======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc6-syzkaller-00244-g31d7109a19f6 #0 Not tainted
------------------------------------------------------
syz.8.1877/14885 is trying to acquire lock:
ffff888025925290 (set->srcu){.+.+}-{0:0}, at: srcu_lock_sync include/linux/srcu.h:176 [inline]
ffff888025925290 (set->srcu){.+.+}-{0:0}, at: __synchronize_srcu+0x9d/0x400 kernel/rcu/srcutree.c:1418
but task is already holding lock:
ffff888144bae1b8 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_elv_switch_none block/blk-mq.c:4937 [inline]
ffff888144bae1b8 (&q->sysfs_lock){+.+.}-{4:4}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5018 [inline]
ffff888144bae1b8 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0x388/0x1a30 block/blk-mq.c:5070
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #7 (&q->sysfs_lock){+.+.}-{4:4}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730
blk_mq_elv_switch_none block/blk-mq.c:4937 [inline]
__blk_mq_update_nr_hw_queues block/blk-mq.c:5018 [inline]
blk_mq_update_nr_hw_queues+0x388/0x1a30 block/blk-mq.c:5070
nbd_start_device+0x163/0xab0 drivers/block/nbd.c:1476
nbd_start_device_ioctl drivers/block/nbd.c:1527 [inline]
__nbd_ioctl drivers/block/nbd.c:1602 [inline]
nbd_ioctl+0x5dc/0xf40 drivers/block/nbd.c:1642
blkdev_ioctl+0x5d2/0x6f0 block/ioctl.c:693
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892
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
-> #6 (&q->q_usage_counter(io)#57){++++}-{0:0}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
bio_queue_enter block/blk.h:78 [inline]
blk_mq_submit_bio+0x14e1/0x25d0 block/blk-mq.c:3091
__submit_bio+0x2cf/0x6a0 block/blk-core.c:628
__submit_bio_noacct_mq block/blk-core.c:715 [inline]
submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:744
submit_bh fs/buffer.c:2819 [inline]
block_read_full_folio+0x9b3/0xae0 fs/buffer.c:2446
filemap_read_folio+0x14a/0x3b0 mm/filemap.c:2389
filemap_update_page mm/filemap.c:2473 [inline]
filemap_get_pages+0x1791/0x1fb0 mm/filemap.c:2601
filemap_read+0x464/0x1260 mm/filemap.c:2690
blkdev_read_iter+0x31f/0x460 block/fops.c:796
new_sync_read fs/read_write.c:484 [inline]
vfs_read+0x977/0xb40 fs/read_write.c:565
ksys_read+0x18f/0x2b0 fs/read_write.c:708
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
-> #5 (mapping.invalidate_lock#2){.+.+}-{4:4}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524
filemap_invalidate_lock_shared include/linux/fs.h:932 [inline]
filemap_fault+0x615/0x1490 mm/filemap.c:3379
__do_fault+0x137/0x390 mm/memory.c:4989
do_read_fault mm/memory.c:5409 [inline]
do_fault mm/memory.c:5543 [inline]
do_pte_missing mm/memory.c:4059 [inline]
handle_pte_fault mm/memory.c:5888 [inline]
__handle_mm_fault+0x40c6/0x6ef0 mm/memory.c:6031
handle_mm_fault+0x3e5/0x8d0 mm/memory.c:6200
faultin_page mm/gup.c:1196 [inline]
__get_user_pages+0x1a92/0x4140 mm/gup.c:1491
populate_vma_page_range+0x264/0x330 mm/gup.c:1929
__mm_populate+0x27a/0x460 mm/gup.c:2032
mm_populate include/linux/mm.h:3386 [inline]
vm_mmap_pgoff+0x38e/0x530 mm/util.c:583
ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:607
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
-> #4 (&mm->mmap_lock){++++}-{4:4}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
__might_fault+0xc6/0x120 mm/memory.c:6839
_copy_from_iter+0x100/0x1c40 lib/iov_iter.c:259
copy_from_iter include/linux/uio.h:228 [inline]
copy_from_iter_full include/linux/uio.h:245 [inline]
skb_do_copy_data_nocache include/net/sock.h:2197 [inline]
skb_copy_to_page_nocache include/net/sock.h:2223 [inline]
tcp_sendmsg_locked+0x213d/0x5330 net/ipv4/tcp.c:1222
tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1358
sock_sendmsg_nosec net/socket.c:718 [inline]
__sock_sendmsg+0x1a6/0x270 net/socket.c:733
sock_write_iter+0x2d7/0x3f0 net/socket.c:1137
new_sync_write fs/read_write.c:586 [inline]
vfs_write+0xad1/0xd10 fs/read_write.c:679
ksys_write+0x18f/0x2b0 fs/read_write.c:731
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
-> #3 (sk_lock-AF_INET){+.+.}-{0:0}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
lock_sock_nested+0x48/0x100 net/core/sock.c:3662
lock_sock include/net/sock.h:1624 [inline]
inet_shutdown+0x6d/0x390 net/ipv4/af_inet.c:905
nbd_mark_nsock_dead+0x2e3/0x560 drivers/block/nbd.c:318
recv_work+0x225a/0x25c0 drivers/block/nbd.c:1018
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3319
worker_thread+0x870/0xd30 kernel/workqueue.c:3400
kthread+0x7ab/0x920 kernel/kthread.c:464
ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
-> #2 (&nsock->tx_lock){+.+.}-{4:4}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730
nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
nbd_queue_rq+0x262/0xef0 drivers/block/nbd.c:1204
blk_mq_dispatch_rq_list+0xad5/0x19d0 block/blk-mq.c:2120
__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+0xd6/0x190 block/blk-mq-sched.c:331
blk_mq_run_hw_queue+0x354/0x500 block/blk-mq.c:2354
blk_mq_flush_plug_list+0x118e/0x1870 block/blk-mq.c:2917
__blk_flush_plug+0x420/0x500 block/blk-core.c:1213
blk_finish_plug block/blk-core.c:1240 [inline]
__submit_bio+0x54a/0x6a0 block/blk-core.c:642
__submit_bio_noacct_mq block/blk-core.c:715 [inline]
submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:744
submit_bh fs/buffer.c:2819 [inline]
block_read_full_folio+0x9b3/0xae0 fs/buffer.c:2446
filemap_read_folio+0x14a/0x3b0 mm/filemap.c:2389
do_read_cache_folio+0x373/0x5b0 mm/filemap.c:3873
read_mapping_folio include/linux/pagemap.h:1023 [inline]
read_part_sector+0xb3/0x260 block/partitions/core.c:722
adfspart_check_ICS+0xcb/0xa20 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+0x781/0x14d0 block/partitions/core.c:693
blkdev_get_whole+0x2d2/0x450 block/bdev.c:706
bdev_open+0x2d4/0xc50 block/bdev.c:915
blkdev_open+0x38e/0x4e0 block/fops.c:652
do_dentry_open+0xdee/0x1960 fs/open.c:956
vfs_open+0x3b/0x370 fs/open.c:1086
do_open fs/namei.c:3830 [inline]
path_openat+0x2c81/0x3590 fs/namei.c:3989
do_filp_open+0x27f/0x4e0 fs/namei.c:4016
do_sys_openat2+0x13e/0x1d0 fs/open.c:1428
do_sys_open fs/open.c:1443 [inline]
__do_sys_openat fs/open.c:1459 [inline]
__se_sys_openat fs/open.c:1454 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1454
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
-> #1 (&cmd->lock){+.+.}-{4:4}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730
nbd_queue_rq+0xcf/0xef0 drivers/block/nbd.c:1196
blk_mq_dispatch_rq_list+0xad5/0x19d0 block/blk-mq.c:2120
__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+0xd6/0x190 block/blk-mq-sched.c:331
blk_mq_run_hw_queue+0x354/0x500 block/blk-mq.c:2354
blk_mq_flush_plug_list+0x118e/0x1870 block/blk-mq.c:2917
__blk_flush_plug+0x420/0x500 block/blk-core.c:1213
blk_finish_plug block/blk-core.c:1240 [inline]
__submit_bio+0x54a/0x6a0 block/blk-core.c:642
__submit_bio_noacct_mq block/blk-core.c:715 [inline]
submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:744
submit_bh fs/buffer.c:2819 [inline]
block_read_full_folio+0x9b3/0xae0 fs/buffer.c:2446
filemap_read_folio+0x14a/0x3b0 mm/filemap.c:2389
do_read_cache_folio+0x373/0x5b0 mm/filemap.c:3873
read_mapping_folio include/linux/pagemap.h:1023 [inline]
read_part_sector+0xb3/0x260 block/partitions/core.c:722
adfspart_check_ICS+0xcb/0xa20 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+0x781/0x14d0 block/partitions/core.c:693
blkdev_get_whole+0x2d2/0x450 block/bdev.c:706
bdev_open+0x2d4/0xc50 block/bdev.c:915
blkdev_open+0x38e/0x4e0 block/fops.c:652
do_dentry_open+0xdee/0x1960 fs/open.c:956
vfs_open+0x3b/0x370 fs/open.c:1086
do_open fs/namei.c:3830 [inline]
path_openat+0x2c81/0x3590 fs/namei.c:3989
do_filp_open+0x27f/0x4e0 fs/namei.c:4016
do_sys_openat2+0x13e/0x1d0 fs/open.c:1428
do_sys_open fs/open.c:1443 [inline]
__do_sys_openat fs/open.c:1459 [inline]
__se_sys_openat fs/open.c:1454 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1454
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
-> #0 (set->srcu){.+.+}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3163 [inline]
check_prevs_add kernel/locking/lockdep.c:3282 [inline]
validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
__lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
lock_sync+0x18b/0x310 kernel/locking/lockdep.c:5899
srcu_lock_sync include/linux/srcu.h:176 [inline]
__synchronize_srcu+0xb1/0x400 kernel/rcu/srcutree.c:1418
elevator_disable+0xd4/0x4e0 block/elevator.c:661
blk_mq_elv_switch_none block/blk-mq.c:4951 [inline]
__blk_mq_update_nr_hw_queues block/blk-mq.c:5018 [inline]
blk_mq_update_nr_hw_queues+0x5d3/0x1a30 block/blk-mq.c:5070
nbd_start_device+0x163/0xab0 drivers/block/nbd.c:1476
nbd_start_device_ioctl drivers/block/nbd.c:1527 [inline]
__nbd_ioctl drivers/block/nbd.c:1602 [inline]
nbd_ioctl+0x5dc/0xf40 drivers/block/nbd.c:1642
blkdev_ioctl+0x5d2/0x6f0 block/ioctl.c:693
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892
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
other info that might help us debug this:
Chain exists of:
set->srcu --> &q->q_usage_counter(io)#57 --> &q->sysfs_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&q->sysfs_lock);
lock(&q->q_usage_counter(io)#57);
lock(&q->sysfs_lock);
sync(set->srcu);
*** DEADLOCK ***
5 locks held by syz.8.1877/14885:
#0: ffff88802586f198 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x13c/0xf40 drivers/block/nbd.c:1635
#1: ffff88802586f0d8 (&set->tag_list_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0xa0/0x1a30 block/blk-mq.c:5069
#2: ffff888144badc88 (&q->q_usage_counter(io)#57){++++}-{0:0}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5010 [inline]
#2: ffff888144badc88 (&q->q_usage_counter(io)#57){++++}-{0:0}, at: blk_mq_update_nr_hw_queues+0x2c3/0x1a30 block/blk-mq.c:5070
#3: ffff888144badcc0 (&q->q_usage_counter(queue)#41){+.+.}-{0:0}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5010 [inline]
#3: ffff888144badcc0 (&q->q_usage_counter(queue)#41){+.+.}-{0:0}, at: blk_mq_update_nr_hw_queues+0x2c3/0x1a30 block/blk-mq.c:5070
#4: ffff888144bae1b8 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_elv_switch_none block/blk-mq.c:4937 [inline]
#4: ffff888144bae1b8 (&q->sysfs_lock){+.+.}-{4:4}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5018 [inline]
#4: ffff888144bae1b8 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0x388/0x1a30 block/blk-mq.c:5070
stack backtrace:
CPU: 1 UID: 0 PID: 14885 Comm: syz.8.1877 Not tainted 6.14.0-rc6-syzkaller-00244-g31d7109a19f6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076
check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208
check_prev_add kernel/locking/lockdep.c:3163 [inline]
check_prevs_add kernel/locking/lockdep.c:3282 [inline]
validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
__lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
lock_sync+0x18b/0x310 kernel/locking/lockdep.c:5899
srcu_lock_sync include/linux/srcu.h:176 [inline]
__synchronize_srcu+0xb1/0x400 kernel/rcu/srcutree.c:1418
elevator_disable+0xd4/0x4e0 block/elevator.c:661
blk_mq_elv_switch_none block/blk-mq.c:4951 [inline]
__blk_mq_update_nr_hw_queues block/blk-mq.c:5018 [inline]
blk_mq_update_nr_hw_queues+0x5d3/0x1a30 block/blk-mq.c:5070
nbd_start_device+0x163/0xab0 drivers/block/nbd.c:1476
nbd_start_device_ioctl drivers/block/nbd.c:1527 [inline]
__nbd_ioctl drivers/block/nbd.c:1602 [inline]
nbd_ioctl+0x5dc/0xf40 drivers/block/nbd.c:1642
blkdev_ioctl+0x5d2/0x6f0 block/ioctl.c:693
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892
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: 0033:0x7ff557b8d169
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:00007ff5589f1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff557da5fa0 RCX: 00007ff557b8d169
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007ff557c0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff557da5fa0 R15: 00007fffe325f2f8
</TASK>