INFO: task syz.3.2307:14685 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.2307      state:D stack:26904 pid:14685 tgid:14684 ppid:5862   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760
 bdev_open+0x41a/0xe40 block/bdev.c:945
 blkdev_open+0x34e/0x4f0 block/fops.c:694
 do_dentry_open+0x97f/0x1530 fs/open.c:965
 vfs_open+0x82/0x3f0 fs/open.c:1095
 do_open fs/namei.c:3887 [inline]
 path_openat+0x1de4/0x2cb0 fs/namei.c:4046
 do_filp_open+0x20b/0x470 fs/namei.c:4073
 do_sys_openat2+0x11b/0x1d0 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+0x174/0x210 fs/open.c:1461
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9a3158d510
RSP: 002b:00007f9a3238eb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000028000 RCX: 00007f9a3158d510
RDX: 0000000000028000 RSI: 00007f9a3238ec10 RDI: 00000000ffffff9c
RBP: 00007f9a3238ec10 R08: 0000000000000000 R09: 002364626e2f7665
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f9a317d6038 R14: 00007f9a317d5fa0 R15: 00007ffef54a3c18
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
6 locks held by kworker/1:2/1587:
 #0: ffff888021a99948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
 #1: ffffc90004cafd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
 #2: ffff888145773198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #2: ffff888145773198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898
 #3: ffff888032e6c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #3: ffff888032e6c198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
 #4: ffff88804b427160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #4: ffff88804b427160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
 #5: ffffffff8e4756d0 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xa9/0x250 kernel/umh.c:214
2 locks held by getty/5609:
 #0: ffff88814d6960a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
3 locks held by kworker/0:6/5926:
 #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
 #1: ffffc9000463fd10 ((work_completion)(&pool->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
 #2: ffffffff90385148 (rtnl_mutex){+.+.}-{4:4}, at: xp_release_deferred+0x22/0x1f0 net/xdp/xsk_buff_pool.c:288
2 locks held by kworker/u8:28/9356:
 #0: ffff8880b843a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:644 [inline]
 #0: ffff8880b843a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:629
 #1: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #1: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #1: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2256 [inline]
 #1: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x1d5/0x5b0 kernel/trace/bpf_trace.c:2300
1 lock held by udevd/14460:
 #0: ffff8880267fc358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945
1 lock held by syz.3.2307/14685:
 #0: ffff8880267fc358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945
7 locks held by kworker/0:0/15413:
 #0: ffff888021a99948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
 #1: ffffc90003437d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
 #2: ffff88814573c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #2: ffff88814573c198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898
 #3: ffff88804ccbe198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #3: ffff88804ccbe198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9c0 drivers/usb/core/hub.c:2335
 #4: ffff8880341f9160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #4: ffff8880341f9160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
 #4: ffff8880341f9160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1294
 #5: ffffffff8fb98ec8 (input_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:228 [inline]
 #5: ffffffff8fb98ec8 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x184/0x4d0 drivers/input/input.c:2221
 #6: ffffffff8e5ccb38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by syz.1.2827/16663:
 #0: ffffffff90385148 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
 #0: ffffffff90385148 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3433
2 locks held by syz.4.2830/16690:
 #0: ffff88807de9f070 (&usblp->wmut){+.+.}-{4:4}, at: usblp_write+0x6b/0x8f0 drivers/usb/class/usblp.c:751
 #1: ffff88807de9f100 (&usblp->mut){+.+.}-{4:4}, at: usblp_wwait+0x600/0x920 drivers/usb/class/usblp.c:934
2 locks held by syz.4.2830/16691:
 #0: ffffffff8f6e0800 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
 #0: ffffffff8f6e0800 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
 #0: ffffffff8f6e0800 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x113/0x2c0 net/core/rtnetlink.c:574
 #1: ffffffff90385148 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff90385148 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff90385148 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4056
1 lock held by syz.4.2830/16692:
 #0: ffffffff90385148 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff90385148 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newroute+0xfa/0x210 net/ipv4/fib_frontend.c:921
1 lock held by syz.0.2831/16674:
 #0: ffffffff90385148 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
 #0: ffffffff90385148 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3433
1 lock held by syz.2.2833/16687:
3 locks held by syz.2.2833/16688:
 #0: ffffffff90385148 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff90385148 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x371/0xe90 net/core/rtnetlink.c:6952
 #1: ffff8880792ced30 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2761 [inline]
 #1: ffff8880792ced30 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
 #1: ffff8880792ced30 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:39 [inline]
 #1: ffff8880792ced30 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: tc_modify_qdisc+0x2df/0x2170 net/sched/sch_api.c:1811
 #2: ffffffff8e5ccb38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by dhcpcd/16693:
 #0: ffff88807b5e4258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1669 [inline]
 #0: ffff88807b5e4258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3251
1 lock held by dhcpcd/16694:
 #0: ffff888046c70258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1669 [inline]
 #0: ffff888046c70258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3251

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/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+0xf0e/0x1260 kernel/hung_task.c:491
 kthread+0x3c2/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 16691 Comm: syz.4.2830 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:lock_acquire kernel/locking/lockdep.c:5868 [inline]
RIP: 0010:lock_acquire+0x16a/0x350 kernel/locking/lockdep.c:5825
Code: 45 89 e0 89 e9 44 89 ea 65 ff 05 59 37 3f 12 48 81 24 24 00 02 00 00 44 89 f6 48 89 df 6a 00 6a 00 6a 00 ff b4 24 88 00 00 00 <41> 0f 94 c1 41 57 45 0f b6 c9 e8 e7 d8 ff ff 48 c7 c7 d8 d6 e2 8d
RSP: 0018:ffffc90000a08b58 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffffffff8e5c15a0 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e5c15a0
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff90ab7397 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f638d9f66c0(0000) GS:ffff8881247b3000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559297efe168 CR3: 0000000030138000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 select_task_rq_fair+0x383/0x45e0 kernel/sched/fair.c:8505
 select_task_rq kernel/sched/core.c:3607 [inline]
 try_to_wake_up+0x583/0x1870 kernel/sched/core.c:4316
 hrtimer_wakeup+0x47/0x60 kernel/time/hrtimer.c:1997
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1056
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline]
RIP: 0010:vprintk_emit+0x567/0x6d0 kernel/printk/printk.c:2449
Code: 00 4d 85 ed 0f 85 19 01 00 00 e8 c4 be 20 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 22 ba 20 00 48 85 ed 0f 85 25 01 00 00 <e8> a4 be 20 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00
RSP: 0018:ffffc9001bea7170 EFLAGS: 00000283
RAX: 00000000000586c7 RBX: 0000000000000031 RCX: ffffc9000ed91000
RDX: 0000000000080000 RSI: ffffffff819ae146 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff920037d4e30
R13: 0000000000000200 R14: ffff88801eaac880 R15: ffffc9001bea7238
 _printk+0xc7/0x100 kernel/printk/printk.c:2475
 batadv_hardif_activate_interface.part.0+0x139/0x350 net/batman-adv/hard-interface.c:669
 batadv_hardif_activate_interface net/batman-adv/hard-interface.c:654 [inline]
 batadv_hardif_enable_interface+0x9ec/0xd50 net/batman-adv/hard-interface.c:765
 batadv_meshif_slave_add+0x10f/0x130 net/batman-adv/mesh-interface.c:845
 do_set_master+0x40c/0x730 net/core/rtnetlink.c:2948
 rtnl_newlink_create net/core/rtnetlink.c:3839 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3942 [inline]
 rtnl_newlink+0xd63/0x2000 net/core/rtnetlink.c:4057
 rtnetlink_rcv_msg+0x95b/0xe90 net/core/rtnetlink.c:6946
 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg net/socket.c:729 [inline]
 ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
 __sys_sendmsg+0x16d/0x220 net/socket.c:2700
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f638f78eba9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f638d9f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f638f9d6180 RCX: 00007f638f78eba9
RDX: 0000000000004054 RSI: 00002000000002c0 RDI: 000000000000000c
RBP: 00007f638f811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f638f9d6218 R14: 00007f638f9d6180 R15: 00007ffde1f5ccb8
 </TASK>