INFO: task kworker/R-ipv6_:3197 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/R-ipv6_ state:D stack:25432 pid:3197 tgid:3197 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820 rtnl_net_lock include/linux/rtnetlink.h:130 [inline] addrconf_dad_work+0x11f/0x1360 net/ipv6/addrconf.c:4208 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] rescuer_thread+0x905/0x14a0 kernel/workqueue.c:3621 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by kthreadd/2: 3 locks held by kworker/0:0/9: 4 locks held by kworker/0:1/10: 3 locks held by kworker/u8:0/12: #0: ffff88813fe94140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90000117d08 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff8880556d0780 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6645 [inline] #2: ffff8880556d0780 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0x92/0x570 net/wireless/core.c:499 3 locks held by kworker/u8:1/13: 1 lock held by kworker/R-mm_pe/14: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2787 [inline] #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xb7b/0x14a0 kernel/workqueue.c:3649 2 locks held by kworker/1:0/24: 4 locks held by kworker/1:1/29: #0: ffff888078be6d40 ((wq_completion)wg-kex-wg1#6){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90000a47d08 ((work_completion)(&({ do { const void __seg_gs *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __asm__ ("" : "=r"(__ptr) : "0"((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff88807cb113c0 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x1c2/0x860 drivers/net/wireguard/noise.c:598 #3: ffff888078712ad0 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x5ac/0x860 drivers/net/wireguard/noise.c:632 1 lock held by khungtaskd/31: #0: ffffffff8e7e5560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e7e5560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e7e5560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 1 lock held by kworker/R-write/33: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2729 3 locks held by kworker/u8:2/36: 3 locks held by kworker/u8:3/48: 5 locks held by kworker/u9:0/50: #0: ffff88807ad88140 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90000bb7d08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff888033414ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331 #3: ffff8880334140b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x141/0xb20 net/bluetooth/hci_sync.c:5764 #4: ffffffff9088af00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff9088af00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x119/0x360 net/bluetooth/hci_conn.c:1411 3 locks held by kworker/u8:4/57: 3 locks held by kworker/u8:5/66: 4 locks held by kworker/u8:6/329: 3 locks held by kworker/0:2/804: 3 locks held by kworker/u8:7/1113: 3 locks held by kworker/u8:8/1116: 4 locks held by kworker/u8:9/1163: 4 locks held by kworker/0:3/1221: 3 locks held by kworker/1:2/2170: #0: ffff88813fe57140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc9000791fd08 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffffffff90603e60 (rtnl_mutex){+.+.}-{4:4}, at: regdb_fw_cb.cold+0x22/0x7a net/wireless/reg.c:1005 1 lock held by kworker/R-mld/3196: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2787 [inline] #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xb7b/0x14a0 kernel/workqueue.c:3649 3 locks held by kworker/R-ipv6_/3197: #0: ffff8880337e6940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc9000e1f7c70 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffffffff90603e60 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff90603e60 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11f/0x1360 net/ipv6/addrconf.c:4208 5 locks held by kworker/R-bat_e/3231: 3 locks held by kworker/u8:10/3401: 1 lock held by kworker/R-ext4-/4949: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2729 2 locks held by udevd/4986: 1 lock held by dhcpcd/5281: #0: ffffffff90603e60 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff90603e60 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff90603e60 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8bb/0x2380 net/core/rtnetlink.c:4109 4 locks held by kworker/1:3/5352: 2 locks held by getty/5374: #0: ffff8880380b70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5610: 1 lock held by syz-executor/5616: 1 lock held by syz-executor/5617: 5 locks held by kworker/u9:3/5620: #0: ffff8880747fd940 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90003dbfd08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff8880724ecea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331 #3: ffff8880724ec0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x141/0xb20 net/bluetooth/hci_sync.c:5764 #4: ffffffff9088af00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff9088af00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x119/0x360 net/bluetooth/hci_conn.c:1411 7 locks held by kworker/u9:4/5624: #0: ffff88807b2fe140 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90003defd08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff888033410ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331 #3: ffff8880334100b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x141/0xb20 net/bluetooth/hci_sync.c:5764 #4: ffffffff9088af00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff9088af00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x119/0x360 net/bluetooth/hci_conn.c:1411 #5: ffff88807b67faf8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x95/0x710 net/bluetooth/l2cap_core.c:1779 #6: ffffffff8e7f10a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 3 locks held by kworker/0:4/5625: #0: ffff88813fe55d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90003dffd08 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffffffff90603e60 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x91/0x13a0 net/wireless/reg.c:2466 5 locks held by syz-executor/5626: 4 locks held by udevd/5631: #0: ffff888079fa5878 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff88803357ec80 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888078ab15a8 (kn->active#31){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888078ab15a8 (kn->active#31){.+.+}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff8880345281d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline] #3: ffff8880345281d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 5 locks held by kworker/u9:6/5633: #0: ffff88807b2fb940 ((wq_completion)hci4){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90003e6fd08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff88805d63cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331 #3: ffff88805d63c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x141/0xb20 net/bluetooth/hci_sync.c:5764 #4: ffffffff9088af00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff9088af00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x119/0x360 net/bluetooth/hci_conn.c:1411 5 locks held by kworker/u9:9/5636: #0: ffff88807ad8d940 ((wq_completion)hci3){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90003e9fd08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff8880724f0ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331 #3: ffff8880724f00b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x141/0xb20 net/bluetooth/hci_sync.c:5764 #4: ffffffff9088af00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff9088af00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x119/0x360 net/bluetooth/hci_conn.c:1411 1 lock held by kworker/R-wg-cr/5698: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2787 [inline] #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xb7b/0x14a0 kernel/workqueue.c:3649 1 lock held by kworker/R-wg-cr/5700: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2729 1 lock held by kworker/R-wg-cr/5701: 1 lock held by kworker/R-wg-cr/5702: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2787 [inline] #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xb7b/0x14a0 kernel/workqueue.c:3649 1 lock held by kworker/R-wg-cr/5703: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2787 [inline] #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xb7b/0x14a0 kernel/workqueue.c:3649 1 lock held by kworker/R-wg-cr/5704: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2787 [inline] #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xb7b/0x14a0 kernel/workqueue.c:3649 1 lock held by kworker/R-wg-cr/5705: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2729 1 lock held by kworker/R-wg-cr/5706: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2787 [inline] #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xb7b/0x14a0 kernel/workqueue.c:3649 1 lock held by kworker/R-wg-cr/5707: 1 lock held by kworker/R-wg-cr/5708: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2787 [inline] #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xb7b/0x14a0 kernel/workqueue.c:3649 1 lock held by kworker/R-wg-cr/5709: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2787 [inline] #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xb7b/0x14a0 kernel/workqueue.c:3649 1 lock held by kworker/R-wg-cr/5710: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2787 [inline] #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xb7b/0x14a0 kernel/workqueue.c:3649 1 lock held by kworker/R-wg-cr/5711: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2787 [inline] #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xb7b/0x14a0 kernel/workqueue.c:3649 1 lock held by kworker/R-wg-cr/5712: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2787 [inline] #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xb7b/0x14a0 kernel/workqueue.c:3649 3 locks held by kworker/1:4/5713: 2 locks held by kworker/1:5/5726: 4 locks held by kworker/1:6/5739: #0: ffff888033fd8d40 ((wq_completion)wg-kex-wg0#8){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc9000469fd08 ((work_completion)(&({ do { const void __seg_gs *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __asm__ ("" : "=r"(__ptr) : "0"((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff888022e813c0 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x1c2/0x860 drivers/net/wireguard/noise.c:598 #3: ffff8880569ff028 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x666/0x860 drivers/net/wireguard/noise.c:643 3 locks held by kworker/1:7/5740: 1 lock held by kworker/0:5/5747: #0: ffffffff8e692860 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2729 8 locks held by kworker/0:6/5748: 5 locks held by kworker/0:7/5778: 2 locks held by syz.1.2/5814: 4 locks held by kworker/0:8/5815: 4 locks held by kworker/0:9/5817: 2 locks held by syz.3.9/5838: #0: ffff8880355110a0 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline] #0: ffff8880355110a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:352 [inline] #0: ffff8880355110a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline] #0: ffff8880355110a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0x256/0x2f0 drivers/tty/tty_ldisc.c:780 #1: ffffffff90603e60 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff90603e60 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2162 3 locks held by kworker/u8:11/5855: 4 locks held by kworker/u8:12/5856: 4 locks held by kworker/u8:13/5857: 8 locks held by kworker/u8:14/5858: 4 locks held by kworker/u8:15/5859: 4 locks held by kworker/u8:16/5860: 4 locks held by kworker/u8:17/5861: #0: ffff88813fe94140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc9000502fd08 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff8880554f0780 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6645 [inline] #2: ffff8880554f0780 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0x92/0x570 net/wireless/core.c:499 #3: ffffffff8e7f10a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311 ============================================= 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 05/09/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 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: 3231 Comm: kworker/R-bat_e Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: bat_events batadv_dat_purge RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:124 [inline] RIP: 0010:lock_acquire kernel/locking/lockdep.c:5844 [inline] RIP: 0010:lock_acquire+0x147/0x370 kernel/locking/lockdep.c:5825 Code: 48 8b 74 24 68 48 89 ef e8 d6 e3 91 00 8b 0d b4 bf f2 0e 85 c9 0f 84 bd 00 00 00 65 8b 05 49 4a 25 12 85 c0 0f 85 ae 00 00 00 <65> 48 8b 05 c9 02 25 12 8b 90 8c 0b 00 00 85 d2 0f 85 98 00 00 00 RSP: 0018:ffffc90000a07eb0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff81b7cec1 RDI: fffffbfff1cfcaac RBP: ffffffff8e7e5560 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000200 R11: 0000000000017666 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124487000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7998e23388 CR3: 000000000e596000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4570 [inline] slab_alloc_node mm/slub.c:4899 [inline] kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4906 skb_clone+0x190/0x400 net/core/skbuff.c:2107 deliver_clone net/bridge/br_forward.c:125 [inline] br_flood+0x35c/0x650 net/bridge/br_forward.c:250 br_handle_frame_finish+0xff4/0x1f60 net/bridge/br_input.c:229 br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1165 br_nf_pre_routing_finish_ipv6+0x659/0xdd0 net/bridge/br_netfilter_ipv6.c:153 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x39c/0x8b0 net/bridge/br_netfilter_ipv6.c:183 br_nf_pre_routing+0x90f/0x1560 net/bridge/br_netfilter_hooks.c:513 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0xcdd/0x1520 net/bridge/br_input.c:442 __netif_receive_skb_core.constprop.0+0x6c5/0x3530 net/core/dev.c:6089 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6200 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6315 process_backlog+0x37a/0x1580 net/core/dev.c:6666 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7733 napi_poll net/core/dev.c:7796 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:7953 handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xac/0xe0 kernel/softirq.c:510 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] __batadv_dat_purge.part.0+0x294/0x3c0 net/batman-adv/distributed-arp-table.c:185 __batadv_dat_purge net/batman-adv/distributed-arp-table.c:166 [inline] batadv_dat_purge+0x4b/0xa0 net/batman-adv/distributed-arp-table.c:204 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] rescuer_thread+0x905/0x14a0 kernel/workqueue.c:3621 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245