======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.329/8842 is trying to acquire lock:
ffff80008fac3da0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:318 [inline]
ffff80008fac3da0 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4142 [inline]
ffff80008fac3da0 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4220 [inline]
ffff80008fac3da0 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_node_noprof+0x60/0x3f4 mm/slub.c:4292
but task is already holding lock:
ffff0000f36a13d8 (sk_lock-AF_VSOCK){+.+.}-{0:0}, at: __vsock_release+0x38/0x3b8 net/vmw_vsock/af_vsock.c:860
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #6 (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
-> #5 (&nsock->tx_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_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:492
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+0x364/0x4e8 block/fops.c:694
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
-> #4 (&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]
__bread_slow fs/buffer.c:1272 [inline]
__bread_gfp+0x134/0x34c fs/buffer.c:1518
sb_bread include/linux/buffer_head.h:346 [inline]
minix_fill_super+0x124/0x1690 fs/minix/inode.c:196
get_tree_bdev_flags+0x360/0x414 fs/super.c:1692
get_tree_bdev+0x2c/0x3c fs/super.c:1715
minix_get_tree+0x28/0x38 fs/minix/inode.c:377
vfs_get_tree+0x90/0x28c fs/super.c:1815
do_new_mount+0x278/0x7f4 fs/namespace.c:3808
path_mount+0x5b4/0xde0 fs/namespace.c:4123
do_mount fs/namespace.c:4136 [inline]
__do_sys_mount fs/namespace.c:4347 [inline]
__se_sys_mount fs/namespace.c:4324 [inline]
__arm64_sys_mount+0x3e8/0x468 fs/namespace.c:4324
__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 (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
-> #2 (&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
-> #1 (&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
-> #0 (fs_reclaim){+.+.}-{0:0}:
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
__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]
kmem_cache_alloc_node_noprof+0x60/0x3f4 mm/slub.c:4292
__alloc_skb+0x144/0x2ec net/core/skbuff.c:659
alloc_skb include/linux/skbuff.h:1336 [inline]
alloc_skb_with_frags+0xb8/0x678 net/core/skbuff.c:6665
__virtio_vsock_alloc_skb_with_frags include/linux/virtio_vsock.h:68 [inline]
virtio_vsock_alloc_linear_skb include/linux/virtio_vsock.h:81 [inline]
virtio_vsock_alloc_skb include/linux/virtio_vsock.h:87 [inline]
virtio_transport_alloc_skb+0xd4/0xf3c net/vmw_vsock/virtio_transport_common.c:267
virtio_transport_send_pkt_info+0x3fc/0xc60 net/vmw_vsock/virtio_transport_common.c:390
virtio_transport_shutdown net/vmw_vsock/virtio_transport_common.c:1087 [inline]
virtio_transport_close net/vmw_vsock/virtio_transport_common.c:1268 [inline]
virtio_transport_release+0x1e0/0x668 net/vmw_vsock/virtio_transport_common.c:1291
__vsock_release+0xa4/0x3b8 net/vmw_vsock/af_vsock.c:870
vsock_release+0x98/0xfc net/vmw_vsock/af_vsock.c:982
__sock_release net/socket.c:649 [inline]
sock_close+0xa0/0x1e4 net/socket.c:1439
__fput+0x340/0x75c fs/file_table.c:468
____fput+0x20/0x58 fs/file_table.c:496
task_work_run+0x1dc/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xfc/0x168 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline]
el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:745
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:
fs_reclaim --> &nsock->tx_lock --> sk_lock-AF_VSOCK
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sk_lock-AF_VSOCK);
lock(&nsock->tx_lock);
lock(sk_lock-AF_VSOCK);
lock(fs_reclaim);
*** DEADLOCK ***
2 locks held by syz.3.329/8842:
#0: ffff0000de132608 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline]
#0: ffff0000de132608 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:648 [inline]
#0: ffff0000de132608 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x7c/0x1e4 net/socket.c:1439
#1: ffff0000f36a13d8 (sk_lock-AF_VSOCK){+.+.}-{0:0}, at: __vsock_release+0x38/0x3b8 net/vmw_vsock/af_vsock.c:860
stack backtrace:
CPU: 0 UID: 0 PID: 8842 Comm: syz.3.329 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
__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]
kmem_cache_alloc_node_noprof+0x60/0x3f4 mm/slub.c:4292
__alloc_skb+0x144/0x2ec net/core/skbuff.c:659
alloc_skb include/linux/skbuff.h:1336 [inline]
alloc_skb_with_frags+0xb8/0x678 net/core/skbuff.c:6665
__virtio_vsock_alloc_skb_with_frags include/linux/virtio_vsock.h:68 [inline]
virtio_vsock_alloc_linear_skb include/linux/virtio_vsock.h:81 [inline]
virtio_vsock_alloc_skb include/linux/virtio_vsock.h:87 [inline]
virtio_transport_alloc_skb+0xd4/0xf3c net/vmw_vsock/virtio_transport_common.c:267
virtio_transport_send_pkt_info+0x3fc/0xc60 net/vmw_vsock/virtio_transport_common.c:390
virtio_transport_shutdown net/vmw_vsock/virtio_transport_common.c:1087 [inline]
virtio_transport_close net/vmw_vsock/virtio_transport_common.c:1268 [inline]
virtio_transport_release+0x1e0/0x668 net/vmw_vsock/virtio_transport_common.c:1291
__vsock_release+0xa4/0x3b8 net/vmw_vsock/af_vsock.c:870
vsock_release+0x98/0xfc net/vmw_vsock/af_vsock.c:982
__sock_release net/socket.c:649 [inline]
sock_close+0xa0/0x1e4 net/socket.c:1439
__fput+0x340/0x75c fs/file_table.c:468
____fput+0x20/0x58 fs/file_table.c:496
task_work_run+0x1dc/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xfc/0x168 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline]
el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:745
el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596