INFO: task syslogd:5165 blocked for more than 154 seconds. Not tainted 6.15.0-rc4-syzkaller-00042-gb6ea1680d0ac #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syslogd state:D stack:24664 pid:5165 tgid:5165 ppid:1 task_flags:0x400000 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 ___down_common+0x2d8/0x460 kernel/locking/semaphore.c:229 __down_common kernel/locking/semaphore.c:250 [inline] __down+0x20/0x30 kernel/locking/semaphore.c:258 down+0x74/0xa0 kernel/locking/semaphore.c:64 console_lock+0x5b/0xa0 kernel/printk/printk.c:2849 console_device+0x19/0x180 kernel/printk/printk.c:3508 tty_lookup_driver+0x2fb/0x510 drivers/tty/tty_io.c:1930 tty_open_by_driver drivers/tty/tty_io.c:2047 [inline] tty_open+0x54f/0xf90 drivers/tty/tty_io.c:2129 chrdev_open+0x231/0x6a0 fs/char_dev.c:414 do_dentry_open+0x741/0x1c10 fs/open.c:956 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3880 [inline] path_openat+0x1e5e/0x2d40 fs/namei.c:4039 do_filp_open+0x20b/0x470 fs/namei.c:4066 do_sys_openat2+0x11b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4193cbd9a4 RSP: 002b:00007ffc7135e280 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f4193cbd9a4 RDX: 0000000000000901 RSI: 00007f4193e5c3b3 RDI: 00000000ffffff9c RBP: 00007f4193e5c3b3 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000901 R13: 0000000000000901 R14: 0000000000000901 R15: 0000558e49940410 Showing all locks held in the system: 2 locks held by kthreadd/2: 1 lock held by pool_workqueue_/3: #0: ffffffff8e3caaf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 1 lock held by kworker/R-kvfre/6: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2678 3 locks held by kworker/0:0/9: 2 locks held by kworker/0:1/10: 4 locks held by kworker/u8:0/12: 4 locks held by kworker/u8:1/13: 1 lock held by kworker/R-mm_pe/14: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2736 [inline] #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 3 locks held by kworker/1:0/24: #0: ffff88802863e548 ((wq_completion)wg-kex-wg0#8){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc900001e7d18 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __asm__ ("" : "=r"(__ptr) : "0"((__typeof__(*((worker))) *)(( unsigned long)((worker))))); (typeof((__typeof__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88805bdcd278 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_begin_session+0x30/0xe80 drivers/net/wireguard/noise.c:822 1 lock held by khungtaskd/31: #0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764 1 lock held by kworker/R-write/33: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2678 4 locks held by kworker/u8:2/36: #0: ffff88805d367948 ((wq_completion)wg-kex-wg2){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90000ad7d18 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88807dc95308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0xec/0x650 drivers/net/wireguard/noise.c:529 #3: ffff888078f7e648 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x100/0x650 drivers/net/wireguard/noise.c:530 2 locks held by kworker/1:1/52: 4 locks held by kworker/u8:3/53: 7 locks held by kworker/u8:4/70: 4 locks held by kworker/0:2/92: 3 locks held by kworker/u8:5/1311: 1 lock held by kworker/R-dm_bu/2805: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2736 [inline] #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 3 locks held by kworker/1:2/3071: #0: ffff88805c967148 ((wq_completion)wg-kex-wg2#8){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000c577d18 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __asm__ ("" : "=r"(__ptr) : "0"((__typeof__(*((worker))) *)(( unsigned long)((worker))))); (typeof((__typeof__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff8880697d0d20 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_begin_session+0x30/0xe80 drivers/net/wireguard/noise.c:822 1 lock held by kworker/R-bat_e/3391: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2736 [inline] #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 4 locks held by kworker/u8:6/3509: 4 locks held by kworker/u8:7/4230: #0: ffff88814dcfe948 ((wq_completion)wg-kex-wg2#7){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000e2e7d18 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff8880294b1308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0xec/0x650 drivers/net/wireguard/noise.c:529 #3: ffff8880697d0d20 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x100/0x650 drivers/net/wireguard/noise.c:530 1 lock held by kworker/R-ext4-/5146: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2678 1 lock held by syslogd/5165: #0: ffffffff8f0a5a28 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] #0: ffffffff8f0a5a28 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2129 2 locks held by udevd/5183: 2 locks held by dhcpcd/5476: 2 locks held by getty/5559: #0: ffff888031e870a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by kworker/0:3/5835: #0: ffff88807dd42548 ((wq_completion)wg-kex-wg2#4){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003177d18 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __asm__ ("" : "=r"(__ptr) : "0"((__typeof__(*((worker))) *)(( unsigned long)((worker))))); (typeof((__typeof__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff8880313aa0f0 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_begin_session+0x30/0xe80 drivers/net/wireguard/noise.c:822 4 locks held by kworker/1:3/5854: #0: ffff888079ab5d48 ((wq_completion)wg-kex-wg0#10){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003167d18 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __asm__ ("" : "=r"(__ptr) : "0"((__typeof__(*((worker))) *)(( unsigned long)((worker))))); (typeof((__typeof__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff888027a99308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x1c2/0x880 drivers/net/wireguard/noise.c:598 #3: ffff8880697d1708 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x5ac/0x880 drivers/net/wireguard/noise.c:632 3 locks held by kworker/1:4/5901: 2 locks held by syz-executor/5915: #0: ffffffff901243a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff901243a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3390 #1: ffffffff8e3caaf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x280/0x3c0 kernel/rcu/tree_exp.h:304 2 locks held by syz-executor/5916: 1 lock held by syz-executor/5924: 2 locks held by syz-executor/5929: 1 lock held by kworker/R-wg-cr/5941: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2736 [inline] #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 1 lock held by kworker/R-wg-cr/5944: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2678 1 lock held by kworker/R-wg-cr/5951: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2678 1 lock held by kworker/R-wg-cr/5953: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2678 1 lock held by kworker/R-wg-cr/5959: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2678 1 lock held by kworker/R-wg-cr/5961: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2678 1 lock held by kworker/R-wg-cr/5962: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2678 1 lock held by kworker/R-wg-cr/5963: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2678 1 lock held by kworker/R-wg-cr/5976: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2678 1 lock held by kworker/R-wg-cr/5977: 1 lock held by kworker/R-wg-cr/5978: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2678 4 locks held by kworker/1:6/6020: 2 locks held by kworker/0:4/6044: 3 locks held by kworker/1:7/6082: 4 locks held by kworker/0:5/6164: #0: ffff88805cd73948 ((wq_completion)wg-kex-wg2#2){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003077d18 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __asm__ ("" : "=r"(__ptr) : "0"((__typeof__(*((worker))) *)(( unsigned long)((worker))))); (typeof((__typeof__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88807dc95308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x1c2/0x880 drivers/net/wireguard/noise.c:598 #3: ffff888078f7e648 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x5ac/0x880 drivers/net/wireguard/noise.c:632 4 locks held by kworker/1:8/6165: 3 locks held by kworker/0:6/7380: 6 locks held by syz.3.4950/16176: 3 locks held by kworker/u8:8/16212: 4 locks held by kworker/u8:9/16213: 1 lock held by kworker/u8:10/16214: #0: ffffffff8e2770c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2678 2 locks held by syz-executor/16217: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00042-gb6ea1680d0ac #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:437 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 70 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00042-gb6ea1680d0ac #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker RIP: 0010:match_held_lock+0x0/0xc0 kernel/locking/lockdep.c:5303 Code: 20 de a1 8d e8 41 4a 0e f6 90 0f 0b 90 90 e9 58 ff ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <53> 48 89 fb 48 39 77 10 74 55 66 83 7f 22 1f 76 65 48 8b 46 08 48 RSP: 0018:ffffc90000007368 EFLAGS: 00000093 RAX: 000000000000000a RBX: ffff88801d360b40 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff901243a8 RDI: ffff88801d360b40 RBP: ffffffff901243a8 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88801d360000 R13: ffff88801d360af0 R14: 00000000ffffffff R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8881249e2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f015a17d2d8 CR3: 000000000e180000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_is_held kernel/locking/lockdep.c:5599 [inline] lock_is_held_type+0xb0/0x150 kernel/locking/lockdep.c:5938 lock_is_held include/linux/lockdep.h:249 [inline] lockdep_rtnl_is_held+0x1b/0x40 net/core/rtnetlink.c:182 __in6_dev_get include/net/addrconf.h:347 [inline] ip6_ignore_linkdown include/net/addrconf.h:443 [inline] find_match+0x34b/0x15d0 net/ipv6/route.c:781 __find_rr_leaf+0x140/0xe00 net/ipv6/route.c:869 find_rr_leaf net/ipv6/route.c:890 [inline] rt6_select net/ipv6/route.c:934 [inline] fib6_table_lookup+0x57c/0xa30 net/ipv6/route.c:2230 ip6_pol_route+0x1cc/0x1230 net/ipv6/route.c:2266 pol_lookup_func include/net/ip6_fib.h:616 [inline] fib6_rule_lookup+0x536/0x720 net/ipv6/fib6_rules.c:120 ip6_route_input_lookup net/ipv6/route.c:2335 [inline] ip6_route_input+0x662/0xc00 net/ipv6/route.c:2631 ip6_rcv_finish_core.constprop.0+0x1a0/0x5d0 net/ipv6/ip6_input.c:66 ip6_rcv_finish net/ipv6/ip6_input.c:77 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ipv6_rcv+0x1e8/0x680 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:5887 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6000 process_backlog+0x442/0x15e0 net/core/dev.c:6352 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7324 napi_poll net/core/dev.c:7388 [inline] net_rx_action+0xa97/0x1010 net/core/dev.c:7510 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 do_softirq kernel/softirq.c:480 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:467 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:407 local_bh_enable include/linux/bottom_half.h:33 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:77 [inline] kernel_fpu_end+0x5e/0x70 arch/x86/kernel/fpu/core.c:460 blake2s_compress+0x7f/0xe0 arch/x86/crypto/blake2s-glue.c:49 blake2s_update+0xef/0x360 lib/crypto/blake2s.c:32 blake2s.constprop.0+0xb1/0x100 include/crypto/blake2s.h:100 compute_mac1 drivers/net/wireguard/cookie.c:80 [inline] wg_cookie_add_mac_to_packet+0x52/0x1c0 drivers/net/wireguard/cookie.c:163 wg_packet_send_handshake_initiation+0x1c4/0x360 drivers/net/wireguard/send.c:35 wg_packet_handshake_send_worker+0x1c/0x30 drivers/net/wireguard/send.c:51 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245