INFO: task syz.4.1101:11931 blocked for more than 144 seconds. Not tainted 6.11.0-next-20240927-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1101 state:D stack:23808 pid:11931 tgid:11931 ppid:11315 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_timeout+0xb0/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 __vhost_worker_flush+0x1e6/0x280 drivers/vhost/vhost.c:288 vhost_worker_flush drivers/vhost/vhost.c:295 [inline] vhost_dev_flush+0xc9/0x150 drivers/vhost/vhost.c:305 vhost_net_flush+0x24/0x160 drivers/vhost/net.c:1359 vhost_net_release+0x109/0x470 drivers/vhost/net.c:1380 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f11e9f7dff9 RSP: 002b:00007ffd244eacb8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f11ea137a80 RCX: 00007f11e9f7dff9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f11ea137a80 R08: 0000000000000006 R09: 00007ffd244eafaf R10: 00000000003ffbbc R11: 0000000000000246 R12: 00000000000bd51a R13: 00007ffd244eadc0 R14: 0000000000000032 R15: ffffffffffffffff Showing all locks held in the system: 6 locks held by kworker/u8:1/12: 1 lock held by khungtaskd/30: #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 3 locks held by kworker/u8:2/35: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000ab7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000ab7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd3308 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 2 locks held by getty/4992: #0: ffff88803238a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/12877: #0: ffffffff8fcd3308 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcd3308 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 1 lock held by syz-executor/12880: #0: ffffffff8fcd3308 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcd3308 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 1 lock held by syz-executor/12884: #0: ffffffff8fcd3308 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcd3308 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 1 lock held by syz-executor/12887: #0: ffffffff8fcd3308 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcd3308 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 1 lock held by syz-executor/12905: #0: ffffffff8fcd3308 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcd3308 (rtnl_mutex){+.+.}-{3:3}, at: __rtnl_newlink net/core/rtnetlink.c:3720 [inline] #0: ffffffff8fcd3308 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_newlink+0xab7/0x20a0 net/core/rtnetlink.c:3743 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-next-20240927-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 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+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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: 12849 Comm: syz.0.1261 Not tainted 6.11.0-next-20240927-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__rb_erase_color+0x4/0xa30 lib/rbtree.c:412 Code: e9 74 fe ff ff e8 3c a0 07 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <55> 41 57 41 56 41 55 41 54 53 48 83 ec 30 48 89 54 24 18 48 89 74 RSP: 0000:ffffc900036e7468 EFLAGS: 00000086 RAX: 1ffff110082d9792 RBX: ffff8880416cbcb0 RCX: dffffc0000000000 RDX: ffffffff81684d00 RSI: ffff8880b873eb88 RDI: ffff8880416cbc90 RBP: 0000000000000000 R08: ffff8880b873f89f R09: 0000000000000000 R10: ffff8880b873f890 R11: ffffffff81675800 R12: ffff8880416cbcb8 R13: ffff88807aaa80b8 R14: dffffc0000000000 R15: 0000000000000000 FS: 00007f3c3b6c86c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020e2d000 CR3: 000000007ab18000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rb_erase_augmented include/linux/rbtree_augmented.h:331 [inline] rb_erase_augmented_cached include/linux/rbtree_augmented.h:340 [inline] __dequeue_entity+0x953/0xd30 kernel/sched/fair.c:863 set_next_entity+0xfe/0x4c0 kernel/sched/fair.c:5572 set_next_task_fair+0x7c/0x570 kernel/sched/fair.c:13254 put_prev_set_next_task kernel/sched/sched.h:2482 [inline] pick_next_task kernel/sched/core.c:6250 [inline] __schedule+0x428a/0x4b30 kernel/sched/core.c:6629 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_timeout+0xb0/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 rdmsr_safe_on_cpu+0x16c/0x310 arch/x86/lib/msr-smp.c:181 msr_read+0x15d/0x260 arch/x86/kernel/msr.c:66 vfs_read+0x201/0xbc0 fs/read_write.c:567 ksys_read+0x183/0x2b0 fs/read_write.c:712 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3c3a97dff9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3c3b6c8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f3c3ab35f80 RCX: 00007f3c3a97dff9 RDX: 7706c522012798af RSI: 0000000020001340 RDI: 0000000000000005 RBP: 00007f3c3a9f0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3c3ab35f80 R15: 00007ffd1ae9c968