INFO: task syz-executor.0:6152 blocked for more than 143 seconds. Not tainted 6.12.0-rc6-syzkaller-00279-gde2f378f2b77 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:25648 pid:6152 tgid:6151 ppid:6129 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0xe55/0x5740 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 schedule_timeout+0x258/0x2a0 kernel/time/timer.c:2591 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x3e1/0x600 kernel/sched/completion.c:116 __flush_workqueue+0x39e/0x1200 kernel/workqueue.c:3973 nbd_start_device_ioctl drivers/block/nbd.c:1478 [inline] __nbd_ioctl drivers/block/nbd.c:1539 [inline] nbd_ioctl+0x308/0xfd0 drivers/block/nbd.c:1579 blkdev_ioctl+0x276/0x6d0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18f/0x220 fs/ioctl.c:893 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: 0033:0x456e69 RSP: 002b:00007fb03d2fd0d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000055bf80 RCX: 0000000000456e69 RDX: ffffffffffffffff RSI: 000000000000ab03 RDI: 0000000000000005 RBP: 00000000004b0cab R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004b02b7 R13: 000000000000000b R14: 000000000055bf80 R15: 00007fff61abf038 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e1b8340 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1b8340 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1b8340 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 2 locks held by kworker/u9:1/5138: #0: ffff88802605d148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90010527d80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 2 locks held by getty/5586: #0: ffff8880361420a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032532f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00279-gde2f378f2b77 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 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:223 [inline] watchdog+0xf0c/0x1240 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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: 70 Comm: kworker/u8:4 Not tainted 6.12.0-rc6-syzkaller-00279-gde2f378f2b77 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Workqueue: 0x0 (events_unbound) RIP: 0010:calc_delta_fair kernel/sched/fair.c:291 [inline] RIP: 0010:place_entity+0x92/0x3e0 kernel/sched/fair.c:5273 Code: 48 c1 ea 03 80 3c 02 00 0f 85 0b 03 00 00 4c 8b ab 80 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 80 3c 02 00 <0f> 85 05 03 00 00 48 81 3b 00 00 10 00 0f 85 66 02 00 00 48 8d 7d RSP: 0018:ffffc900020bf718 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff888032f38080 RCX: 1ffff110039f692a RDX: 1ffff110065e7010 RSI: ffff888032f38080 RDI: ffff888032f38100 RBP: ffff8880b873ef40 R08: 0000000000000000 R09: fffffbfff20beb19 R10: ffffffff905f58cf R11: 0000000000000000 R12: 000001fa0759ef57 R13: 000000000016e360 R14: 0000000000000048 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560656e17600 CR3: 000000000df7c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: enqueue_entity+0xfa/0x14a0 kernel/sched/fair.c:5418 enqueue_task_fair+0x2ff/0xfb0 kernel/sched/fair.c:7003 enqueue_task+0x78/0x3e0 kernel/sched/core.c:2020 activate_task+0x54/0xd0 kernel/sched/core.c:2067 attach_task+0x116/0x1b0 kernel/sched/fair.c:9641 attach_tasks kernel/sched/fair.c:9676 [inline] sched_balance_rq+0x1456/0x2ec0 kernel/sched/fair.c:11753 sched_balance_newidle+0x6bb/0x1190 kernel/sched/fair.c:12795 pick_next_task_fair+0x50/0x1280 kernel/sched/fair.c:8943 __pick_next_task+0xf1/0x6c0 kernel/sched/core.c:5968 pick_next_task kernel/sched/core.c:6066 [inline] __schedule+0x42c/0x5740 kernel/sched/core.c:6644 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 worker_thread+0x2de/0xf00 kernel/workqueue.c:3406 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244