INFO: task rcu_tasks_kthre:11 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:rcu_tasks_kthre state:D stack:27344 pid: 11 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2093 do_wait_for_common+0x295/0x460 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x48/0x60 kernel/sched/completion.c:138 __synchronize_srcu+0x2b5/0x350 kernel/rcu/srcutree.c:930 rcu_tasks_wait_gp+0x43b/0x8e0 kernel/rcu/tasks.h:327 rcu_tasks_kthread+0x2c1/0x640 kernel/rcu/tasks.h:226 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8d11efa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/u4:1/144: 1 lock held by dhcpcd/3850: #0: ffffffff8e24d5c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8e24d5c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x79f/0xf10 net/core/rtnetlink.c:5695 2 locks held by getty/3948: #0: ffff88802d20d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 3 locks held by kworker/0:10/5569: 3 locks held by kworker/0:17/5647: #0: ffff88802be7ad38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000328fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8e24d5c8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1530 net/ipv6/addrconf.c:4128 4 locks held by kworker/u4:8/10180: #0: ffff8880179cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000359fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8e241690 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589 #3: ffffffff8e24d5c8 (rtnl_mutex){+.+.}-{3:3}, at: ieee80211_unregister_hw+0x4d/0x220 net/mac80211/main.c:1393 3 locks held by kworker/u4:12/10255: #0: ffff888017879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc900032efd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8e24d5c8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251 3 locks held by kworker/0:24/24248: 2 locks held by kworker/1:0/26478: #0: ffff888017872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90002427d00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 3 locks held by kworker/1:6/26483: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90002d9fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8d123930 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4c0 kernel/rcu/tree.c:4043 3 locks held by kworker/1:4/6157: #0: ffff88802be7ad38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000368fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8e24d5c8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1530 net/ipv6/addrconf.c:4128 1 lock held by syz-executor/7852: #0: ffffffff8e24d5c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8e24d5c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x79f/0xf10 net/core/rtnetlink.c:5695 2 locks held by syz.5.8027/8037: #0: ffffffff8e241690 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x324/0x5b0 net/core/net_namespace.c:499 #1: ffffffff8e24d5c8 (rtnl_mutex){+.+.}-{3:3}, at: cangw_pernet_exit+0xe/0x20 net/can/gw.c:1279 1 lock held by syz.8.8038/8101: #0: ffff888072469a10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:793 [inline] #0: ffff888072469a10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:650 [inline] #0: ffff888072469a10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x82/0x210 net/socket.c:1346 3 locks held by syz.9.8051/8162: #0: ffffffff8e241690 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x324/0x5b0 net/core/net_namespace.c:499 #1: ffffffff8e24d5c8 (rtnl_mutex){+.+.}-{3:3}, at: vti6_exit_batch_net+0xbb/0x420 net/ipv6/ip6_vti.c:1200 #2: ffffffff8d123a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8d123a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 2 locks held by syz.8.8052/8176: 1 lock held by syz.8.8063/8260: #0: ffffffff8e24d5c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8e24d5c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3454 1 lock held by syz.8.8063/8272: #0: ffffffff8e24d5c8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x256/0x1ba0 net/ipv4/devinet.c:1076 2 locks held by syz.7.8065/8286: #0: ffffffff8d16c808 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 #1: ffffffff8d123a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8d123a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe1b/0xe60 kernel/hung_task.c:369 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10253 Comm: kworker/u4:11 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:check_wait_context kernel/locking/lockdep.c:4786 [inline] RIP: 0010:__lock_acquire+0xab4/0x7d40 kernel/locking/lockdep.c:5070 Code: 45 31 f6 49 81 c6 c8 00 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 e3 00 00 00 41 0f b6 06 84 c0 74 0e 41 0f b6 cd <44> 0f b6 e8 38 c1 44 0f 42 e9 48 8b 44 24 68 42 0f b6 04 00 84 c0 RSP: 0018:ffffc900033274e0 EFLAGS: 00000006 RAX: 0000000000000003 RBX: 0000000000000002 RCX: 0000000000000004 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff91015128 RBP: ffffc90003327728 R08: dffffc0000000000 R09: 1ffffffff2202a25 R10: dffffc0000000000 R11: fffffbfff2202a26 R12: ffff88806487e4a0 R13: ffff88806487d904 R14: ffffffff909a87c8 R15: ffff88806487e4a0 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f547a2c62f8 CR3: 00000000240f7000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x19f/0x400 kernel/locking/lockdep.c:5737 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] ieee80211_vif_get_shift+0x16/0x250 net/mac80211/ieee80211_i.h:1075 ieee80211_sta_get_rates+0xf5/0x6c0 net/mac80211/util.c:2108 ieee80211_update_sta_info net/mac80211/ibss.c:1007 [inline] ieee80211_rx_bss_info net/mac80211/ibss.c:1121 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1614 [inline] ieee80211_ibss_rx_queued_mgmt+0xf79/0x2b50 net/mac80211/ibss.c:1643 ieee80211_iface_process_skb net/mac80211/iface.c:1467 [inline] ieee80211_iface_work+0x714/0xc50 net/mac80211/iface.c:1521 cfg80211_wiphy_work+0x224/0x260 net/wireless/core.c:433 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287