INFO: task syz-executor.3:3806 blocked for more than 143 seconds. Not tainted 6.0.0-syzkaller-06475-g4c86114194e6 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:26112 pid: 3806 ppid: 3641 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5183 [inline] __schedule+0x957/0xe20 kernel/sched/core.c:6495 schedule+0xcb/0x190 kernel/sched/core.c:6571 schedule_timeout+0xac/0x300 kernel/time/timer.c:1911 do_wait_for_common+0x3ea/0x560 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x46/0x60 kernel/sched/completion.c:138 __flush_work+0x124/0x1a0 kernel/workqueue.c:3073 __cancel_work_timer+0x517/0x6a0 kernel/workqueue.c:3160 p9_conn_destroy net/9p/trans_fd.c:890 [inline] p9_fd_close+0x2c5/0x410 net/9p/trans_fd.c:920 p9_client_destroy+0xc8/0x610 net/9p/client.c:1018 v9fs_session_init+0x1453/0x1990 fs/9p/v9fs.c:488 v9fs_mount+0xd2/0xcb0 fs/9p/vfs_super.c:126 legacy_get_tree+0xea/0x180 fs/fs_context.c:610 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x289/0xad0 fs/namespace.c:3040 do_mount fs/namespace.c:3383 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3568 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fb52408a5a9 RSP: 002b:00007fb525281168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fb5241ac050 RCX: 00007fb52408a5a9 RDX: 0000000020000140 RSI: 0000000020000400 RDI: 0000000000000000 RBP: 00007fb5240e5580 R08: 0000000020000480 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd1ae0230f R14: 00007fb525281300 R15: 0000000000022000 Showing all locks held in the system: 4 locks held by kworker/u4:0/9: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8cd1f1b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/14: #0: ffffffff8cd1f9b0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/29: #0: ffffffff8cd1efe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 1 lock held by udevd/2975: 2 locks held by getty/3291: #0: ffff8880174f1098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6e8/0x1e50 drivers/tty/n_tty.c:2177 2 locks held by kworker/0:7/3758: #0: ffff888012064d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262 #1: ffffc90004827d00 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264 5 locks held by syz-executor.1/5734: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.0.0-syzkaller-06475-g4c86114194e6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x47c/0x4b0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x169/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xcd5/0xd20 kernel/hung_task.c:369 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3923 Comm: syz-executor.3 Not tainted 6.0.0-syzkaller-06475-g4c86114194e6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:check_preemption_disabled+0x58/0x120 lib/smp_processor_id.c:19 Code: 65 48 8b 04 25 28 00 00 00 48 3b 44 24 08 0f 85 cc 00 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5e 41 5f c3 48 c7 04 24 00 00 00 00 <9c> 8f 04 24 f7 04 24 00 02 00 00 74 c9 49 89 f6 49 89 ff 65 4c 8b RSP: 0018:ffffc90005a47e48 EFLAGS: 00000046 RAX: 0000000080000000 RBX: 0000000000000000 RCX: 1ffffffff1f37600 RDX: 1ffffffff1f37600 RSI: ffffffff8b0a9640 RDI: ffffffff8b0a9600 RBP: 000000000000122c R08: ffffffff8f9bb000 R09: ffffffff8f9bb008 R10: ffffffff8f9bb018 R11: ffffffff8f9bb010 R12: ffff888079cfd880 R13: dffffc0000000000 R14: 00000000090d742a R15: 000000000000122c FS: 00005555558e2400(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c012e97000 CR3: 000000008277c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: steal_account_process_time kernel/sched/cputime.c:256 [inline] account_other_time+0x135/0x280 kernel/sched/cputime.c:276 get_vtime_delta kernel/sched/cputime.c:671 [inline] vtime_account_system kernel/sched/cputime.c:681 [inline] vtime_user_enter+0xfd/0x2d0 kernel/sched/cputime.c:725 __ct_user_enter+0xab/0x130 kernel/context_tracking.c:489 user_enter_irqoff include/linux/context_tracking.h:42 [inline] __exit_to_user_mode kernel/entry/common.c:132 [inline] syscall_exit_to_user_mode+0x5d/0x60 kernel/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f0acc4af2d1 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 aa e7 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 e3 e7 ff ff 48 8b 04 24 eb 97 66 2e 0f 1f RSP: 002b:00007ffc63914f30 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 0000000000000119 RCX: 00007f0acc4af2d1 RDX: 00007ffc63914f70 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffc63914ffc R08: 0000000000000000 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032 R13: 0000000000051e2b R14: 0000000000000004 R15: 00007ffc63915060