INFO: task syz.6.2705:17304 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.2705 state:D stack:24592 pid:17304 ppid: 15402 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 perf_pending_task_sync+0x13c/0x1c0 kernel/events/core.c:5127 _free_event+0x34/0xe60 kernel/events/core.c:5133 put_event kernel/events/core.c:5258 [inline] perf_event_release_kernel+0x83e/0x8d0 kernel/events/core.c:5383 perf_release+0x37/0x40 kernel/events/core.c:5393 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc2c4b06f79 RSP: 002b:00007fc2c2d61028 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 00007fc2c4d80fa0 RCX: 00007fc2c4b06f79 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fc2c4b9d7e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc2c4d81038 R14: 00007fc2c4d80fa0 R15: 00007ffd8fa041e8 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3946: #0: ffff88802beb9098 (&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+0x5df/0x1a70 drivers/tty/n_tty.c:2158 2 locks held by kworker/u4:8/4753: 3 locks held by kworker/0:16/8964: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90002d8fd00 (fqdir_free_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8c323430 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4c0 kernel/rcu/tree.c:4043 2 locks held by kworker/0:40/9000: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000305fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 6 locks held by kworker/u4:1/15372: #0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900046e7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8d430850 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589 #3: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: caif_exit_net+0x66/0x480 net/caif/caif_dev.c:527 #4: ffff888052fe3b80 (&caifn->caifdevs.lock){+.+.}-{3:3}, at: caif_exit_net+0x79/0x480 net/caif/caif_dev.c:528 #5: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #5: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 1 lock held by syz.0.3726/22481: #0: ffffffff8c36c168 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 1 lock held by syz.9.3732/22508: #0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5681 4 locks held by syz.8.3734/22519: #0: ffffffff96329918 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:313 #1: ffffffff8c36c168 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x4c/0x2d0 kernel/trace/trace_event_perf.c:221 #2: ffffffff8c35e808 (tracepoints_mutex){+.+.}-{3:3}, at: tracepoint_probe_register_prio kernel/tracepoint.c:507 [inline] #2: ffffffff8c35e808 (tracepoints_mutex){+.+.}-{3:3}, at: tracepoint_probe_register+0x3c/0x90 kernel/tracepoint.c:531 #3: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #3: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 1 lock held by syz.8.3734/22522: #0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x700 net/netlink/af_netlink.c:2352 1 lock held by syz.1.3733/22521: #0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440 2 locks held by syz.1.3733/22527: #0: ffffffff8cccf328 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0xdc/0x1a80 drivers/net/ppp/ppp_generic.c:738 #1: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: ppp_create_interface drivers/net/ppp/ppp_generic.c:3359 [inline] #1: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1069 [inline] #1: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x689/0x1a80 drivers/net/ppp/ppp_generic.c:742 1 lock held by syz.1.3733/22529: #0: ffffffff8cccf328 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0xdc/0x1a80 drivers/net/ppp/ppp_generic.c:738 1 lock held by dhcpcd-run-hook/22543: ============================================= 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 02/12/2026 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+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 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: 4298 Comm: kworker/u4:6 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker RIP: 0010:preempt_count_add+0x0/0x190 kernel/sched/core.c:5499 Code: 24 80 e1 07 80 c1 03 38 c1 7c 97 48 8b 3c 24 e8 96 cd 6b 00 eb 8c e9 f5 fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <41> 57 41 56 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0 80 8f 2d 96 RSP: 0018:ffffc9000440f298 EFLAGS: 00000293 RAX: ffffffff812c095b RBX: 0000000000000001 RCX: ffff888020ab3b80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffffc9000440f360 R08: ffffc9000440f48f R09: ffffc9000440f451 R10: dffffc0000000000 R11: fffff52000881e92 R12: 1ffff92000881e58 R13: dffffc0000000000 R14: 0000000000000001 R15: ffffc9000440f450 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110e22fff6 CR3: 000000002ac47000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: kernel_fpu_begin_mask+0x75/0x440 arch/x86/kernel/fpu/core.c:141 kernel_fpu_begin arch/x86/include/asm/fpu/api.h:40 [inline] blake2s_compress+0x3f/0xc0 arch/x86/crypto/blake2s-glue.c:44 blake2s_final+0xae/0x190 lib/crypto/blake2s.c:54 hmac+0x20a/0x3b0 drivers/net/wireguard/noise.c:325 kdf drivers/net/wireguard/noise.c:367 [inline] message_ephemeral+0x252/0x310 drivers/net/wireguard/noise.c:493 wg_noise_handshake_create_initiation+0x3da/0x910 drivers/net/wireguard/noise.c:545 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0x18b/0x340 drivers/net/wireguard/send.c:51 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287