INFO: task syz.1.2103:10266 blocked for more than 152 seconds. Not tainted 6.12.0-rc7-syzkaller-00125-gcfaaa7d010d1 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.2103 state:D stack:28288 pid:10266 tgid:10261 ppid:5828 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0xe55/0x5740 kernel/sched/core.c:6693 __schedule_loop kernel/sched/core.c:6770 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6785 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6842 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 ptmx_open drivers/tty/pty.c:823 [inline] ptmx_open+0xf6/0x350 drivers/tty/pty.c:790 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x6ca/0x1530 fs/open.c:958 vfs_open+0x82/0x3f0 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x1e6a/0x2d60 fs/namei.c:3933 do_filp_open+0x1dc/0x430 fs/namei.c:3960 do_sys_openat2+0x17a/0x1e0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1441 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: 0033:0x7f397097e719 RSP: 002b:00007f3971703038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f3970b35f80 RCX: 00007f397097e719 RDX: 0000000000000400 RSI: 00000000200000c0 RDI: ffffffffffffff9c RBP: 00007f39709f175e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f3970b35f80 R15: 00007fffc4202848 Showing all locks held in the system: 2 locks held by kworker/0:1/9: 3 locks held by kworker/u8:1/12: 1 lock held by khungtaskd/30: #0: ffffffff8e1b8340 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1b8340 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1b8340 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 3 locks held by kworker/u8:2/33: 3 locks held by kworker/u8:3/52: 3 locks held by kworker/u8:4/61: 3 locks held by kworker/u8:5/140: 3 locks held by kworker/u8:6/2986: 3 locks held by kworker/R-bat_e/3385: 3 locks held by kworker/u8:7/3943: 4 locks held by kworker/u9:1/5140: 3 locks held by syslogd/5181: 2 locks held by dhcpcd/5492: 2 locks held by getty/5581: #0: ffff8880361920a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5811: 3 locks held by syz-executor/5821: 1 lock held by syz-executor/5822: 4 locks held by syz-executor/5826: 2 locks held by syz-executor/5835: 1 lock held by syz.1.2103/10266: #0: ffffffff8ee6a708 (tty_mutex){+.+.}-{3:3}, at: ptmx_open drivers/tty/pty.c:823 [inline] #0: ffffffff8ee6a708 (tty_mutex){+.+.}-{3:3}, at: ptmx_open+0xf6/0x350 drivers/tty/pty.c:790 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc7-syzkaller-00125-gcfaaa7d010d1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 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:223 [inline] watchdog+0xf0c/0x1240 kernel/hung_task.c:379 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3385 Comm: kworker/R-bat_e Not tainted 6.12.0-rc7-syzkaller-00125-gcfaaa7d010d1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Workqueue: bat_events batadv_tt_purge RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 7e 60 e8 a3 ff ff ff 31 c0 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 65 48 8b 15 94 60 76 7e 65 8b 05 95 60 76 7e a9 00 01 RSP: 0018:ffffc90000a18360 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffff8880288c4cc0 RCX: ffffffff89edd307 RDX: ffff8880329e8000 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 0000000000007530 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000007530 R11: 0000000000000000 R12: 1ffff92000143071 R13: ffff8880601ab000 R14: 0000000000000000 R15: 00000000000005dc FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f03d9a0bcbf CR3: 000000000df7c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: br_fdb_update+0x15f/0x7c0 net/bridge/br_fdb.c:899 br_handle_frame_finish+0xd77/0x1c80 net/bridge/br_input.c:141 br_nf_hook_thresh+0x303/0x410 net/bridge/br_netfilter_hooks.c:1195 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:533 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+0xa3d/0x4330 net/core/dev.c:5564 __netif_receive_skb_one_core+0xb1/0x1e0 net/core/dev.c:5668 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5783 process_backlog+0x443/0x15f0 net/core/dev.c:6115 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6779 napi_poll net/core/dev.c:6848 [inline] net_rx_action+0xa92/0x1010 net/core/dev.c:6970 handle_softirqs+0x213/0x8f0 kernel/softirq.c:554 do_softirq kernel/softirq.c:455 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:442 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:382 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x21c/0x3c0 net/batman-adv/translation-table.c:1356 batadv_tt_purge+0x86/0xb90 net/batman-adv/translation-table.c:3560 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] rescuer_thread+0x628/0xe20 kernel/workqueue.c:3487 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