xd20 kernel/locking/lockdep.c:5187
Code: 0f 44 ea 44 8b a7 18 0b 00 00 41 8d 4c 24 ff 83 f9 ff bd ff ff ff ff 0f 4c e9 ff c5 45 8d 7c 24 01 49 ff cc 44 89 f9 83 c1 fe <78> 44 44 89 e3 81 e3 ff ff ff 7f 83 f9 31 73 1d 48 8d 0c 9b 8b 8c
RSP: 0018:ffffc90003c07650 EFLAGS: 00000017
RAX: 000000000002000b RBX: 0000000000000003 RCX: 0000000000000003
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff88802df00000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8af90c4b
R10: dffffc0000000000 R11: fffffbfff1e3ab47 R12: 0000000000000003
R13: 0000000000000001 R14: ffff88802df00bc0 R15: 0000000000000005
FS: 0000000000000000(0000) GS:ffff8881269bf000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9139afefe8 CR3: 0000000063b34000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
rt_spin_lock+0x1d7/0x2c0 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+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245