INFO: task syz.5.11178:8274 blocked for more than 144 seconds. Not tainted 6.14.0-rc6-syzkaller-00016-g0fed89a961ea #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.11178 state:D stack:28368 pid:8274 tgid:8254 ppid:7735 task_flags:0x400640 flags:0x00000004 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 wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:264 coredump_wait fs/coredump.c:419 [inline] do_coredump+0x86f/0x4410 fs/coredump.c:576 get_signal+0x230b/0x26c0 kernel/signal.c:3021 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6d6f98d169 RSP: 002b:00007f6d7086d0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 00000000000000ca RBX: 00007f6d6fba6168 RCX: 00007f6d6f98d169 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f6d6fba616c RBP: 00007f6d6fba6160 R08: 00007f6d708b0000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6d6fba616c R13: 0000000000000000 R14: 00007ffee87d2070 R15: 00007ffee87d2158 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746 2 locks held by getty/5569: #0: ffff8880368500a0 (&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 1 lock held by syz.7.4835/20145: #0: ffffffff8fef8b68 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fef8b68 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3517 2 locks held by kworker/0:2/26837: #0: ffff88801b078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc900053b7d18 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 1 lock held by syz.1.9826/3754: 1 lock held by syz.8.9828/3760: #0: ffffffff8e1c85b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:334 3 locks held by kworker/u8:11/6360: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc90004af7d18 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8fef8b68 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:285 3 locks held by kworker/u8:13/6362: 5 locks held by kworker/u8:15/6371: 3 locks held by kworker/1:3/8651: #0: ffff88801b078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc9000ccd7d18 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8e1c85b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:334 7 locks held by syz-executor/9612: #0: ffff888036c62420 (sb_writers#9){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731 #1: ffff88805d370088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x27b/0x500 fs/kernfs/file.c:325 #2: ffff888027629698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x29e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f4a2b48 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd2/0x4b0 drivers/net/netdevsim/bus.c:216 #4: ffff88805c32f0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #4: ffff88805c32f0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88805c32f0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1293 #5: ffff88807c550250 (&devlink->lock_key#2){+.+.}-{4:4}, at: nsim_drv_remove+0x4a/0x1d0 drivers/net/netdevsim/dev.c:1675 #6: ffffffff8fef8b68 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x9d/0x710 drivers/net/netdevsim/netdev.c:1016 1 lock held by syz.7.11551/9767: #0: ffffffff8fef8b68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fef8b68 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x372/0xea0 net/core/rtnetlink.c:6918 1 lock held by syz.7.11551/9770: #0: ffffffff8fef8b68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fef8b68 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x372/0xea0 net/core/rtnetlink.c:6918 1 lock held by syz.0.11554/9773: #0: ffffffff8fef8b68 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fef8b68 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3517 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller-00016-g0fed89a961ea #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111