INFO: task udevd:5465 blocked for more than 143 seconds. Not tainted 6.10.0-syzkaller-09703-gd7e78951a8b8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:20536 pid:5465 tgid:5465 ppid:4555 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 wait_for_reconnect drivers/block/nbd.c:1023 [inline] nbd_handle_cmd drivers/block/nbd.c:1065 [inline] nbd_queue_rq+0x7cd/0x2f70 drivers/block/nbd.c:1123 blk_mq_dispatch_rq_list+0xb89/0x1b30 block/blk-mq.c:2032 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline] __blk_mq_sched_dispatch_requests+0xb8a/0x1840 block/blk-mq-sched.c:309 blk_mq_sched_dispatch_requests+0xcb/0x140 block/blk-mq-sched.c:331 blk_mq_run_hw_queue+0x576/0xae0 block/blk-mq.c:2245 blk_mq_flush_plug_list+0x1115/0x1880 block/blk-mq.c:2794 __blk_flush_plug+0x420/0x500 block/blk-core.c:1195 blk_finish_plug block/blk-core.c:1222 [inline] __submit_bio+0x422/0x560 block/blk-core.c:623 __submit_bio_noacct_mq block/blk-core.c:696 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:725 submit_bh fs/buffer.c:2829 [inline] block_read_full_folio+0x93b/0xcd0 fs/buffer.c:2456 filemap_read_folio+0x1a0/0x790 mm/filemap.c:2355 do_read_cache_folio+0x134/0x820 mm/filemap.c:3789 read_mapping_folio include/linux/pagemap.h:913 [inline] read_part_sector+0xb3/0x330 block/partitions/core.c:712 adfspart_check_ICS+0xd9/0x9a0 block/partitions/acorn.c:360 check_partition block/partitions/core.c:138 [inline] blk_add_partitions block/partitions/core.c:579 [inline] bdev_disk_changed+0x72c/0x13d0 block/partitions/core.c:683 blkdev_get_whole+0x2d2/0x450 block/bdev.c:700 bdev_open+0x2d4/0xc60 block/bdev.c:909 blkdev_open+0x3e8/0x570 block/fops.c:630 do_dentry_open+0x970/0x1440 fs/open.c:959 vfs_open+0x3e/0x330 fs/open.c:1089 do_open fs/namei.c:3727 [inline] path_openat+0x2b3e/0x3470 fs/namei.c:3886 do_filp_open+0x235/0x490 fs/namei.c:3913 do_sys_openat2+0x13e/0x1d0 fs/open.c:1416 do_sys_open fs/open.c:1431 [inline] __do_sys_openat fs/open.c:1447 [inline] __se_sys_openat fs/open.c:1442 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1442 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: 0033:0x7f7e8a1169a4 RSP: 002b:00007ffc12624b10 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00005614b380f550 RCX: 00007f7e8a1169a4 RDX: 00000000000a0800 RSI: 00005614b380ec90 RDI: 00000000ffffff9c RBP: 00005614b380ec90 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000a0800 R13: 00005614b37fba70 R14: 0000000000000001 R15: 00005614b37ea910 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: 3 locks held by kworker/u8:1/12: #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90000117d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc90000117d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8e33c1f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:328 [inline] #2: ffffffff8e33c1f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:958 1 lock held by khungtaskd/30: #0: ffffffff8e336e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:327 [inline] #0: ffffffff8e336e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:839 [inline] #0: ffffffff8e336e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6620 2 locks held by kworker/u8:5/1036: #0: ffff8880b953e858 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:560 #1: ffff8880b9528948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x441/0x770 kernel/sched/psi.c:989 2 locks held by kworker/u8:6/1087: 5 locks held by kworker/u8:8/1104: #0: ffff888015edd948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff888015edd948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90004557d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc90004557d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8f5f1b90 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:594 #3: ffff88807c965428 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_destruct+0x110/0x2e0 drivers/net/wireguard/device.c:249 #4: ffffffff8e33c0c0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4486 1 lock held by syslogd/4537: #0: ffff8880b943e858 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:560 1 lock held by dhcpcd/4769: #0: ffffffff8f5fe708 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2ce/0x1bc0 net/ipv4/devinet.c:1101 2 locks held by getty/4862: #0: ffff88802f7f80a0 (&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+0x6b5/0x1e10 drivers/tty/n_tty.c:2211 3 locks held by udevd/5310: #0: ffff888020c0a4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xf0/0xc60 block/bdev.c:897 #1: ffff88801f06bc10 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:151 [inline] #1: ffff88801f06bc10 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:250 [inline] #1: ffff88801f06bc10 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x54d/0xae0 block/blk-mq.c:2245 #2: ffff888020de8180 (&cmd->lock){+.+.}-{3:3}, at: nbd_queue_rq+0xfc/0x2f70 drivers/block/nbd.c:1115 3 locks held by udevd/5465: #0: ffff8880203c64c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xf0/0xc60 block/bdev.c:897 #1: ffff88801f06b590 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:151 [inline] #1: ffff88801f06b590 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:250 [inline] #1: ffff88801f06b590 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x54d/0xae0 block/blk-mq.c:2245 #2: ffff888020c98180 (&cmd->lock){+.+.}-{3:3}, at: nbd_queue_rq+0xfc/0x2f70 drivers/block/nbd.c:1115 8 locks held by syz-executor/8391: #0: ffff88802adac420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2876 [inline] #0: ffff88802adac420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x227/0xc90 fs/read_write.c:586 #1: ffff88802a1a1088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x500 fs/kernfs/file.c:325 #2: ffff88801c360788 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x500 fs/kernfs/file.c:326 #3: ffffffff8ef09528 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 #4: ffff88806554a0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff88806554a0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1093 [inline] #4: ffff88806554a0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1290 #5: ffff888065549250 (&devlink->lock_key#19){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1672 #6: ffffffff8f5fe708 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x71/0x5c0 drivers/net/netdevsim/netdev.c:773 #7: ffffffff8e33c1f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:296 [inline] #7: ffffffff8e33c1f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:958 1 lock held by syz.4.702/8530: #0: ffffffff8e33c0c0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4486 1 lock held by syz.2.704/8537: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 30 Comm: khungtaskd Not tainted 6.10.0-syzkaller-09703-gd7e78951a8b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 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+0xfde/0x1020 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 19 Comm: rcu_exp_gp_kthr Not tainted 6.10.0-syzkaller-09703-gd7e78951a8b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:__lock_acquire+0x452/0x2040 kernel/locking/lockdep.c:5081 Code: 95 c0 31 c9 83 3f 00 0f 95 c1 09 cb c1 e3 0d 44 09 c3 8b 4c 24 54 c1 e1 0f 0f b7 c9 09 d9 8b 7c 24 68 83 e7 03 c1 e7 10 09 cf <8b> 4c 24 60 83 e1 01 c1 e1 12 c1 e0 14 31 d2 83 7c 24 40 00 0f 95 RSP: 0018:ffffc900001879b0 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 0000000000000044 RCX: 0000000000000044 RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000044 RBP: 0000000000000000 R08: 0000000000000044 R09: ffff8880176dc6e0 R10: dffffc0000000000 R11: fffffbfff1f5e15e R12: ffff8880176dbc00 R13: 0000000000000044 R14: 0000000000000000 R15: ffffffff8e33ba98 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020548030 CR3: 0000000069b3c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 sync_exp_reset_tree kernel/rcu/tree_exp.h:140 [inline] sync_rcu_exp_select_cpus kernel/rcu/tree_exp.h:500 [inline] rcu_exp_sel_wait_wake+0x109/0x1db0 kernel/rcu/tree_exp.h:691 kthread_worker_fn+0x500/0xaf0 kernel/kthread.c:842 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