INFO: task syz.1.3054:22540 blocked for more than 143 seconds. Not tainted 6.12.0-rc2-syzkaller-00061-gb983b271662b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.3054 state:D stack:27424 pid:22540 tgid:22535 ppid:19875 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6774 blk_mq_freeze_queue_wait+0xff/0x190 block/blk-mq.c:139 nbd_add_socket+0x1a5/0x8f0 drivers/block/nbd.c:1189 __nbd_ioctl drivers/block/nbd.c:1522 [inline] nbd_ioctl+0x5c3/0xf40 drivers/block/nbd.c:1579 blkdev_ioctl+0x57d/0x6a0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 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: 0033:0x7f26a0f7dff9 RSP: 002b:00007f26a09de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f26a1136130 RCX: 00007f26a0f7dff9 RDX: 0000000000000005 RSI: 000000000000ab00 RDI: 0000000000000009 RBP: 00007f26a0ff0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f26a1136130 R15: 00007ffc6b5227b8 INFO: task syz.1.3054:22542 blocked for more than 143 seconds. Not tainted 6.12.0-rc2-syzkaller-00061-gb983b271662b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.3054 state:D stack:27424 pid:22542 tgid:22535 ppid:19875 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 nbd_ioctl+0x13c/0xf40 drivers/block/nbd.c:1572 blkdev_ioctl+0x57d/0x6a0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 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: 0033:0x7f26a0f7dff9 RSP: 002b:00007f26a09bd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f26a1136208 RCX: 00007f26a0f7dff9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004 RBP: 00007f26a0ff0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f26a1136208 R15: 00007ffc6b5227b8 INFO: task syz.1.3054:22543 blocked for more than 144 seconds. Not tainted 6.12.0-rc2-syzkaller-00061-gb983b271662b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.3054 state:D stack:27424 pid:22543 tgid:22535 ppid:19875 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 nbd_ioctl+0x13c/0xf40 drivers/block/nbd.c:1572 blkdev_ioctl+0x57d/0x6a0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 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: 0033:0x7f26a0f7dff9 RSP: 002b:00007f26a099c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f26a11362e0 RCX: 00007f26a0f7dff9 RDX: 0000000000000000 RSI: 000000000000ab04 RDI: 0000000000000009 RBP: 00007f26a0ff0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f26a11362e0 R15: 00007ffc6b5227b8 Showing all locks held in the system: 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 2 locks held by getty/4995: #0: ffff88802ed5f0a0 (&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.1.3054/22540: #0: ffff8880251ea198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x13c/0xf40 drivers/block/nbd.c:1572 1 lock held by syz.1.3054/22542: #0: ffff8880251ea198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x13c/0xf40 drivers/block/nbd.c:1572 1 lock held by syz.1.3054/22543: #0: ffff8880251ea198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x13c/0xf40 drivers/block/nbd.c:1572 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc2-syzkaller-00061-gb983b271662b #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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111