INFO: task syz.7.5162:19143 blocked for more than 144 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.5162 state:D stack:28032 pid:19143 tgid:19139 ppid:14874 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5402 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7204 __schedule_loop kernel/sched/core.c:7283 [inline] schedule+0x164/0x360 kernel/sched/core.c:7298 cgroup_lock_and_drain_offline+0x516/0x650 kernel/cgroup/cgroup.c:3248 cgroup_kn_lock_live+0x120/0x230 kernel/cgroup/cgroup.c:1699 cgroup_subtree_control_write+0x4b3/0x10a0 kernel/cgroup/cgroup.c:3550 cgroup_file_write+0x331/0x8f0 kernel/cgroup/cgroup.c:4289 kernfs_fop_write_iter+0x3b0/0x540 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x629/0xba0 fs/read_write.c:688 ksys_write+0x156/0x270 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f156358ce59 RSP: 002b:00007f15617bd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f1563806090 RCX: 00007f156358ce59 RDX: 0000000000000006 RSI: 0000200000000080 RDI: 0000000000000005 RBP: 00007f1563622d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1563806128 R14: 00007f1563806090 R15: 00007ffeaa4ad358 Showing all locks held in the system: 4 locks held by rcuc/1/29: #0: ffffffff8de61600 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #1: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #2: ffffffff8dfcace0 (rcu_callback){....}-{0:0}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #2: ffffffff8dfcace0 (rcu_callback){....}-{0:0}, at: rcu_cpu_kthread+0x205/0x1470 kernel/rcu/tree.c:2950 #3: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline] #3: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa6/0x2550 arch/x86/kernel/unwind_orc.c:495 8 locks held by kworker/1:0/32: #0: ffff88813fe4a538 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc90000a6fc40 ((work_completion)(&(&tbl->gc_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffffffff8de61600 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #3: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #4: ffffffff8f4ade38 (&tbl->lock){+...}-{3:3}, at: spin_lock_bh include/linux/spinlock_rt.h:90 [inline] #4: ffffffff8f4ade38 (&tbl->lock){+...}-{3:3}, at: neigh_periodic_work+0xc64/0xe90 net/core/neighbour.c:1040 #5: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #5: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #5: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #5: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #6: ffff88803c814740 (&dir->lock#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #6: ffff88803c814740 (&dir->lock#2){+.+.}-{3:3}, at: ref_tracker_free+0x13d/0x820 lib/ref_tracker.c:310 #7: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #7: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #7: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #7: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 1 lock held by khungtaskd/38: #0: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 3 locks held by kworker/1:1/43: #0: ffff88813fe4b938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc90000b57c40 (rx_mode_work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: netdev_rx_mode_work+0x1c/0x460 net/core/dev_addr_lists.c:1312 3 locks held by kworker/1:2/869: #0: ffff88813fe4b938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc90005a37c40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 4 locks held by kworker/u8:9/1032: #0: ffff88801b68e138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc90005f4fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffffffff8f370540 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 #3: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940 net/core/net_namespace.c:248 3 locks held by kworker/u8:15/3398: #0: ffff88813fe84138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc9000f927c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 2 locks held by dhcpcd/5277: #0: ffff88806534e928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2405 #1: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6878 2 locks held by getty/5370: #0: ffff8880364c60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 9 locks held by syz-executor/5617: #0: ffffffff8e09d1f0 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline] #0: ffffffff8e09d1f0 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x10f/0x480 kernel/fork.c:1594 #1: ffff8880367e11b0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline] #1: ffff8880367e11b0 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x184/0x1d70 mm/mmap.c:1739 #2: ffff88803ae21f30 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:544 [inline] #2: ffff88803ae21f30 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x272/0x1d70 mm/mmap.c:1746 #3: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290 #4: ffff88803953f058 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #4: ffff88803953f058 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404 #5: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #5: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #5: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #5: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #6: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #6: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #6: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290 #7: ffff88805b2c6dd8 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pte_range mm/memory.c:1272 [inline] #7: ffff88805b2c6dd8 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pmd_range+0x5ae/0x5550 mm/memory.c:1408 #8: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #8: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #8: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #8: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock_nested+0x1de/0x3f0 kernel/locking/spinlock_rt.c:65 1 lock held by syz-executor/17245: #0: ffff888036aae480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494 3 locks held by kworker/1:3/17810: #0: ffff88813fe4a538 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc90005e8fc40 ((gc_work).work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffffffff8dfcabc0 (rcu_read_lock){....}-{1:3}, at: wg_ratelimiter_gc_entries+0x5d/0x480 drivers/net/wireguard/ratelimiter.c:63 3 locks held by syz.7.5162/19143: #0: ffff88803f953f28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1260 #1: ffff88803534a480 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #1: ffff88803534a480 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #2: ffff88803a8cf878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 1 lock held by syz-executor/22403: #0: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4122 2 locks held by syz-executor/22468: #0: ffffffff8f8c0938 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8f8c0938 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8f8c0938 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4122 2 locks held by syz.2.6481/22717: #0: ffffffff8f3f0600 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8f37fa78 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x8d0 net/wireless/nl80211.c:19267 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:119 nmi_trigger_cpumask_backtrace+0x17a/0x380 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+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 17810 Comm: kworker/1:3 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events_power_efficient wg_ratelimiter_gc_entries RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5604 [inline] RIP: 0010:lock_is_held_type+0xb7/0x150 kernel/locking/lockdep.c:5942 Code: 49 ff c7 49 63 85 f8 0b 00 00 48 83 c3 28 49 39 c7 7c d8 eb 11 48 c7 c7 10 84 e9 8d 4c 89 fe e8 ef ce bd f9 eb cb 31 db eb 1c <83> fd ff 74 12 31 c0 f6 43 22 03 0f 95 c0 31 db 39 c5 0f 94 c3 eb RSP: 0018:ffffc90005e8f788 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffff88804d622b78 RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8eabf6d8 RDI: ffff88804d622b78 RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000bd1f30 R12: 0000000000000046 R13: ffff88804d621f00 R14: ffffffff8eabf6d8 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff888125fec000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb8b3892b00 CR3: 0000000051550000 CR4: 00000000003526f0 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] rtlock_slowlock_locked+0xde/0x3c80 kernel/locking/rtmutex.c:1859 rtlock_slowlock kernel/locking/rtmutex.c:1918 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x165/0x400 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:45 [inline] wg_ratelimiter_gc_entries+0x5d/0x480 drivers/net/wireguard/ratelimiter.c:63 process_one_work+0x98b/0x1630 kernel/workqueue.c:3318 process_scheduled_works kernel/workqueue.c:3401 [inline] worker_thread+0xb49/0x1140 kernel/workqueue.c:3482 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