INFO: task syz.1.54:6291 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.54 state:D stack:25096 pid:6291 tgid:6285 ppid:5799 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
percpu_rwsem_wait+0x2e6/0x330 kernel/locking/percpu-rwsem.c:164
__percpu_down_read+0xfc/0x140 kernel/locking/percpu-rwsem.c:180
percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs.h:1916 [inline]
sb_start_write+0x18e/0x1c0 include/linux/fs.h:2052
mnt_want_write+0x41/0x90 fs/namespace.c:508
open_last_lookups fs/namei.c:3884 [inline]
path_openat+0x869/0x3840 fs/namei.c:4131
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f82ffeaeec9
RSP: 002b:00007f82fe0f5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f8300106090 RCX: 00007f82ffeaeec9
RDX: 0000000000000042 RSI: 0000200000001000 RDI: ffffffffffffff9c
RBP: 00007f82fff31f91 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000001ff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8300106128 R14: 00007f8300106090 R15: 00007ffe2a086388
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d7aa500 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d7aa500 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d7aa500 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:5/70:
3 locks held by kworker/u8:7/1159:
6 locks held by kworker/u8:10/3567:
2 locks held by dhcpcd/5460:
#0: ffffffff8ea5bd98 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x5f1/0x790 net/socket.c:1337
#1: ffffffff8ea77938 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xd0/0x650 net/8021q/vlan.c:577
2 locks held by getty/5561:
#0: ffff88823bf6a8a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz.1.54/6291:
#0: ffff888038d54480 (sb_writers#25){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508
4 locks held by syz-executor/6426:
1 lock held by syz-executor/7072:
#0: ffffffff8ea77938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ea77938 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978
4 locks held by syz-executor/7163:
#0: ffff8880108c4480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3111 [inline]
#0: ffff8880108c4480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff8880237b2478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff88802757ab48 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802757ab48 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8e309778 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184
7 locks held by syz-executor/7164:
#0: ffff8880108c4480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3111 [inline]
#0: ffff8880108c4480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff88805ea0fc78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff88802757ac38 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802757ac38 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8e309778 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
#4: ffff88805ce650d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff88805ce650d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
#4: ffff88805ce650d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294
#5: ffff88805ce60300 (&devlink->lock_key#13){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1721
#6: ffffffff8ea77938 (rtnl_mutex){+.+.}-{4:4}, at: unregister_nexthop_notifier+0x17/0x40 net/ipv4/nexthop.c:3999
2 locks held by syz-executor/7241:
#0: ffffffff8e202c00 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e202c00 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e202c00 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8ea77938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8ea77938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8ea77938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064
=============================================
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 10/02/2025
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:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4b9/0x870 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: 3567 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: bat_events batadv_dat_purge
RIP: 0010:mark_held_locks kernel/locking/lockdep.c:4313 [inline]
RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:4343 [inline]
RIP: 0010:lockdep_hardirqs_on_prepare+0xf3/0x2a0 kernel/locking/lockdep.c:4410
Code: 10 83 bb 58 0b 00 00 00 0f 8e d1 00 00 00 49 89 de 49 81 c6 60 0b 00 00 45 31 ff 4d 89 f4 eb 13 49 ff c7 48 63 83 58 0b 00 00 <49> 83 c4 28 49 39 c7 7d 44 49 83 ff 31 73 2d 41 8b 44 24 20 a9 00
RSP: 0018:ffffc9000d8c7800 EFLAGS: 00000002
RAX: 0000000000000004 RBX: ffff8880312c1e00 RCX: ffffffff9276e1c8
RDX: 0000000000000002 RSI: ffff8880312c2988 RDI: ffff8880312c1e00
RBP: ffffc9000d8c78d0 R08: ffffffff8ef76777 R09: 1ffffffff1deecee
R10: dffffc0000000000 R11: fffffbfff1deecef R12: ffff8880312c2988
R13: ffff888055f13400 R14: ffff8880312c2960 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff888126bcb000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8af1b21000 CR3: 0000000028fb6000 CR4: 00000000003526f0
Call Trace:
trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
_raw_spin_unlock_irqrestore+0x85/0x110 kernel/locking/spinlock.c:194
unlock_rt_mutex_safe kernel/locking/rtmutex.c:344 [inline]
rt_mutex_slowunlock+0x493/0x8a0 kernel/locking/rtmutex.c:1454
spin_unlock_bh include/linux/spinlock_rt.h:110 [inline]
__batadv_dat_purge+0x335/0x400 net/batman-adv/distributed-arp-table.c:185
batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:204
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4b9/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245