======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G L
------------------------------------------------------
syz.1.10180/8739 is trying to acquire lock:
ffffffff8e9aafc0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:317 [inline]
ffffffff8e9aafc0 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4489 [inline]
ffffffff8e9aafc0 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4843 [inline]
ffffffff8e9aafc0 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_node_noprof+0x53/0x6f0 mm/slub.c:4918
but task is already holding lock:
ffff888038354220 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1709 [inline]
ffff888038354220 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: inet_stream_connect+0x43/0xa0 net/ipv4/af_inet.c:755
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #7 (k-sk_lock-AF_INET){+.+.}-{0:0}:
lock_sock_fast include/net/sock.h:1741 [inline]
tcp_get_info+0x2a6/0x2870 net/ipv4/tcp.c:4284
do_tcp_getsockopt+0x954/0x2a90 net/ipv4/tcp.c:4575
tcp_getsockopt+0xe4/0x110 net/ipv4/tcp.c:4896
mptcp_getsockopt_first_sf_only net/mptcp/sockopt.c:949 [inline]
mptcp_getsockopt_sol_tcp net/mptcp/sockopt.c:1411 [inline]
mptcp_getsockopt+0xbdb/0xe50 net/mptcp/sockopt.c:1529
do_sock_getsockopt+0x259/0x3d0 net/socket.c:2383
__sys_getsockopt+0x148/0x260 net/socket.c:2412
__do_sys_getsockopt net/socket.c:2419 [inline]
__se_sys_getsockopt net/socket.c:2416 [inline]
__x64_sys_getsockopt+0xbd/0x160 net/socket.c:2416
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #6 (sk_lock-AF_INET){+.+.}-{0:0}:
lock_sock_nested+0x41/0xf0 net/core/sock.c:3780
lock_sock include/net/sock.h:1709 [inline]
inet_shutdown+0x67/0x410 net/ipv4/af_inet.c:919
nbd_mark_nsock_dead+0xae/0x5c0 drivers/block/nbd.c:318
sock_shutdown+0x16b/0x200 drivers/block/nbd.c:411
nbd_clear_sock drivers/block/nbd.c:1427 [inline]
nbd_config_put+0x1eb/0x750 drivers/block/nbd.c:1451
nbd_release+0xb7/0x190 drivers/block/nbd.c:1756
blkdev_put_whole+0xb0/0xf0 block/bdev.c:737
bdev_release+0x47f/0x6d0 block/bdev.c:1160
blkdev_release+0x15/0x20 block/fops.c:705
__fput+0x3ff/0xb40 fs/file_table.c:469
task_work_run+0x150/0x240 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0x100/0x4a0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x67c/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #5 (&nsock->tx_lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776
nbd_handle_cmd drivers/block/nbd.c:1143 [inline]
nbd_queue_rq+0x428/0x1080 drivers/block/nbd.c:1207
blk_mq_dispatch_rq_list+0x422/0x1e70 block/blk-mq.c:2148
__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+0xcea/0x1620 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x1c0 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x23c/0x670 block/blk-mq.c:2386
blk_mq_dispatch_list+0x51d/0x1360 block/blk-mq.c:2949
blk_mq_flush_plug_list block/blk-mq.c:2997 [inline]
blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2969
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1230
blk_finish_plug block/blk-core.c:1257 [inline]
__submit_bio+0x584/0x6c0 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x562/0xc10 block/blk-core.c:753
submit_bio_noacct+0xd17/0x2010 block/blk-core.c:884
blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline]
submit_bh_wbc+0x59c/0x770 fs/buffer.c:2821
submit_bh fs/buffer.c:2826 [inline]
block_read_full_folio+0x264/0x8e0 fs/buffer.c:2444
filemap_read_folio+0xfc/0x3b0 mm/filemap.c:2501
do_read_cache_folio+0x2d7/0x6b0 mm/filemap.c:4101
read_mapping_folio include/linux/pagemap.h:1028 [inline]
read_part_sector+0xd1/0x370 block/partitions/core.c:723
adfspart_check_ICS+0x93/0x910 block/partitions/acorn.c:360
check_partition block/partitions/core.c:142 [inline]
blk_add_partitions block/partitions/core.c:590 [inline]
bdev_disk_changed+0x7f8/0xc80 block/partitions/core.c:694
blkdev_get_whole+0x187/0x290 block/bdev.c:764
bdev_open+0x2c7/0xe40 block/bdev.c:973
blkdev_open+0x34e/0x4f0 block/fops.c:697
do_dentry_open+0x6d8/0x1660 fs/open.c:949
vfs_open+0x82/0x3f0 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x208c/0x31a0 fs/namei.c:4830
do_file_open+0x20e/0x430 fs/namei.c:4859
do_sys_openat2+0x10d/0x1e0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #4 (&cmd->lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776
nbd_queue_rq+0xba/0x1080 drivers/block/nbd.c:1199
blk_mq_dispatch_rq_list+0x422/0x1e70 block/blk-mq.c:2148
__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+0xcea/0x1620 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x1c0 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x23c/0x670 block/blk-mq.c:2386
blk_mq_dispatch_list+0x51d/0x1360 block/blk-mq.c:2949
blk_mq_flush_plug_list block/blk-mq.c:2997 [inline]
blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2969
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1230
blk_finish_plug block/blk-core.c:1257 [inline]
__submit_bio+0x584/0x6c0 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x562/0xc10 block/blk-core.c:753
submit_bio_noacct+0xd17/0x2010 block/blk-core.c:884
blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline]
submit_bh_wbc+0x59c/0x770 fs/buffer.c:2821
submit_bh fs/buffer.c:2826 [inline]
block_read_full_folio+0x264/0x8e0 fs/buffer.c:2444
filemap_read_folio+0xfc/0x3b0 mm/filemap.c:2501
do_read_cache_folio+0x2d7/0x6b0 mm/filemap.c:4101
read_mapping_folio include/linux/pagemap.h:1028 [inline]
read_part_sector+0xd1/0x370 block/partitions/core.c:723
adfspart_check_ICS+0x93/0x910 block/partitions/acorn.c:360
check_partition block/partitions/core.c:142 [inline]
blk_add_partitions block/partitions/core.c:590 [inline]
bdev_disk_changed+0x7f8/0xc80 block/partitions/core.c:694
blkdev_get_whole+0x187/0x290 block/bdev.c:764
bdev_open+0x2c7/0xe40 block/bdev.c:973
blkdev_open+0x34e/0x4f0 block/fops.c:697
do_dentry_open+0x6d8/0x1660 fs/open.c:949
vfs_open+0x82/0x3f0 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x208c/0x31a0 fs/namei.c:4830
do_file_open+0x20e/0x430 fs/namei.c:4859
do_sys_openat2+0x10d/0x1e0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #3 (set->srcu){.+.+}-{0:0}:
srcu_lock_sync include/linux/srcu.h:199 [inline]
__synchronize_srcu+0xa1/0x2a0 kernel/rcu/srcutree.c:1505
blk_mq_wait_quiesce_done block/blk-mq.c:284 [inline]
blk_mq_wait_quiesce_done block/blk-mq.c:281 [inline]
blk_mq_quiesce_queue block/blk-mq.c:304 [inline]
blk_mq_quiesce_queue+0x149/0x1c0 block/blk-mq.c:299
elevator_switch+0x17b/0x7e0 block/elevator.c:576
elevator_change+0x352/0x530 block/elevator.c:681
elevator_set_default+0x29e/0x360 block/elevator.c:754
blk_register_queue+0x412/0x590 block/blk-sysfs.c:946
__add_disk+0x73f/0xe40 block/genhd.c:528
add_disk_fwnode+0x118/0x5c0 block/genhd.c:597
add_disk include/linux/blkdev.h:785 [inline]
nbd_dev_add+0x77a/0xb10 drivers/block/nbd.c:1984
nbd_init+0x291/0x2b0 drivers/block/nbd.c:2692
do_one_initcall+0x11d/0x760 init/main.c:1382
do_initcall_level init/main.c:1444 [inline]
do_initcalls init/main.c:1460 [inline]
do_basic_setup init/main.c:1479 [inline]
kernel_init_freeable+0x6e5/0x7a0 init/main.c:1692
kernel_init+0x1f/0x1e0 init/main.c:1582
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
-> #2 (&q->elevator_lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776
elevator_change+0x1bc/0x530 block/elevator.c:679
elevator_set_none+0x92/0xf0 block/elevator.c:769
blk_mq_elv_switch_none block/blk-mq.c:5110 [inline]
__blk_mq_update_nr_hw_queues block/blk-mq.c:5155 [inline]
blk_mq_update_nr_hw_queues+0x4c1/0x15f0 block/blk-mq.c:5220
nbd_start_device+0x1a6/0xbd0 drivers/block/nbd.c:1489
nbd_start_device_ioctl drivers/block/nbd.c:1548 [inline]
__nbd_ioctl drivers/block/nbd.c:1623 [inline]
nbd_ioctl+0x4a6/0xd30 drivers/block/nbd.c:1663
blkdev_ioctl+0x5ad/0x6f0 block/ioctl.c:804
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (&q->q_usage_counter(io)#50){++++}-{0:0}:
blk_alloc_queue+0x610/0x790 block/blk-core.c:461
blk_mq_alloc_queue+0x174/0x290 block/blk-mq.c:4429
__blk_mq_alloc_disk+0x29/0x120 block/blk-mq.c:4476
nbd_dev_add+0x492/0xb10 drivers/block/nbd.c:1954
nbd_init+0x291/0x2b0 drivers/block/nbd.c:2692
do_one_initcall+0x11d/0x760 init/main.c:1382
do_initcall_level init/main.c:1444 [inline]
do_initcalls init/main.c:1460 [inline]
do_basic_setup init/main.c:1479 [inline]
kernel_init_freeable+0x6e5/0x7a0 init/main.c:1692
kernel_init+0x1f/0x1e0 init/main.c:1582
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
-> #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+0x14b8/0x2630 kernel/locking/lockdep.c:5237
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825
__fs_reclaim_acquire mm/page_alloc.c:4348 [inline]
fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4362
might_alloc include/linux/sched/mm.h:317 [inline]
slab_pre_alloc_hook mm/slub.c:4489 [inline]
slab_alloc_node mm/slub.c:4843 [inline]
kmem_cache_alloc_node_noprof+0x53/0x6f0 mm/slub.c:4918
__alloc_skb+0x140/0x710 net/core/skbuff.c:702
alloc_skb_fclone include/linux/skbuff.h:1433 [inline]
tcp_stream_alloc_skb+0x34/0x660 net/ipv4/tcp.c:945
tcp_connect+0xe8c/0x5630 net/ipv4/tcp_output.c:4361
tcp_v4_connect+0x1603/0x1b40 net/ipv4/tcp_ipv4.c:346
__inet_stream_connect+0x208/0xfa0 net/ipv4/af_inet.c:685
inet_stream_connect+0x57/0xa0 net/ipv4/af_inet.c:756
p9_fd_create_tcp+0x379/0x4d0 net/9p/trans_fd.c:917
p9_client_create+0x563/0xd40 net/9p/client.c:894
v9fs_session_init+0x40/0xce0 fs/9p/v9fs.c:442
v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97
vfs_get_tree+0x92/0x320 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
do_new_mount_fc fs/namespace.c:3763 [inline]
do_new_mount fs/namespace.c:3839 [inline]
path_mount+0x7d0/0x23d0 fs/namespace.c:4159
do_mount fs/namespace.c:4172 [inline]
__do_sys_mount fs/namespace.c:4361 [inline]
__se_sys_mount fs/namespace.c:4338 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:4338
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
fs_reclaim --> sk_lock-AF_INET --> k-sk_lock-AF_INET
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(k-sk_lock-AF_INET);
lock(sk_lock-AF_INET);
lock(k-sk_lock-AF_INET);
lock(fs_reclaim);
*** DEADLOCK ***
1 lock held by syz.1.10180/8739:
#0: ffff888038354220 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1709 [inline]
#0: ffff888038354220 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: inet_stream_connect+0x43/0xa0 net/ipv4/af_inet.c:755
stack backtrace:
CPU: 2 UID: 0 PID: 8739 Comm: syz.1.10180 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043
check_noncircular+0x146/0x160 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+0x14b8/0x2630 kernel/locking/lockdep.c:5237
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825
__fs_reclaim_acquire mm/page_alloc.c:4348 [inline]
fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4362
might_alloc include/linux/sched/mm.h:317 [inline]
slab_pre_alloc_hook mm/slub.c:4489 [inline]
slab_alloc_node mm/slub.c:4843 [inline]
kmem_cache_alloc_node_noprof+0x53/0x6f0 mm/slub.c:4918
__alloc_skb+0x140/0x710 net/core/skbuff.c:702
alloc_skb_fclone include/linux/skbuff.h:1433 [inline]
tcp_stream_alloc_skb+0x34/0x660 net/ipv4/tcp.c:945
tcp_connect+0xe8c/0x5630 net/ipv4/tcp_output.c:4361
tcp_v4_connect+0x1603/0x1b40 net/ipv4/tcp_ipv4.c:346
__inet_stream_connect+0x208/0xfa0 net/ipv4/af_inet.c:685
inet_stream_connect+0x57/0xa0 net/ipv4/af_inet.c:756
p9_fd_create_tcp+0x379/0x4d0 net/9p/trans_fd.c:917
p9_client_create+0x563/0xd40 net/9p/client.c:894
v9fs_session_init+0x40/0xce0 fs/9p/v9fs.c:442
v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97
vfs_get_tree+0x92/0x320 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
do_new_mount_fc fs/namespace.c:3763 [inline]
do_new_mount fs/namespace.c:3839 [inline]
path_mount+0x7d0/0x23d0 fs/namespace.c:4159
do_mount fs/namespace.c:4172 [inline]
__do_sys_mount fs/namespace.c:4361 [inline]
__se_sys_mount fs/namespace.c:4338 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:4338
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f614c59c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f614d4ce028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f614c816090 RCX: 00007f614c59c799
RDX: 0000200000000040 RSI: 0000200000000680 RDI: 0000200000000640
RBP: 00007f614c632c99 R08: 00002000000000c0 R09: 0000000000000000
R10: 0000000000008010 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f614c816128 R14: 00007f614c816090 R15: 00007ffef49712c8
</TASK>
9pnet_fd: p9_fd_create_tcp (8739): problem connecting socket to 127.0.0.1