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:28016 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 1 lock held by dhcpcd/3854: #0: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x256/0x1ba0 net/ipv4/devinet.c:1076 2 locks held by getty/3944: #0: ffff88814c781098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 4 locks held by kworker/u4:11/6185: 3 locks held by kworker/u4:20/7156: #0: ffff888017879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc900044bfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251 1 lock held by syz-executor/8827: #0: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3454 3 locks held by kworker/1:9/10278: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90002e6fd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74 3 locks held by kworker/1:24/12307: #0: ffff88802c128538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc900031afd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1530 net/ipv6/addrconf.c:4128 3 locks held by kworker/0:28/23183: #0: ffff88802c128538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000353fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1530 net/ipv6/addrconf.c:4128 2 locks held by kworker/0:30/23185: #0: ffff888017872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000364fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 1 lock held by syz.9.3503/24909: 2 locks held by syz.6.3507/24931: #0: ffffffff8e260ad0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x324/0x5b0 net/core/net_namespace.c:499 #1: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: cfg802154_pernet_exit+0x14/0xc0 net/ieee802154/core.c:324 1 lock held by syz.8.3529/25072: #0: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3f3/0x1f30 drivers/net/tun.c:3066 1 lock held by syz.3.3531/25079: #0: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3f3/0x1f30 drivers/net/tun.c:3066 1 lock held by syz.3.3531/25080: #0: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: ipv6_route_ioctl+0x319/0x500 net/ipv6/route.c:4489 1 lock held by syz.3.3531/25082: #0: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3f3/0x1f30 drivers/net/tun.c:3066 1 lock held by syz-executor/25085: #0: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8e26ca48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x79f/0xf10 net/core/rtnetlink.c:5695 ============================================= 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 11/06/2026 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: 156 Comm: kworker/u4:3 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:memset_erms+0xb/0x10 arch/x86/lib/memset_64.S:65 Code: 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 aa <4c> 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01 RSP: 0018:ffffc90001ff7148 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffc90001ff71e8 RCX: 0000000000000000 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90001ff7248 RBP: dffffc0000000000 R08: ffffc90001ff7247 R09: ffffc90001ff7238 R10: dffffc0000000000 R11: fffff520003fee49 R12: 1ffffffff1ee783c R13: 1ffffffff1ee783c R14: ffffc90001ff721d R15: ffffffff8f73c1e4 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000f9c000 CR3: 00000000721ad000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: unwind_next_frame+0x9e3/0x1cf0 arch/x86/kernel/unwind_orc.c:547 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:612 [inline] kzalloc include/linux/slab.h:738 [inline] cfg80211_inform_single_bss_frame_data net/wireless/scan.c:2533 [inline] cfg80211_inform_bss_frame_data+0x525/0x1ed0 net/wireless/scan.c:2594 ieee80211_bss_info_update+0x6ba/0xa80 net/mac80211/scan.c:190 ieee80211_rx_bss_info net/mac80211/ibss.c:1123 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1614 [inline] ieee80211_ibss_rx_queued_mgmt+0x1763/0x2b50 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