INFO: task syslogd:5172 blocked for more than 144 seconds. Not tainted 6.13.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syslogd state:D stack:24208 pid:5172 tgid:5172 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 __mutex_lock_common kernel/locking/mutex.c:665 [inline] __mutex_lock+0x62b/0xa60 kernel/locking/mutex.c:735 tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0xf59/0x1ea0 fs/open.c:945 vfs_open+0x82/0x3f0 fs/open.c:1075 do_open fs/namei.c:3828 [inline] path_openat+0x1e6a/0x2d60 fs/namei.c:3987 do_filp_open+0x20c/0x470 fs/namei.c:4014 do_sys_openat2+0x17a/0x1e0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_openat fs/open.c:1433 [inline] __se_sys_openat fs/open.c:1428 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1428 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: 0033:0x7fc45faf99a4 RSP: 002b:00007ffe6c7b7300 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fc45faf99a4 RDX: 0000000000000901 RSI: 00007fc45fc983b3 RDI: 00000000ffffff9c RBP: 00007fc45fc983b3 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000901 R13: 0000000000000901 R14: 0000000000000901 R15: 0000561d306ac410 INFO: task syz.4.5622:18925 blocked for more than 144 seconds. Not tainted 6.13.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.5622 state:D stack:28416 pid:18925 tgid:18921 ppid:5826 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 __mutex_lock_common kernel/locking/mutex.c:665 [inline] __mutex_lock+0x62b/0xa60 kernel/locking/mutex.c:735 tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0xf59/0x1ea0 fs/open.c:945 vfs_open+0x82/0x3f0 fs/open.c:1075 do_open fs/namei.c:3828 [inline] path_openat+0x1e6a/0x2d60 fs/namei.c:3987 do_filp_open+0x20c/0x470 fs/namei.c:4014 do_sys_openat2+0x17a/0x1e0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_openat fs/open.c:1433 [inline] __se_sys_openat fs/open.c:1428 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1428 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: 0033:0x7fe4d9184690 RSP: 002b:00007fe4d9fe8b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fe4d9184690 RDX: 0000000000000002 RSI: 00007fe4d9fe8c10 RDI: 00000000ffffff9c RBP: 00007fe4d9fe8c10 R08: 0000000000000000 R09: 00007fe4d9fe8987 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe4d9376080 R15: 00007ffe00d7d868 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e1c7238 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329 3 locks held by kworker/u8:0/11: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc90000107d80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 #2: ffffffff8fee0048 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:285 1 lock held by khungtaskd/30: #0: ffffffff8e1bb900 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1bb900 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1bb900 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6744 4 locks held by kworker/u8:5/1100: 3 locks held by kworker/u8:6/1157: 3 locks held by kworker/u8:7/4556: 1 lock held by syslogd/5172: #0: ffffffff8ee71e68 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] #0: ffffffff8ee71e68 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129 1 lock held by udevd/5190: 2 locks held by dhcpcd/5483: 6 locks held by dhcpcd/5484: 2 locks held by getty/5567: #0: ffff888033aa00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 5 locks held by syz-executor/5812: 2 locks held by syz-executor/5817: #0: ffffffff8fee0048 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fee0048 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3517 #1: ffffffff8e1c7238 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329 3 locks held by syz-executor/5823: 3 locks held by kworker/0:3/5860: 2 locks held by kworker/0:4/5861: 2 locks held by kworker/0:5/5862: 3 locks held by kworker/1:5/5863: 2 locks held by kworker/0:8/5893: 2 locks held by kworker/u8:9/13170: 3 locks held by kworker/u8:10/13175: 4 locks held by syz.4.5622/18922: 1 lock held by syz.4.5622/18925: #0: ffffffff8ee71e68 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] #0: ffffffff8ee71e68 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129 3 locks held by kworker/u8:11/18933: 3 locks held by kworker/0:7/18935: #0: ffff88801b078948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc90010187d80 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 #2: ffffffff8fee0048 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by syz-executor/18936: 1 lock held by syz-executor/18937: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 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:234 [inline] watchdog+0xf14/0x1240 kernel/hung_task.c:397 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 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: 13170 Comm: kworker/u8:9 Not tainted 6.13.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: bat_events batadv_tt_purge RIP: 0010:br_multicast_ipv6_rcv net/bridge/br_multicast.c:3883 [inline] RIP: 0010:br_multicast_rcv+0x4ad/0x6a10 net/bridge/br_multicast.c:3972 Code: 85 2d 25 00 00 49 8b 07 48 89 da 48 c1 ea 03 48 89 85 88 fe ff ff 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 0f 85 bb 59 00 00 <48> c7 85 70 fe ff ff 00 00 00 00 48 8b 03 48 8b 9d 88 fe ff ff 48 RSP: 0018:ffffc900000071f0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffc900000074c0 RCX: ffffffff8a036841 RDX: 1ffff92000000e98 RSI: ffffffff8a03685d RDI: 0000000000000003 RBP: ffffc90000007400 R08: 0000000000000003 R09: 000000000000dd86 R10: 000000000000dd86 R11: 0000000000000003 R12: ffff8880799d4834 R13: ffff8880282bcd80 R14: 000000000000dd86 R15: ffffc900000074a0 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1c6185d27a CR3: 000000000df7e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: br_handle_frame_finish+0x107f/0x1c80 net/bridge/br_input.c:153 br_nf_hook_thresh+0x303/0x410 net/bridge/br_netfilter_hooks.c:1198 br_nf_pre_routing_finish_ipv6+0x76a/0xfb0 net/bridge/br_netfilter_ipv6.c:154 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x3ce/0x8c0 net/bridge/br_netfilter_ipv6.c:184 br_nf_pre_routing+0x860/0x15b0 net/bridge/br_netfilter_hooks.c:536 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x9eb/0x1490 net/bridge/br_input.c:424 __netif_receive_skb_core.constprop.0+0xa76/0x4470 net/core/dev.c:5598 __netif_receive_skb_one_core+0xb1/0x1e0 net/core/dev.c:5702 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5817 process_backlog+0x443/0x15f0 net/core/dev.c:6149 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6902 napi_poll net/core/dev.c:6971 [inline] net_rx_action+0xa94/0x1010 net/core/dev.c:7093 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_global_purge net/batman-adv/translation-table.c:2272 [inline] batadv_tt_purge+0x251/0xb90 net/batman-adv/translation-table.c:3532 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244