Warning: Permanently added '10.128.1.194' (ED25519) to the list of known hosts. executing program [ 25.944935][ T6121] block nbd0: Receive control failed (result -107) [ 25.945104][ T52] block nbd0: Receive control failed (result -107) [ 25.992699][ T6525] nbd0: detected capacity change from 0 to 32 [ 25.994422][ T6526] [ 25.994784][ T6526] ====================================================== [ 25.995857][ T6526] WARNING: possible circular locking dependency detected [ 25.996789][ T6526] syzkaller #0 Not tainted [ 25.997450][ T6526] ------------------------------------------------------ [ 25.998488][ T6526] udevd/6526 is trying to acquire lock: [ 25.999282][ T6526] ffff0000da44b270 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_queue_rq+0x20c/0xc48 [ 26.000607][ T6526] [ 26.000607][ T6526] but task is already holding lock: [ 26.001749][ T6526] ffff0000d4d4e178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xb4/0xc48 [ 26.003037][ T6526] [ 26.003037][ T6526] which lock already depends on the new lock. [ 26.003037][ T6526] [ 26.004576][ T6526] [ 26.004576][ T6526] the existing dependency chain (in reverse order) is: [ 26.005999][ T6526] [ 26.005999][ T6526] -> #6 (&cmd->lock){+.+.}-{4:4}: [ 26.007068][ T6526] __mutex_lock_common+0x1d0/0x2678 [ 26.007919][ T6526] mutex_lock_nested+0x2c/0x38 [ 26.008782][ T6526] nbd_queue_rq+0xb4/0xc48 [ 26.009576][ T6526] blk_mq_dispatch_rq_list+0x890/0x1548 [ 26.010646][ T6526] __blk_mq_sched_dispatch_requests+0xa7c/0x10e4 [ 26.011728][ T6526] blk_mq_sched_dispatch_requests+0xa4/0x154 [ 26.012663][ T6526] blk_mq_run_hw_queue+0x2d0/0x4a4 [ 26.013552][ T6526] blk_mq_dispatch_list+0xa00/0xaf8 [ 26.014481][ T6526] blk_mq_flush_plug_list+0x3a4/0x488 [ 26.015436][ T6526] __blk_flush_plug+0x330/0x408 [ 26.016232][ T6526] __submit_bio+0x3f4/0x4d8 [ 26.016957][ T6526] submit_bio_noacct_nocheck+0x390/0xaac [ 26.017904][ T6526] submit_bio_noacct+0xc94/0x177c [ 26.018752][ T6526] submit_bio+0x3b4/0x550 [ 26.019566][ T6526] submit_bh_wbc+0x3ec/0x4bc [ 26.020391][ T6526] block_read_full_folio+0x734/0x824 [ 26.021237][ T6526] blkdev_read_folio+0x28/0x38 [ 26.022002][ T6526] filemap_read_folio+0xec/0x2f8 [ 26.022829][ T6526] do_read_cache_folio+0x364/0x5bc [ 26.023724][ T6526] read_cache_folio+0x68/0x88 [ 26.024506][ T6526] read_part_sector+0xcc/0x6fc [ 26.025294][ T6526] adfspart_check_ICS+0xa0/0x83c [ 26.026170][ T6526] bdev_disk_changed+0x674/0x11fc [ 26.027075][ T6526] blkdev_get_whole+0x2b0/0x4a4 [ 26.027910][ T6526] bdev_open+0x3b0/0xc20 [ 26.028689][ T6526] blkdev_open+0x364/0x4e8 [ 26.029468][ T6526] do_dentry_open+0x7a4/0x10bc [ 26.030304][ T6526] vfs_open+0x44/0x2d4 [ 26.030950][ T6526] path_openat+0x2424/0x2c40 [ 26.031762][ T6526] do_filp_open+0x18c/0x36c [ 26.032490][ T6526] do_sys_openat2+0x11c/0x1b4 [ 26.033284][ T6526] __arm64_sys_openat+0x120/0x158 [ 26.034147][ T6526] invoke_syscall+0x98/0x2b8 [ 26.035011][ T6526] el0_svc_common+0x130/0x23c [ 26.035887][ T6526] do_el0_svc+0x48/0x58 [ 26.036677][ T6526] el0_svc+0x5c/0x254 [ 26.037464][ T6526] el0t_64_sync_handler+0x84/0x12c [ 26.038370][ T6526] el0t_64_sync+0x198/0x19c [ 26.039118][ T6526] [ 26.039118][ T6526] -> #5 (set->srcu){.+.+}-{0:0}: [ 26.040310][ T6526] srcu_lock_sync+0x2c/0x38 [ 26.041125][ T6526] __synchronize_srcu+0xa0/0x348 [ 26.041937][ T6526] synchronize_srcu+0x2cc/0x338 [ 26.042748][ T6526] blk_mq_quiesce_queue+0x118/0x16c [ 26.043743][ T6526] elevator_switch+0x12c/0x410 [ 26.044630][ T6526] elevator_change+0x264/0x3cc [ 26.045455][ T6526] elevator_set_default+0x138/0x21c [ 26.046336][ T6526] blk_register_queue+0x2b4/0x338 [ 26.047221][ T6526] __add_disk+0x560/0xb90 [ 26.047956][ T6526] add_disk_fwnode+0xdc/0x438 [ 26.048698][ T6526] device_add_disk+0x38/0x4c [ 26.049510][ T6526] nbd_dev_add+0x560/0x820 [ 26.050337][ T6526] nbd_init+0x15c/0x174 [ 26.051074][ T6526] do_one_initcall+0x250/0x990 [ 26.051879][ T6526] do_initcall_level+0x128/0x1c4 [ 26.052796][ T6526] do_initcalls+0x70/0xd0 [ 26.053552][ T6526] do_basic_setup+0x78/0x8c [ 26.054334][ T6526] kernel_init_freeable+0x268/0x39c [ 26.055178][ T6526] kernel_init+0x24/0x1dc [ 26.055882][ T6526] ret_from_fork+0x10/0x20 [ 26.056600][ T6526] [ 26.056600][ T6526] -> #4 (&q->elevator_lock){+.+.}-{4:4}: [ 26.057829][ T6526] __mutex_lock_common+0x1d0/0x2678 [ 26.058671][ T6526] mutex_lock_nested+0x2c/0x38 [ 26.059447][ T6526] elevator_change+0x16c/0x3cc [ 26.060252][ T6526] elevator_set_none+0x48/0xac [ 26.061034][ T6526] blk_mq_update_nr_hw_queues+0x4c8/0x15f4 [ 26.061996][ T6526] nbd_start_device+0x158/0xa48 [ 26.062818][ T6526] nbd_genl_connect+0xf88/0x158c [ 26.063678][ T6526] genl_family_rcv_msg_doit+0x1d8/0x2bc [ 26.064632][ T6526] genl_rcv_msg+0x450/0x624 [ 26.065408][ T6526] netlink_rcv_skb+0x220/0x3fc [ 26.066149][ T6526] genl_rcv+0x38/0x50 [ 26.066810][ T6526] netlink_unicast+0x694/0x8c4 [ 26.067598][ T6526] netlink_sendmsg+0x648/0x930 [ 26.068413][ T6526] ____sys_sendmsg+0x490/0x7b8 [ 26.069282][ T6526] ___sys_sendmsg+0x204/0x278 [ 26.070121][ T6526] __arm64_sys_sendmsg+0x184/0x238 [ 26.070954][ T6526] invoke_syscall+0x98/0x2b8 [ 26.071674][ T6526] el0_svc_common+0x130/0x23c [ 26.072400][ T6526] do_el0_svc+0x48/0x58 [ 26.073188][ T6526] el0_svc+0x5c/0x254 [ 26.073874][ T6526] el0t_64_sync_handler+0x84/0x12c [ 26.074786][ T6526] el0t_64_sync+0x198/0x19c [ 26.075572][ T6526] [ 26.075572][ T6526] -> #3 (&q->q_usage_counter(io)#33){++++}-{0:0}: [ 26.076841][ T6526] blk_alloc_queue+0x48c/0x54c [ 26.077543][ T6526] __blk_mq_alloc_disk+0x124/0x304 [ 26.078427][ T6526] nbd_dev_add+0x398/0x820 [ 26.079202][ T6526] nbd_init+0x15c/0x174 [ 26.079971][ T6526] do_one_initcall+0x250/0x990 [ 26.080842][ T6526] do_initcall_level+0x128/0x1c4 [ 26.081657][ T6526] do_initcalls+0x70/0xd0 [ 26.082417][ T6526] do_basic_setup+0x78/0x8c [ 26.083170][ T6526] kernel_init_freeable+0x268/0x39c [ 26.084054][ T6526] kernel_init+0x24/0x1dc [ 26.084844][ T6526] ret_from_fork+0x10/0x20 [ 26.085651][ T6526] [ 26.085651][ T6526] -> #2 (fs_reclaim){+.+.}-{0:0}: [ 26.086784][ T6526] fs_reclaim_acquire+0x8c/0x118 [ 26.087627][ T6526] __kmalloc_cache_noprof+0x58/0x3fc [ 26.088463][ T6526] virtio_transport_do_socket_init+0x60/0x2b8 [ 26.089422][ T6526] vsock_assign_transport+0x514/0x65c [ 26.090371][ T6526] vsock_connect+0x4a8/0xb94 [ 26.091213][ T6526] __sys_connect+0x2a0/0x3ac [ 26.092020][ T6526] __arm64_sys_connect+0x7c/0x94 [ 26.092839][ T6526] invoke_syscall+0x98/0x2b8 [ 26.093604][ T6526] el0_svc_common+0x130/0x23c [ 26.094407][ T6526] do_el0_svc+0x48/0x58 [ 26.095136][ T6526] el0_svc+0x5c/0x254 [ 26.095818][ T6526] el0t_64_sync_handler+0x84/0x12c [ 26.096725][ T6526] el0t_64_sync+0x198/0x19c [ 26.097524][ T6526] [ 26.097524][ T6526] -> #1 (sk_lock-AF_VSOCK){+.+.}-{0:0}: [ 26.098753][ T6526] lock_sock_nested+0x58/0x118 [ 26.099585][ T6526] vsock_shutdown+0x70/0x280 [ 26.100346][ T6526] kernel_sock_shutdown+0x6c/0x80 [ 26.101153][ T6526] nbd_mark_nsock_dead+0x2a4/0x534 [ 26.102081][ T6526] recv_work+0x1cf8/0x2044 [ 26.102844][ T6526] process_one_work+0x7e8/0x155c [ 26.103688][ T6526] worker_thread+0x958/0xed8 [ 26.104421][ T6526] kthread+0x5fc/0x75c [ 26.105161][ T6526] ret_from_fork+0x10/0x20 [ 26.105874][ T6526] [ 26.105874][ T6526] -> #0 (&nsock->tx_lock){+.+.}-{4:4}: [ 26.106979][ T6526] __lock_acquire+0x1774/0x30a4 [ 26.107770][ T6526] lock_acquire+0x14c/0x2e0 [ 26.108551][ T6526] __mutex_lock_common+0x1d0/0x2678 [ 26.109476][ T6526] mutex_lock_nested+0x2c/0x38 [ 26.110377][ T6526] nbd_queue_rq+0x20c/0xc48 [ 26.111176][ T6526] blk_mq_dispatch_rq_list+0x890/0x1548 [ 26.112123][ T6526] __blk_mq_sched_dispatch_requests+0xa7c/0x10e4 [ 26.113157][ T6526] blk_mq_sched_dispatch_requests+0xa4/0x154 [ 26.114102][ T6526] blk_mq_run_hw_queue+0x2d0/0x4a4 [ 26.114959][ T6526] blk_mq_dispatch_list+0xa00/0xaf8 [ 26.115821][ T6526] blk_mq_flush_plug_list+0x3a4/0x488 [ 26.116889][ T6526] __blk_flush_plug+0x330/0x408 [ 26.117744][ T6526] __submit_bio+0x3f4/0x4d8 [ 26.118541][ T6526] submit_bio_noacct_nocheck+0x390/0xaac [ 26.119424][ T6526] submit_bio_noacct+0xc94/0x177c [ 26.120317][ T6526] submit_bio+0x3b4/0x550 [ 26.121070][ T6526] submit_bh_wbc+0x3ec/0x4bc [ 26.121784][ T6526] block_read_full_folio+0x734/0x824 [ 26.122588][ T6526] blkdev_read_folio+0x28/0x38 [ 26.123327][ T6526] filemap_read_folio+0xec/0x2f8 [ 26.124194][ T6526] do_read_cache_folio+0x364/0x5bc [ 26.125089][ T6526] read_cache_folio+0x68/0x88 [ 26.125855][ T6526] read_part_sector+0xcc/0x6fc [ 26.126676][ T6526] adfspart_check_ICS+0xa0/0x83c [ 26.127539][ T6526] bdev_disk_changed+0x674/0x11fc [ 26.128444][ T6526] blkdev_get_whole+0x2b0/0x4a4 [ 26.129236][ T6526] bdev_open+0x3b0/0xc20 [ 26.129991][ T6526] blkdev_open+0x364/0x4e8 [ 26.130821][ T6526] do_dentry_open+0x7a4/0x10bc [ 26.131584][ T6526] vfs_open+0x44/0x2d4 [ 26.132235][ T6526] path_openat+0x2424/0x2c40 [ 26.132918][ T6526] do_filp_open+0x18c/0x36c [ 26.133686][ T6526] do_sys_openat2+0x11c/0x1b4 [ 26.134443][ T6526] __arm64_sys_openat+0x120/0x158 [ 26.135248][ T6526] invoke_syscall+0x98/0x2b8 [ 26.136017][ T6526] el0_svc_common+0x130/0x23c [ 26.136824][ T6526] do_el0_svc+0x48/0x58 [ 26.137569][ T6526] el0_svc+0x5c/0x254 [ 26.138256][ T6526] el0t_64_sync_handler+0x84/0x12c [ 26.139112][ T6526] el0t_64_sync+0x198/0x19c [ 26.139926][ T6526] [ 26.139926][ T6526] other info that might help us debug this: [ 26.139926][ T6526] [ 26.141510][ T6526] Chain exists of: [ 26.141510][ T6526] &nsock->tx_lock --> set->srcu --> &cmd->lock [ 26.141510][ T6526] [ 26.143317][ T6526] Possible unsafe locking scenario: [ 26.143317][ T6526] [ 26.144378][ T6526] CPU0 CPU1 [ 26.145193][ T6526] ---- ---- [ 26.146047][ T6526] lock(&cmd->lock); [ 26.146701][ T6526] lock(set->srcu); [ 26.147731][ T6526] lock(&cmd->lock); [ 26.148793][ T6526] lock(&nsock->tx_lock); [ 26.149497][ T6526] [ 26.149497][ T6526] *** DEADLOCK *** [ 26.149497][ T6526] [ 26.150739][ T6526] 3 locks held by udevd/6526: [ 26.151453][ T6526] #0: ffff0000ca271358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xcc/0xc20 [ 26.152975][ T6526] #1: ffff0000c9e6dd90 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire+0x18/0x54 [ 26.154398][ T6526] #2: ffff0000d4d4e178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xb4/0xc48 [ 26.155737][ T6526] [ 26.155737][ T6526] stack backtrace: [ 26.156640][ T6526] CPU: 1 UID: 0 PID: 6526 Comm: udevd Not tainted syzkaller #0 PREEMPT [ 26.157834][ T6526] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025 [ 26.159237][ T6526] Call trace: [ 26.159700][ T6526] show_stack+0x2c/0x3c (C) [ 26.160370][ T6526] __dump_stack+0x30/0x40 [ 26.160974][ T6526] dump_stack_lvl+0xd8/0x12c [ 26.161749][ T6526] dump_stack+0x1c/0x28 [ 26.162427][ T6526] print_circular_bug+0x324/0x32c [ 26.163220][ T6526] check_noncircular+0x154/0x174 [ 26.163975][ T6526] __lock_acquire+0x1774/0x30a4 [ 26.164748][ T6526] lock_acquire+0x14c/0x2e0 [ 26.165471][ T6526] __mutex_lock_common+0x1d0/0x2678 [ 26.166255][ T6526] mutex_lock_nested+0x2c/0x38 [ 26.166946][ T6526] nbd_queue_rq+0x20c/0xc48 [ 26.167609][ T6526] blk_mq_dispatch_rq_list+0x890/0x1548 [ 26.168587][ T6526] __blk_mq_sched_dispatch_requests+0xa7c/0x10e4 [ 26.169542][ T6526] blk_mq_sched_dispatch_requests+0xa4/0x154 [ 26.170479][ T6526] blk_mq_run_hw_queue+0x2d0/0x4a4 [ 26.171332][ T6526] blk_mq_dispatch_list+0xa00/0xaf8 [ 26.172265][ T6526] blk_mq_flush_plug_list+0x3a4/0x488 [ 26.173199][ T6526] __blk_flush_plug+0x330/0x408 [ 26.174048][ T6526] __submit_bio+0x3f4/0x4d8 [ 26.174800][ T6526] submit_bio_noacct_nocheck+0x390/0xaac [ 26.175810][ T6526] submit_bio_noacct+0xc94/0x177c [ 26.176680][ T6526] submit_bio+0x3b4/0x550 [ 26.177362][ T6526] submit_bh_wbc+0x3ec/0x4bc [ 26.178153][ T6526] block_read_full_folio+0x734/0x824 [ 26.179053][ T6526] blkdev_read_folio+0x28/0x38 [ 26.179827][ T6526] filemap_read_folio+0xec/0x2f8 [ 26.180683][ T6526] do_read_cache_folio+0x364/0x5bc [ 26.181529][ T6526] read_cache_folio+0x68/0x88 [ 26.182316][ T6526] read_part_sector+0xcc/0x6fc [ 26.183108][ T6526] adfspart_check_ICS+0xa0/0x83c [ 26.183919][ T6526] bdev_disk_changed+0x674/0x11fc [ 26.184699][ T6526] blkdev_get_whole+0x2b0/0x4a4 [ 26.185479][ T6526] bdev_open+0x3b0/0xc20 [ 26.186182][ T6526] blkdev_open+0x364/0x4e8 [ 26.186977][ T6526] do_dentry_open+0x7a4/0x10bc [ 26.187677][ T6526] vfs_open+0x44/0x2d4 [ 26.188347][ T6526] path_openat+0x2424/0x2c40 [ 26.189196][ T6526] do_filp_open+0x18c/0x36c [ 26.189950][ T6526] do_sys_openat2+0x11c/0x1b4 [ 26.190693][ T6526] __arm64_sys_openat+0x120/0x158 [ 26.191504][ T6526] invoke_syscall+0x98/0x2b8 [ 26.192211][ T6526] el0_svc_common+0x130/0x23c [ 26.192921][ T6526] do_el0_svc+0x48/0x58 [ 26.193568][ T6526] el0_svc+0x5c/0x254 [ 26.194166][ T6526] el0t_64_sync_handler+0x84/0x12c [ 26.194979][ T6526] el0t_64_sync+0x198/0x19c [ 26.195972][ T6526] block nbd0: Dead connection, failed to find a fallback [ 26.195991][ T6526] block nbd0: shutting down sockets [ 26.196006][ T6526] I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 [ 26.196024][ T6526] Bu