INFO: task syz-executor.0:6190 blocked for more than 143 seconds. Not tainted 6.14.0-rc3-syzkaller-g2408a807bfc3 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27504 pid:6190 tgid:6188 ppid:6124 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x3e1/0x600 kernel/sched/completion.c:116 __flush_workqueue+0x3dc/0x1260 kernel/workqueue.c:3998 nbd_start_device_ioctl drivers/block/nbd.c:1541 [inline] __nbd_ioctl drivers/block/nbd.c:1602 [inline] nbd_ioctl+0x308/0xd60 drivers/block/nbd.c:1642 blkdev_ioctl+0x276/0x6d0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 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: 0033:0x7f5bd867cda9 RSP: 002b:00007f5bd93ae0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5bd87abf80 RCX: 00007f5bd867cda9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f5bd86c947a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f5bd87abf80 R15: 00007ffdefe96968 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746 2 locks held by kworker/u9:0/54: #0: ffff888025ff5948 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc90000bf7d18 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 2 locks held by getty/5572: #0: ffff88814d7a20a0 (&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 3 locks held by syz-executor.0/11296: #0: ffff888025ff1998 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x151/0xd60 drivers/block/nbd.c:1635 #1: ffff888025f25358 (&q->q_usage_counter(io)#49){+.+.}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x15/0x20 block/blk-mq.c:215 #2: ffff888025f25390 (&q->q_usage_counter(queue)#33){+.+.}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x15/0x20 block/blk-mq.c:215 1 lock held by syz-executor.0/11297: #0: ffff888025ff1998 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x151/0xd60 drivers/block/nbd.c:1635 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc3-syzkaller-g2408a807bfc3 #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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11296 Comm: syz-executor.0 Not tainted 6.14.0-rc3-syzkaller-g2408a807bfc3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:410 Code: 74 79 fc 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1a 66 03 5d 40 89 da ec <5b> 0f b6 c0 5d 41 5c c3 cc cc cc cc e8 98 8e dc fc eb a2 e8 21 8f RSP: 0018:ffffc900050ff5f8 EFLAGS: 00000002 RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: ffffffff85406a90 RDI: ffffffff9ab80740 RBP: ffffffff9ab80700 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000007 R12: 0000000000000000 R13: 0000000000000020 R14: fffffbfff357013a R15: dffffc0000000000 FS: 00007fc0a4fb56c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc0a4f94d58 CR3: 00000000251c6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr+0x137/0x210 drivers/tty/serial/8250/8250_port.c:2100 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3357 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3380 [inline] serial8250_console_write+0xf6c/0x1870 drivers/tty/serial/8250/8250_port.c:3465 console_emit_next_record kernel/printk/printk.c:3122 [inline] console_flush_all+0x800/0xc60 kernel/printk/printk.c:3210 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3309 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2432 dev_vprintk_emit drivers/base/core.c:4890 [inline] dev_printk_emit+0xfb/0x140 drivers/base/core.c:4901 __dev_printk+0xf5/0x270 drivers/base/core.c:4913 _dev_err+0xe5/0x120 drivers/base/core.c:4956 nbd_add_socket+0x778/0xbe0 drivers/block/nbd.c:1260 __nbd_ioctl drivers/block/nbd.c:1585 [inline] nbd_ioctl+0x8bd/0xd60 drivers/block/nbd.c:1642 blkdev_ioctl+0x276/0x6d0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 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: 0033:0x7fc0a427cda9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc0a4fb50c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc0a43abf80 RCX: 00007fc0a427cda9 RDX: 0000000000000004 RSI: 000000000000ab00 RDI: 0000000000000003 RBP: 00007fc0a42c947a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc0a43abf80 R15: 00007fff8c48bd18