INFO: task syz.0.2458:12445 blocked for more than 144 seconds. Not tainted 6.13.0-syzkaller-08265-g9c5968db9e62 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2458 state:D stack:28512 pid:12445 tgid:12441 ppid:5821 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6856 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 do_con_write+0x154/0x7bb0 drivers/tty/vt/vt.c:3056 con_write+0x23/0xb0 drivers/tty/vt/vt.c:3434 do_output_char+0x5d6/0x840 drivers/tty/n_tty.c:428 process_output drivers/tty/n_tty.c:494 [inline] n_tty_write+0x4c3/0x1140 drivers/tty/n_tty.c:2400 iterate_tty_write drivers/tty/tty_io.c:1015 [inline] file_tty_write.constprop.0+0x506/0x9a0 drivers/tty/tty_io.c:1090 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x5ae/0x1150 fs/read_write.c:679 ksys_write+0x12b/0x250 fs/read_write.c:731 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: 0033:0x7f5ddbf8cd29 RSP: 002b:00007f5ddcd73038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f5ddc1a6080 RCX: 00007f5ddbf8cd29 RDX: 00000000fffffe28 RSI: 00000000200000c0 RDI: 0000000000000008 RBP: 00007f5ddc00e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5ddc1a6080 R15: 00007ffc57b50338 INFO: task syz.3.2464:12466 blocked for more than 144 seconds. Not tainted 6.13.0-syzkaller-08265-g9c5968db9e62 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.2464 state:D stack:27728 pid:12466 tgid:12464 ppid:5815 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6856 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6913 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730 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+0x735/0x1c40 fs/open.c:955 vfs_open+0x82/0x3f0 fs/open.c:1085 do_open fs/namei.c:3828 [inline] path_openat+0x1e88/0x2d80 fs/namei.c:3987 do_filp_open+0x20c/0x470 fs/namei.c:4014 do_sys_openat2+0x17a/0x1e0 fs/open.c:1427 do_sys_open fs/open.c:1442 [inline] __do_sys_openat fs/open.c:1458 [inline] __se_sys_openat fs/open.c:1453 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1453 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: 0033:0x7f610318cd29 RSP: 002b:00007f6103fbe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f61033a5fa0 RCX: 00007f610318cd29 RDX: 0000000000000000 RSI: 0000000020000040 RDI: ffffffffffffff9c RBP: 00007f610320e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f61033a5fa0 R15: 00007fff6e773308 Showing all locks held in the system: 2 locks held by kworker/u8:1/12: 1 lock held by khungtaskd/30: #0: ffffffff8e1be000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1be000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1be000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746 3 locks held by kworker/1:1/46: 2 locks held by kworker/1:2/116: 2 locks held by kworker/0:2/971: 2 locks held by kworker/u8:6/3479: 3 locks held by syslogd/5172: 2 locks held by dhcpcd/5483: 2 locks held by getty/5570: #0: ffff8880379690a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032fb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5812: 1 lock held by syz-executor/5822: 4 locks held by syz-executor/5823: 2 locks held by kworker/0:6/5873: 3 locks held by kworker/0:7/5896: 3 locks held by kworker/1:7/5921: 5 locks held by kworker/u8:10/8245: 2 locks held by kworker/u8:15/10140: 3 locks held by kworker/u8:16/10141: 4 locks held by syz.0.2458/12445: #0: ffff8880312170a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffff888031217130 (&tty->atomic_write_lock){+.+.}-{4:4}, at: tty_write_lock drivers/tty/tty_io.c:948 [inline] #1: ffff888031217130 (&tty->atomic_write_lock){+.+.}-{4:4}, at: iterate_tty_write drivers/tty/tty_io.c:967 [inline] #1: ffff888031217130 (&tty->atomic_write_lock){+.+.}-{4:4}, at: file_tty_write.constprop.0+0x281/0x9a0 drivers/tty/tty_io.c:1090 #2: ffff8880312172e8 (&tty->termios_rwsem){++++}-{4:4}, at: n_tty_write+0x1bd/0x1140 drivers/tty/n_tty.c:2372 #3: ffffc900211eb380 (&ldata->output_lock){+.+.}-{4:4}, at: process_output drivers/tty/n_tty.c:491 [inline] #3: ffffc900211eb380 (&ldata->output_lock){+.+.}-{4:4}, at: n_tty_write+0x4af/0x1140 drivers/tty/n_tty.c:2400 1 lock held by syz.3.2464/12466: #0: ffffffff8ee89908 (tty_mutex){+.+.}-{4:4}, at: ptmx_open drivers/tty/pty.c:823 [inline] #0: ffffffff8ee89908 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0xf6/0x350 drivers/tty/pty.c:790 1 lock held by syz-executor/12474: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-syzkaller-08265-g9c5968db9e62 #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: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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5921 Comm: kworker/1:7 Not tainted 6.13.0-syzkaller-08265-g9c5968db9e62 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events_long defense_work_handler RIP: 0010:stack_access_ok+0x25/0x200 arch/x86/kernel/unwind_orc.c:389 Code: 90 90 90 90 90 48 b8 00 00 00 00 00 fc ff df 41 57 41 56 4c 8d 77 08 41 55 41 54 49 89 d4 4c 89 f2 55 48 c1 ea 03 48 89 f5 53 <48> 89 fb 48 83 ec 08 80 3c 02 00 0f 85 94 01 00 00 4c 8d 6b 10 4c RSP: 0018:ffffc90000a17e80 EFLAGS: 00000a02 RAX: dffffc0000000000 RBX: 0000000000000002 RCX: ffffffff9193da4e RDX: 1ffff92000142fe6 RSI: ffffc90000a18868 RDI: ffffc90000a17f28 RBP: ffffc90000a18868 R08: ffffffff9193da84 R09: ffffffff9193da52 R10: ffffc90000a17f28 R11: 0000000000093188 R12: 0000000000000008 R13: ffffc90000a17f28 R14: ffffc90000a17f30 R15: ffffc90000a18868 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2a40600218 CR3: 00000000344aa000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline] unwind_next_frame+0xac7/0x20c0 arch/x86/kernel/unwind_orc.c:585 arch_stack_walk+0x95/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x226/0x3d0 mm/slub.c:4171 skb_clone+0x190/0x3f0 net/core/skbuff.c:2084 deliver_clone+0x3f/0xa0 net/bridge/br_forward.c:125 maybe_deliver+0xa7/0x120 net/bridge/br_forward.c:190 br_flood+0x17b/0x5e0 net/bridge/br_forward.c:237 br_handle_frame_finish+0xea2/0x1c90 net/bridge/br_input.c:220 br_nf_hook_thresh+0x303/0x410 net/bridge/br_netfilter_hooks.c:1170 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:508 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:282 [inline] br_handle_frame+0xad7/0x14a0 net/bridge/br_input.c:433 __netif_receive_skb_core.constprop.0+0xa20/0x4330 net/core/dev.c:5722 __netif_receive_skb_one_core+0xb1/0x1e0 net/core/dev.c:5826 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5941 process_backlog+0x443/0x15f0 net/core/dev.c:6289 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7106 napi_poll net/core/dev.c:7175 [inline] net_rx_action+0xa94/0x1010 net/core/dev.c:7297 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 local_bh_enable include/linux/bottom_half.h:33 [inline] update_defense_level+0x5ce/0xf50 net/netfilter/ipvs/ip_vs_ctl.c:210 defense_work_handler+0x26/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:235 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+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