INFO: task udevd:5115 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:21400 pid:5115 tgid:5115 ppid:1 flags:0x00004002 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: 0033:0x7fdde8b169a4 RSP: 002b:00007ffc50eaaad0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000557023686e10 RCX: 00007fdde8b169a4 RDX: 00000000000a0800 RSI: 0000557023688b00 RDI: 00000000ffffff9c RBP: 0000557023688b00 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000a0800 R13: 000055702367a540 R14: 0000000000000001 R15: 0000557023665910 Showing all locks held in the system: 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 5 locks held by kworker/u8:8/1103: 2 locks held by getty/4857: #0: ffff88802aa3b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2211 3 locks held by udevd/5115: #0: ffff88802017a4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xf0/0xc60 block/bdev.c:897 #1: ffff88801fce1890 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:151 [inline] #1: ffff88801fce1890 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:250 [inline] #1: ffff88801fce1890 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x54d/0xae0 block/blk-mq.c:2245 #2: ffff8880201e0180 (&cmd->lock){+.+.}-{3:3}, at: nbd_queue_rq+0xfc/0x2f70 drivers/block/nbd.c:1115 3 locks held by udevd/6045: #0: ffff8880202764c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xf0/0xc60 block/bdev.c:897 #1: ffff88801b3b7a10 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:151 [inline] #1: ffff88801b3b7a10 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:250 [inline] #1: ffff88801b3b7a10 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x54d/0xae0 block/blk-mq.c:2245 #2: ffff888020358180 (&cmd->lock){+.+.}-{3:3}, at: nbd_queue_rq+0xfc/0x2f70 drivers/block/nbd.c:1115 2 locks held by kworker/u8:16/6149: 1 lock held by syz.2.1023/8486: 1 lock held by syz.1.1032/8511: ============================================= NMI backtrace for cpu 0 CPU: 0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8486 Comm: syz.2.1023 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_release+0x5/0xa30 kernel/locking/lockdep.c:5767 Code: 8f e8 af e3 89 00 e9 f1 f5 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 00 01 00 RSP: 0018:ffffc90002f3f678 EFLAGS: 00000286 RAX: ffffffff8952a7ac RBX: ffff88801e8721c0 RCX: 0000000000040000 RDX: ffffc90016601000 RSI: ffffffff8a7c5905 RDI: ffff88801e8721d8 RBP: ffffc90002f3f850 R08: ffffffff92ff0747 R09: 1ffffffff25fe0e8 R10: dffffc0000000000 R11: fffffbfff25fe0e9 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff8a7c5905 R15: ffff88801e872000 FS: 00007fcd51cc26c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020ca3030 CR3: 000000001f5a2000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:165 [inline] _raw_spin_unlock_bh+0x1b/0x40 kernel/locking/spinlock.c:210 bt_sock_stream_recvmsg+0x1415/0x1670 net/bluetooth/af_bluetooth.c:482 rfcomm_sock_recvmsg+0xea/0x280 net/bluetooth/rfcomm/sock.c:606 sock_recvmsg_nosec+0x18e/0x1d0 net/socket.c:1046 ____sys_recvmsg+0x3c0/0x470 net/socket.c:2814 ___sys_recvmsg net/socket.c:2858 [inline] do_recvmmsg+0x474/0xae0 net/socket.c:2952 __sys_recvmmsg net/socket.c:3031 [inline] __do_sys_recvmmsg net/socket.c:3054 [inline] __se_sys_recvmmsg net/socket.c:3047 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3047 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: 0033:0x7fcd50f75f19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcd51cc2048 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fcd51105f60 RCX: 00007fcd50f75f19 RDX: 000000000400023c RSI: 00000000200055c0 RDI: 0000000000000007 RBP: 00007fcd50fe4e68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fcd51105f60 R15: 00007ffdb3bc0838