syzbot

INFO: task syslogd:5168 blocked for more than 149 seconds.
      Not tainted 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syslogd         state:D stack:24512 pid:5168  tgid:5168  ppid:1      task_flags:0x400000 flags:0x00000002
Call Trace:
 <TASK>
 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: 0033:0x7f7f79fdf9a4
RSP: 002b:00007ffc67cd6e70 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f7f79fdf9a4
RDX: 0000000000000901 RSI: 00007f7f7a17e3b3 RDI: 00000000ffffff9c
RBP: 00007f7f7a17e3b3 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000901
R13: 0000000000000901 R14: 0000000000000901 R15: 000055d8554c3410
 </TASK>

Showing all locks held in the system:
1 lock held by kthreadd/2:
2 locks held by kworker/0:0/9:
2 locks held by kworker/0:1/10:
4 locks held by kworker/u8:0/12:
3 locks held by kworker/u8:1/13:
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
3 locks held by kworker/u8:2/36:
3 locks held by kworker/u8:3/52:
3 locks held by kworker/0:2/973:
4 locks held by kworker/u8:5/1088:
4 locks held by kworker/u8:6/1336:
3 locks held by kworker/u8:8/3499:
5 locks held by kworker/u8:9/3563:
1 lock held by syslogd/5168:
 #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 dhcpcd/5479:
2 locks held by getty/5567:
 #0: ffff88814e7280a0 (&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
1 lock held by syz-executor/5798:
3 locks held by syz-executor/5808:
1 lock held by syz-executor/5810:
1 lock held by syz-executor/5811:
3 locks held by kworker/1:3/5814:
2 locks held by kworker/1:4/5861:
4 locks held by kworker/0:3/5862:
4 locks held by kworker/1:6/5864:
 #0: ffff888034207548 ((wq_completion)wg-kex-wg0#2){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc90002f07d18 ((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: ffff88805dead308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_response+0xc5/0x640 drivers/net/wireguard/noise.c:678
 #3: ffff88807c278338 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_response+0xd8/0x640 drivers/net/wireguard/noise.c:679
2 locks held by kworker/1:7/5865:
3 locks held by kworker/0:4/5866:
3 locks held by kworker/0:5/5897:
4 locks held by kworker/0:6/5902:
6 locks held by syz.4.6382/19277:
4 locks held by kworker/u8:4/19300:
2 locks held by kworker/u8:7/19301:
4 locks held by kworker/u8:10/19304:
2 locks held by kworker/1:5/19305:
2 locks held by kworker/u8:11/19306:
3 locks held by kworker/1:8/19307:
3 locks held by kworker/0:7/19308:

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
 <TASK>
 __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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 3563 Comm: kworker/u8:9 Not tainted 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:__lock_acquire+0xf3/0x1ba0 kernel/locking/lockdep.c:5143
Code: 00 48 2d 60 8f aa 95 48 89 c5 48 b8 29 5c 8f c2 f5 28 5c 8f 48 c1 fd 03 48 89 e9 49 8d ae f0 0a 00 00 48 0f af c8 8b 44 24 08 <48> 8d 1c 80 48 89 4c 24 10 48 c1 e3 03 85 c0 74 25 f6 84 24 c8 00
RSP: 0018:ffffc900000074b0 EFLAGS: 00000803
RAX: 0000000000000005 RBX: 0000000000000000 RCX: 0000000000000007
RDX: 0000000000000000 RSI: 0000000000000005 RDI: ffffffff8e3bf5c0
RBP: ffff888032b4d370 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: ffffffff8e3bf5c0 R12: 0000000000000000
R13: 0000000000000002 R14: ffff888032b4c880 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881249e2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fac70980ef8 CR3: 000000000e180000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire kernel/locking/lockdep.c:5866 [inline]
 lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2398 [inline]
 slab_free mm/slub.c:4656 [inline]
 kmem_cache_free+0x2d4/0x4d0 mm/slub.c:4758
 kfree_skbmem+0x1a4/0x1f0 net/core/skbuff.c:1120
 __kfree_skb net/core/skbuff.c:1177 [inline]
 sk_skb_reason_drop+0x136/0x1a0 net/core/skbuff.c:1214
 kfree_skb_reason include/linux/skbuff.h:1279 [inline]
 kfree_skb include/linux/skbuff.h:1288 [inline]
 ip6_mc_input+0x780/0xfd0 net/ipv6/ip6_input.c:591
 dst_input include/net/dst.h:469 [inline]
 dst_input include/net/dst.h:467 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline]
 NF_HOOK include/linux/netfilter.h:314 [inline]
 NF_HOOK include/linux/netfilter.h:308 [inline]
 ipv6_rcv+0x45a/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
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:407
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
 nsim_dev_trap_report_work+0x8b5/0xcf0 drivers/net/netdevsim/dev.c:851
 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
 </TASK>