INFO: task syslogd:5178 blocked for more than 143 seconds. Not tainted 6.14.0-rc6-syzkaller-00003-g4d872d51bc9d #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syslogd state:D stack:24240 pid:5178 tgid:5178 ppid:1 task_flags:0x400000 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75 ___down_common+0x2d7/0x460 kernel/locking/semaphore.c:225 __down_common kernel/locking/semaphore.c:246 [inline] __down+0x20/0x30 kernel/locking/semaphore.c:254 down+0x74/0xa0 kernel/locking/semaphore.c:63 console_lock+0x5b/0xa0 kernel/printk/printk.c:2833 console_device+0x19/0x180 kernel/printk/printk.c:3482 tty_lookup_driver+0x2fb/0x510 drivers/tty/tty_io.c:1930 tty_open_by_driver drivers/tty/tty_io.c:2047 [inline] tty_open+0x54e/0xf80 drivers/tty/tty_io.c:2129 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x735/0x1c40 fs/open.c:956 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x1e88/0x2d80 fs/namei.c:3989 do_filp_open+0x20c/0x470 fs/namei.c:4016 do_sys_openat2+0x17a/0x1e0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f546d1299a4 RSP: 002b:00007ffd7bfa9680 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f546d1299a4 RDX: 0000000000000901 RSI: 00007f546d2c83b3 RDI: 00000000ffffff9c RBP: 00007f546d2c83b3 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000901 R13: 0000000000000901 R14: 0000000000000901 R15: 000055d5dc84e410 Showing all locks held in the system: 2 locks held by kworker/0:1/10: 3 locks held by kworker/u8:0/12: 1 lock held by khungtaskd/31: #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746 3 locks held by kworker/u8:2/36: 3 locks held by kworker/u8:4/67: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc90001577d18 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8fef7f68 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:285 3 locks held by kworker/u8:8/3920: 1 lock held by syslogd/5178: #0: ffffffff8ee88828 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] #0: ffffffff8ee88828 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129 1 lock held by udevd/5196: 2 locks held by dhcpcd/5489: 2 locks held by getty/5572: #0: ffff88803267b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000330b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5818: #0: ffff888031634d88 (&xt[i].mutex){+.+.}-{4:4}, at: xt_find_target+0xab/0x290 net/netfilter/x_tables.c:254 1 lock held by syz-executor/5819: 2 locks held by syz-executor/5831: 4 locks held by kworker/1:6/5868: 2 locks held by syz.4.6595/19927: 6 locks held by syz.2.6624/19992: 5 locks held by kworker/u8:5/19999: 2 locks held by kworker/u8:6/20000: 3 locks held by kworker/0:0/20001: 3 locks held by kworker/u8:10/20006: 3 locks held by syz-executor/20010: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller-00003-g4d872d51bc9d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0xf62/0x12b0 kernel/hung_task.c:399 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 19999 Comm: kworker/u8:5 Not tainted 6.14.0-rc6-syzkaller-00003-g4d872d51bc9d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: bat_events batadv_tt_purge RIP: 0010:br_handle_frame+0x338/0x14a0 net/bridge/br_input.c:353 Code: 85 db 0f 85 15 08 00 00 e8 85 cd 90 f7 48 8b 04 24 48 8d 78 28 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <0f> 85 bd 0f 00 00 48 8b 04 24 31 ff 48 8b 40 28 48 89 c3 48 89 44 RSP: 0018:ffffc90000007870 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff8a292b80 RDX: 1ffff11004ab8e05 RSI: ffffffff8a29235b RDI: ffff8880255c7028 RBP: ffff88816d697c80 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: ffff888021f28002 R13: 00000000aaaaaaaa R14: ffffc90000007a68 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8a11377d38 CR3: 000000007d68a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __netif_receive_skb_core.constprop.0+0xa20/0x4330 net/core/dev.c:5787 __netif_receive_skb_one_core+0xb1/0x1e0 net/core/dev.c:5891 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6006 process_backlog+0x443/0x15f0 net/core/dev.c:6354 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7188 napi_poll net/core/dev.c:7257 [inline] net_rx_action+0xa94/0x1010 net/core/dev.c:7379 handle_softirqs+0x213/0x8f0 kernel/softirq.c:561 do_softirq kernel/softirq.c:462 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:449 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:389 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x21c/0x3c0 net/batman-adv/translation-table.c:1315 batadv_tt_purge+0x86/0xb90 net/batman-adv/translation-table.c:3509 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244