INFO: task syz.7.52:6541 blocked for more than 184 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.52 state:D stack:27096 pid:6541 tgid:6534 ppid:5979 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 do_uevent+0x2c3/0x570 fs/dlm/lockspace.c:206 new_lockspace fs/dlm/lockspace.c:583 [inline] __dlm_new_lockspace+0x1aa4/0x2060 fs/dlm/lockspace.c:638 device_create_lockspace+0xc7/0x350 fs/dlm/user.c:414 device_write+0x875/0xed0 fs/dlm/user.c:606 vfs_write+0x29f/0xbb0 fs/read_write.c:685 ksys_write+0x156/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc9d37de019 RSP: 002b:00007fc9d1a15028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc9d3a66090 RCX: 00007fc9d37de019 RDX: 0000000000000078 RSI: 0000200000000400 RDI: 0000000000000007 RBP: 00007fc9d387500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc9d3a66128 R14: 00007fc9d3a66090 R15: 00007ffd61680c38 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: #0: ffff8880330db138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff8880330db138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90000117c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90000117c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x123/0x16e0 net/ipv6/addrconf.c:4229 1 lock held by khungtaskd/38: #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 5 locks held by kworker/u8:7/157: #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90003897c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90003897c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5a39e0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673 #3: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1711 #4: ffff888036a908d8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6884 [inline] #4: ffff888036a908d8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_leave+0x178/0x200 net/wireless/core.c:1574 2 locks held by dhcpcd/5259: #0: ffff888039b8e928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe7/0xee0 net/netlink/af_netlink.c:2273 #1: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dump_ifinfo+0xa74/0x14b0 net/core/rtnetlink.c:2562 2 locks held by getty/5353: #0: ffff888036c930a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900040142e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 6 locks held by kworker/u8:26/5875: 1 lock held by syz.7.52/6541: #0: ffffffff99bcb458 (&ls_lock){+.+.}-{4:4}, at: __dlm_new_lockspace+0xa3/0x2060 fs/dlm/lockspace.c:632 1 lock held by dlm_recoverd/6548: #0: ffff888039224d20 (&ls->ls_in_recovery){+.+.}-{4:4}, at: dlm_recoverd+0xba/0x23e0 fs/dlm/recoverd.c:400 1 lock held by syz.3.246/8174: #0: ffffffff99bcb458 (&ls_lock){+.+.}-{4:4}, at: __dlm_new_lockspace+0xa3/0x2060 fs/dlm/lockspace.c:632 2 locks held by syz-executor/8643: #0: ffffffff8f5a39e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4e2/0x720 net/core/net_namespace.c:575 #1: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #1: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x60 net/core/dev.c:11559 1 lock held by syz-executor/8648: #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 1 lock held by syz-executor/8649: #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 2 locks held by syz-executor/8650: #0: ffffffff8fafc538 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8fafc538 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8fafc538 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 6 locks held by syz-executor/8735: #0: ffffffff8f5a39e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4e2/0x720 net/core/net_namespace.c:575 #1: ffffffff8f2fee00 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1189 #2: ffffffff8f2ff040 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1194 #3: ffff8880846a51c8 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xf0/0x650 drivers/infiniband/core/device.c:953 #4: ffff8880846a54e8 (&rxe->usdev_lock){+.+.}-{4:4}, at: rxe_query_port+0x7e/0x3d0 drivers/infiniband/sw/rxe/rxe_verbs.c:55 #5: ffffffff8f5b2578 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x173/0x7f0 drivers/infiniband/core/verbs.c:2051 ============================================= 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 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 5875 Comm: kworker/u8:26 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: bat_events batadv_dat_purge RIP: 0010:debug_lockdep_rcu_enabled+0x20/0x40 kernel/rcu/update.c:321 Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d a3 a9 6b 04 00 74 1d 83 3d ba bb 6b 04 00 74 14 65 48 8b 0d 38 25 5a 07 <31> c0 83 b9 04 0c 00 00 00 0f 94 c0 e9 7f c5 03 00 cc cc cc cc cc RSP: 0018:ffffc9000be37a30 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffffff8188721c RCX: ffff88802ae41f00 RDX: 0000000024b63f9e RSI: ffffffff8daf6c22 RDI: ffffffff8bca7880 RBP: 0000000000000200 R08: ffffffff8188721c R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8e1c3000 R12: ffff88802ae42af4 R13: dffffc0000000000 R14: 1ffff110055c855e R15: ffff88802ae423c0 FS: 0000000000000000(0000) GS:ffff888125c3e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd55cf0fb0 CR3: 000000005f66e000 CR4: 00000000003526f0 Call Trace: rcu_read_lock include/linux/rcupdate.h:841 [inline] __local_bh_disable_ip+0x20e/0x420 kernel/softirq.c:174 local_bh_disable include/linux/bottom_half.h:20 [inline] spin_lock_bh include/linux/spinlock_rt.h:89 [inline] __batadv_dat_purge+0x124/0x400 net/batman-adv/distributed-arp-table.c:174 batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:205 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245