INFO: task syz.3.814:8862 blocked for more than 143 seconds. Not tainted 6.1.134-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.814 state:D stack:28616 pid:8862 ppid:4254 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6561 schedule+0xbf/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 rwsem_down_read_slowpath kernel/locking/rwsem.c:1094 [inline] __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x6ff/0xa30 kernel/locking/rwsem.c:1522 iterate_supers+0xac/0x1e0 fs/super.c:755 ksys_sync+0xb9/0x1c0 fs/sync.c:102 __do_sys_sync+0xa/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f6b2018e169 RSP: 002b:00007f6b1ffff038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f6b203b5fa0 RCX: 00007f6b2018e169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f6b203b5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f6b203b5fa0 R15: 00007ffdb0de9d98 Showing all locks held in the system: 2 locks held by kworker/u4:0/9: #0: ffff888017c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffff8880b8e27788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x419/0x790 kernel/sched/psi.c:999 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32e910 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d32f110 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 2 locks held by kworker/0:1/14: #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc90000137d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 3 locks held by kworker/1:0/22: #0: ffff88814c8d8d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc900001c7d20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #2: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16e0 net/ipv6/addrconf.c:4134 1 lock held by khungtaskd/28: #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510 2 locks held by dhcpcd/3916: #0: ffffffff8e536768 (vlan_ioctl_mutex){+.+.}-{3:3}, at: sock_ioctl+0x526/0x770 net/socket.c:1283 #1: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: vlan_ioctl_handler+0x114/0x980 net/8021q/vlan.c:554 2 locks held by getty/4005: #0: ffff888030fc3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x54a/0x1620 drivers/tty/n_tty.c:2198 2 locks held by kworker/u4:11/4426: #0: ffff888017c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffff8880b8f27788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x419/0x790 kernel/sched/psi.c:999 4 locks held by kworker/0:12/4753: #0: ffff8880b8e3a998 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa8/0x140 kernel/sched/core.c:545 #1: ffffc9000600fd20 ((work_completion)(&(&ssp->work)->work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #2: ffff8880b8e43c58 (&ACCESS_PRIVATE(sdp, lock)){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] #2: ffff8880b8e43c58 (&ACCESS_PRIVATE(sdp, lock)){..-.}-{2:2}, at: srcu_invoke_callbacks+0x2f7/0x460 kernel/rcu/srcutree.c:1605 #3: ffff888017ff0a18 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xad/0x1250 kernel/sched/core.c:4111 2 locks held by kworker/0:15/4757: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc9000becfd20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 3 locks held by kworker/0:16/4758: #0: ffff88814c8d8d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc9000bedfd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #2: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16e0 net/ipv6/addrconf.c:4134 1 lock held by syz-executor/5948: #0: ffff88807ca020e0 (&type->s_umount_key#115){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 2 locks held by syz-executor/6956: #0: ffff888044b360e0 (&type->s_umount_key#78){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 #1: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #1: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962 1 lock held by syz.3.814/8862: #0: ffff88807ca020e0 (&type->s_umount_key#115){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755 3 locks held by syz-executor/10425: #0: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7cb/0x1000 net/core/rtnetlink.c:6150 #1: ffff88805a4813e8 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_open+0x229/0x410 drivers/net/wireguard/device.c:49 #2: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #2: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.134-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1ca/0x430 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf88/0xfd0 kernel/hung_task.c:377 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7719 Comm: kworker/u4:21 Not tainted 6.1.134-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:validate_chain+0x57/0x5950 kernel/locking/lockdep.c:3781 Code: 48 89 84 24 60 02 00 00 49 bc 00 00 00 00 00 fc ff df 48 c7 84 24 00 01 00 00 b3 8a b5 41 48 c7 84 24 08 01 00 00 bd 8d ba 8c <48> c7 84 24 10 01 00 00 60 22 6b 81 48 8d 8c 24 00 01 00 00 48 c1 RSP: 0018:ffffc9001ca77680 EFLAGS: 00000082 RAX: 9266725991151b00 RBX: ffffffff90c42260 RCX: ec30b245696e6cc3 RDX: 0000000000000000 RSI: ffff8880311228f0 RDI: ffff888031121dc0 RBP: ffffc9001ca77930 R08: dffffc0000000000 R09: fffffbfff225704d R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: ffff888031121dc0 R14: ec30b245696e6cc3 R15: 1ffff11006224522 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ac90d80000 CR3: 000000000d08e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] batadv_nc_process_nc_paths+0xd6/0x390 net/batman-adv/network-coding.c:687 batadv_nc_worker+0x528/0x610 net/batman-adv/network-coding.c:735 process_one_work+0x917/0x1260 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295