All of lore.kernel.org
 help / color / mirror / Atom feed
From: syzbot <syzbot+3dbc6142c85cc77eaf04@syzkaller.appspotmail.com>
To: axboe@kernel.dk, bvanassche@acm.org, hdanton@sina.com,
	 josef@toxicpanda.com, linux-block@vger.kernel.org,
	 linux-kernel@vger.kernel.org, ming.lei@redhat.com,
	nbd@other.debian.org,  penguin-kernel@i-love.sakura.ne.jp,
	syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [nbd?] possible deadlock in nbd_queue_rq
Date: Sun, 14 Sep 2025 19:16:27 -0700	[thread overview]
Message-ID: <68c776fb.050a0220.2ff435.0387.GAE@google.com> (raw)
In-Reply-To: <686aa557.a00a0220.c7b3.005d.GAE@google.com>

syzbot has found a reproducer for the following issue on:

HEAD commit:    8736259279a3 Merge branch 'for-next/core' into for-kernelci
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=11e2bb62580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9ed0a6d7c80843e9
dashboard link: https://syzkaller.appspot.com/bug?extid=3dbc6142c85cc77eaf04
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=178df642580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=148e7934580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/025c082a7762/disk-87362592.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/606f903fe4d2/vmlinux-87362592.xz
kernel image: https://storage.googleapis.com/syzbot-assets/23ea2634f398/Image-87362592.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3dbc6142c85cc77eaf04@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
udevd/6531 is trying to acquire lock:
ffff0001ffb32070 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
ffff0001ffb32070 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_queue_rq+0x20c/0xc48 drivers/block/nbd.c:1204

but task is already holding lock:
ffff0000e184e178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xb4/0xc48 drivers/block/nbd.c:1196

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #6 (&cmd->lock){+.+.}-{4:4}:
       __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:598
       __mutex_lock kernel/locking/mutex.c:760 [inline]
       mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812
       nbd_queue_rq+0xb4/0xc48 drivers/block/nbd.c:1196
       blk_mq_dispatch_rq_list+0x890/0x1548 block/blk-mq.c:2120
       __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
       blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
       __blk_mq_sched_dispatch_requests+0xa7c/0x10e4 block/blk-mq-sched.c:307
       blk_mq_sched_dispatch_requests+0xa4/0x154 block/blk-mq-sched.c:329
       blk_mq_run_hw_queue+0x2d0/0x4a4 block/blk-mq.c:2358
       blk_mq_dispatch_list+0xa00/0xaf8 block/blk-mq.c:-1
       blk_mq_flush_plug_list+0x3a4/0x488 block/blk-mq.c:2967
       __blk_flush_plug+0x330/0x408 block/blk-core.c:1220
       blk_finish_plug block/blk-core.c:1247 [inline]
       __submit_bio+0x3f4/0x4d8 block/blk-core.c:649
       __submit_bio_noacct_mq block/blk-core.c:722 [inline]
       submit_bio_noacct_nocheck+0x390/0xaac block/blk-core.c:751
       submit_bio_noacct+0xc94/0x177c block/blk-core.c:874
       submit_bio+0x3b4/0x550 block/blk-core.c:916
       submit_bh_wbc+0x3ec/0x4bc fs/buffer.c:2824
       submit_bh fs/buffer.c:2829 [inline]
       block_read_full_folio+0x734/0x824 fs/buffer.c:2461
       blkdev_read_folio+0x28/0x38 block/fops.c:491
       filemap_read_folio+0xec/0x2f8 mm/filemap.c:2413
       do_read_cache_folio+0x364/0x5bc mm/filemap.c:3957
       read_cache_folio+0x68/0x88 mm/filemap.c:3989
       read_mapping_folio include/linux/pagemap.h:991 [inline]
       read_part_sector+0xcc/0x6fc block/partitions/core.c:722
       adfspart_check_ICS+0xa0/0x83c block/partitions/acorn.c:360
       check_partition block/partitions/core.c:141 [inline]
       blk_add_partitions block/partitions/core.c:589 [inline]
       bdev_disk_changed+0x674/0x11fc block/partitions/core.c:693
       blkdev_get_whole+0x2b0/0x4a4 block/bdev.c:748
       bdev_open+0x3b0/0xc20 block/bdev.c:957
       blkdev_open+0x300/0x440 block/fops.c:691
       do_dentry_open+0x7a4/0x10bc fs/open.c:965
       vfs_open+0x44/0x2d4 fs/open.c:1095
       do_open fs/namei.c:3887 [inline]
       path_openat+0x2424/0x2c40 fs/namei.c:4046
       do_filp_open+0x18c/0x36c fs/namei.c:4073
       do_sys_openat2+0x11c/0x1b4 fs/open.c:1435
       do_sys_open fs/open.c:1450 [inline]
       __do_sys_openat fs/open.c:1466 [inline]
       __se_sys_openat fs/open.c:1461 [inline]
       __arm64_sys_openat+0x120/0x158 fs/open.c:1461
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:744
       el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

-> #5 (set->srcu){.+.+}-{0:0}:
       srcu_lock_sync+0x2c/0x38 include/linux/srcu.h:173
       __synchronize_srcu+0xa0/0x348 kernel/rcu/srcutree.c:1429
       synchronize_srcu+0x2cc/0x338 kernel/rcu/srcutree.c:-1
       blk_mq_wait_quiesce_done block/blk-mq.c:283 [inline]
       blk_mq_quiesce_queue+0x118/0x16c block/blk-mq.c:303
       elevator_switch+0x12c/0x410 block/elevator.c:588
       elevator_change+0x264/0x3cc block/elevator.c:690
       elevator_set_default+0x138/0x21c block/elevator.c:766
       blk_register_queue+0x2b4/0x338 block/blk-sysfs.c:904
       __add_disk+0x560/0xb90 block/genhd.c:528
       add_disk_fwnode+0xdc/0x438 block/genhd.c:597
       device_add_disk+0x38/0x4c block/genhd.c:627
       add_disk include/linux/blkdev.h:774 [inline]
       nbd_dev_add+0x560/0x820 drivers/block/nbd.c:1973
       nbd_init+0x15c/0x174 drivers/block/nbd.c:2680
       do_one_initcall+0x250/0x990 init/main.c:1269
       do_initcall_level+0x128/0x1c4 init/main.c:1331
       do_initcalls+0x70/0xd0 init/main.c:1347
       do_basic_setup+0x78/0x8c init/main.c:1366
       kernel_init_freeable+0x268/0x39c init/main.c:1579
       kernel_init+0x24/0x1dc init/main.c:1469
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844

-> #4 (&q->elevator_lock){+.+.}-{4:4}:
       __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:598
       __mutex_lock kernel/locking/mutex.c:760 [inline]
       mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812
       elevator_change+0x16c/0x3cc block/elevator.c:688
       elevator_set_none+0x48/0xac block/elevator.c:781
       blk_mq_elv_switch_none block/blk-mq.c:5023 [inline]
       __blk_mq_update_nr_hw_queues block/blk-mq.c:5066 [inline]
       blk_mq_update_nr_hw_queues+0x4c8/0x15f4 block/blk-mq.c:5124
       nbd_start_device+0x158/0xa48 drivers/block/nbd.c:1478
       nbd_genl_connect+0xf88/0x158c drivers/block/nbd.c:2228
       genl_family_rcv_msg_doit+0x1d8/0x2bc net/netlink/genetlink.c:1115
       genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
       genl_rcv_msg+0x450/0x624 net/netlink/genetlink.c:1210
       netlink_rcv_skb+0x220/0x3fc net/netlink/af_netlink.c:2552
       genl_rcv+0x38/0x50 net/netlink/genetlink.c:1219
       netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
       netlink_unicast+0x694/0x8c4 net/netlink/af_netlink.c:1346
       netlink_sendmsg+0x648/0x930 net/netlink/af_netlink.c:1896
       sock_sendmsg_nosec net/socket.c:714 [inline]
       __sock_sendmsg net/socket.c:729 [inline]
       ____sys_sendmsg+0x490/0x7b8 net/socket.c:2614
       ___sys_sendmsg+0x204/0x278 net/socket.c:2668
       __sys_sendmsg net/socket.c:2700 [inline]
       __do_sys_sendmsg net/socket.c:2705 [inline]
       __se_sys_sendmsg net/socket.c:2703 [inline]
       __arm64_sys_sendmsg+0x184/0x238 net/socket.c:2703
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:744
       el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

-> #3 (&q->q_usage_counter(io)#33){++++}-{0:0}:
       blk_alloc_queue+0x48c/0x54c block/blk-core.c:461
       blk_mq_alloc_queue block/blk-mq.c:4400 [inline]
       __blk_mq_alloc_disk+0x124/0x304 block/blk-mq.c:4447
       nbd_dev_add+0x398/0x820 drivers/block/nbd.c:1943
       nbd_init+0x15c/0x174 drivers/block/nbd.c:2680
       do_one_initcall+0x250/0x990 init/main.c:1269
       do_initcall_level+0x128/0x1c4 init/main.c:1331
       do_initcalls+0x70/0xd0 init/main.c:1347
       do_basic_setup+0x78/0x8c init/main.c:1366
       kernel_init_freeable+0x268/0x39c init/main.c:1579
       kernel_init+0x24/0x1dc init/main.c:1469
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844

-> #2 (fs_reclaim){+.+.}-{0:0}:
       __fs_reclaim_acquire mm/page_alloc.c:4234 [inline]
       fs_reclaim_acquire+0x8c/0x118 mm/page_alloc.c:4248
       might_alloc include/linux/sched/mm.h:318 [inline]
       slab_pre_alloc_hook mm/slub.c:4142 [inline]
       slab_alloc_node mm/slub.c:4220 [inline]
       __kmalloc_cache_noprof+0x58/0x3fc mm/slub.c:4402
       kmalloc_noprof include/linux/slab.h:905 [inline]
       kzalloc_noprof include/linux/slab.h:1039 [inline]
       virtio_transport_do_socket_init+0x60/0x2b8 net/vmw_vsock/virtio_transport_common.c:910
       vsock_assign_transport+0x514/0x65c net/vmw_vsock/af_vsock.c:537
       vsock_connect+0x4a8/0xb94 net/vmw_vsock/af_vsock.c:1583
       __sys_connect_file net/socket.c:2086 [inline]
       __sys_connect+0x2a0/0x3ac net/socket.c:2105
       __do_sys_connect net/socket.c:2111 [inline]
       __se_sys_connect net/socket.c:2108 [inline]
       __arm64_sys_connect+0x7c/0x94 net/socket.c:2108
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:744
       el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

-> #1 (sk_lock-AF_VSOCK){+.+.}-{0:0}:
       lock_sock_nested+0x58/0x118 net/core/sock.c:3711
       lock_sock include/net/sock.h:1669 [inline]
       vsock_shutdown+0x70/0x280 net/vmw_vsock/af_vsock.c:1103
       kernel_sock_shutdown+0x6c/0x80 net/socket.c:3701
       nbd_mark_nsock_dead+0x2a4/0x534 drivers/block/nbd.c:318
       recv_work+0x1cf8/0x2044 drivers/block/nbd.c:1018
       process_one_work+0x7e8/0x155c kernel/workqueue.c:3236
       process_scheduled_works kernel/workqueue.c:3319 [inline]
       worker_thread+0x958/0xed8 kernel/workqueue.c:3400
       kthread+0x5fc/0x75c kernel/kthread.c:463
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844

-> #0 (&nsock->tx_lock){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x1774/0x30a4 kernel/locking/lockdep.c:5237
       lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
       __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:598
       __mutex_lock kernel/locking/mutex.c:760 [inline]
       mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812
       nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
       nbd_queue_rq+0x20c/0xc48 drivers/block/nbd.c:1204
       blk_mq_dispatch_rq_list+0x890/0x1548 block/blk-mq.c:2120
       __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
       blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
       __blk_mq_sched_dispatch_requests+0xa7c/0x10e4 block/blk-mq-sched.c:307
       blk_mq_sched_dispatch_requests+0xa4/0x154 block/blk-mq-sched.c:329
       blk_mq_run_hw_queue+0x2d0/0x4a4 block/blk-mq.c:2358
       blk_mq_dispatch_list+0xa00/0xaf8 block/blk-mq.c:-1
       blk_mq_flush_plug_list+0x3a4/0x488 block/blk-mq.c:2967
       __blk_flush_plug+0x330/0x408 block/blk-core.c:1220
       blk_finish_plug block/blk-core.c:1247 [inline]
       __submit_bio+0x3f4/0x4d8 block/blk-core.c:649
       __submit_bio_noacct_mq block/blk-core.c:722 [inline]
       submit_bio_noacct_nocheck+0x390/0xaac block/blk-core.c:751
       submit_bio_noacct+0xc94/0x177c block/blk-core.c:874
       submit_bio+0x3b4/0x550 block/blk-core.c:916
       submit_bh_wbc+0x3ec/0x4bc fs/buffer.c:2824
       submit_bh fs/buffer.c:2829 [inline]
       block_read_full_folio+0x734/0x824 fs/buffer.c:2461
       blkdev_read_folio+0x28/0x38 block/fops.c:491
       filemap_read_folio+0xec/0x2f8 mm/filemap.c:2413
       do_read_cache_folio+0x364/0x5bc mm/filemap.c:3957
       read_cache_folio+0x68/0x88 mm/filemap.c:3989
       read_mapping_folio include/linux/pagemap.h:991 [inline]
       read_part_sector+0xcc/0x6fc block/partitions/core.c:722
       adfspart_check_ICS+0xa0/0x83c block/partitions/acorn.c:360
       check_partition block/partitions/core.c:141 [inline]
       blk_add_partitions block/partitions/core.c:589 [inline]
       bdev_disk_changed+0x674/0x11fc block/partitions/core.c:693
       blkdev_get_whole+0x2b0/0x4a4 block/bdev.c:748
       bdev_open+0x3b0/0xc20 block/bdev.c:957
       blkdev_open+0x300/0x440 block/fops.c:691
       do_dentry_open+0x7a4/0x10bc fs/open.c:965
       vfs_open+0x44/0x2d4 fs/open.c:1095
       do_open fs/namei.c:3887 [inline]
       path_openat+0x2424/0x2c40 fs/namei.c:4046
       do_filp_open+0x18c/0x36c fs/namei.c:4073
       do_sys_openat2+0x11c/0x1b4 fs/open.c:1435
       do_sys_open fs/open.c:1450 [inline]
       __do_sys_openat fs/open.c:1466 [inline]
       __se_sys_openat fs/open.c:1461 [inline]
       __arm64_sys_openat+0x120/0x158 fs/open.c:1461
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:744
       el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

other info that might help us debug this:

Chain exists of:
  &nsock->tx_lock --> set->srcu --> &cmd->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&cmd->lock);
                               lock(set->srcu);
                               lock(&cmd->lock);
  lock(&nsock->tx_lock);

 *** DEADLOCK ***

3 locks held by udevd/6531:
 #0: ffff0000cb97e358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xcc/0xc20 block/bdev.c:945
 #1: ffff0000cad37e90 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire+0x18/0x54 include/linux/srcu.h:160
 #2: ffff0000e184e178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xb4/0xc48 drivers/block/nbd.c:1196

stack backtrace:
CPU: 1 UID: 0 PID: 6531 Comm: udevd Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 print_circular_bug+0x324/0x32c kernel/locking/lockdep.c:2043
 check_noncircular+0x154/0x174 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x1774/0x30a4 kernel/locking/lockdep.c:5237
 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
 __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:598
 __mutex_lock kernel/locking/mutex.c:760 [inline]
 mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812
 nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
 nbd_queue_rq+0x20c/0xc48 drivers/block/nbd.c:1204
 blk_mq_dispatch_rq_list+0x890/0x1548 block/blk-mq.c:2120
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
 blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
 __blk_mq_sched_dispatch_requests+0xa7c/0x10e4 block/blk-mq-sched.c:307
 blk_mq_sched_dispatch_requests+0xa4/0x154 block/blk-mq-sched.c:329
 blk_mq_run_hw_queue+0x2d0/0x4a4 block/blk-mq.c:2358
 blk_mq_dispatch_list+0xa00/0xaf8 block/blk-mq.c:-1
 blk_mq_flush_plug_list+0x3a4/0x488 block/blk-mq.c:2967
 __blk_flush_plug+0x330/0x408 block/blk-core.c:1220
 blk_finish_plug block/blk-core.c:1247 [inline]
 __submit_bio+0x3f4/0x4d8 block/blk-core.c:649
 __submit_bio_noacct_mq block/blk-core.c:722 [inline]
 submit_bio_noacct_nocheck+0x390/0xaac block/blk-core.c:751
 submit_bio_noacct+0xc94/0x177c block/blk-core.c:874
 submit_bio+0x3b4/0x550 block/blk-core.c:916
 submit_bh_wbc+0x3ec/0x4bc fs/buffer.c:2824
 submit_bh fs/buffer.c:2829 [inline]
 block_read_full_folio+0x734/0x824 fs/buffer.c:2461
 blkdev_read_folio+0x28/0x38 block/fops.c:491
 filemap_read_folio+0xec/0x2f8 mm/filemap.c:2413
 do_read_cache_folio+0x364/0x5bc mm/filemap.c:3957
 read_cache_folio+0x68/0x88 mm/filemap.c:3989
 read_mapping_folio include/linux/pagemap.h:991 [inline]
 read_part_sector+0xcc/0x6fc block/partitions/core.c:722
 adfspart_check_ICS+0xa0/0x83c block/partitions/acorn.c:360
 check_partition block/partitions/core.c:141 [inline]
 blk_add_partitions block/partitions/core.c:589 [inline]
 bdev_disk_changed+0x674/0x11fc block/partitions/core.c:693
 blkdev_get_whole+0x2b0/0x4a4 block/bdev.c:748
 bdev_open+0x3b0/0xc20 block/bdev.c:957
 blkdev_open+0x300/0x440 block/fops.c:691
 do_dentry_open+0x7a4/0x10bc fs/open.c:965
 vfs_open+0x44/0x2d4 fs/open.c:1095
 do_open fs/namei.c:3887 [inline]
 path_openat+0x2424/0x2c40 fs/namei.c:4046
 do_filp_open+0x18c/0x36c fs/namei.c:4073
 do_sys_openat2+0x11c/0x1b4 fs/open.c:1435
 do_sys_open fs/open.c:1450 [inline]
 __do_sys_openat fs/open.c:1466 [inline]
 __se_sys_openat fs/open.c:1461 [inline]
 __arm64_sys_openat+0x120/0x158 fs/open.c:1461
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
block nbd0: Dead connection, failed to find a fallback
block nbd0: shutting down sockets
I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 0, async page read
I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 0, async page read
I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 0, async page read
I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 0, async page read
I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 0, async page read
I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 0, async page read
I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 0, async page read
I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 0, async page read
ldm_validate_partition_table(): Disk read failed.
I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 0, async page read
I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 0, async page read
Dev nbd0: unable to read RDB block 0
 nbd0: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd0: unable to read RDB block 0
 nbd0: unable to read partition table


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

  parent reply	other threads:[~2025-09-15  2:16 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-07-06 16:33 [syzbot] [nbd?] possible deadlock in nbd_queue_rq syzbot
2025-07-07  0:59 ` Hillf Danton
2025-07-07 17:39   ` Bart Van Assche
2025-07-08  0:18     ` Hillf Danton
2025-07-08  0:52       ` Tetsuo Handa
2025-07-08  1:24         ` Hillf Danton
2025-07-08  2:19           ` Tetsuo Handa
2025-07-08 16:23           ` Bart Van Assche
2025-09-15  2:16 ` syzbot [this message]
2025-09-16 18:18 ` syzbot

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=68c776fb.050a0220.2ff435.0387.GAE@google.com \
    --to=syzbot+3dbc6142c85cc77eaf04@syzkaller.appspotmail.com \
    --cc=axboe@kernel.dk \
    --cc=bvanassche@acm.org \
    --cc=hdanton@sina.com \
    --cc=josef@toxicpanda.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ming.lei@redhat.com \
    --cc=nbd@other.debian.org \
    --cc=penguin-kernel@i-love.sakura.ne.jp \
    --cc=syzkaller-bugs@googlegroups.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.