======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.2.3749/14478 is trying to acquire lock:
ffffffff8ea852e0 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc_cache_noprof+0x40/0x660

but task is already holding lock:
ffff88811fb3c360 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x21/0x50

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_nested+0x41/0x100
       __inet_bind+0x3b0/0xaa0
       mptcp_bind+0x128/0x1d0
       __sys_bind+0x2e3/0x410
       __x64_sys_bind+0x7a/0x90
       do_syscall_64+0x174/0x580
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #6 (sk_lock-AF_INET){+.+.}-{0:0}:
       lock_sock_nested+0x41/0x100
       inet_shutdown+0x6a/0x390
       nbd_mark_nsock_dead+0x2cb/0x550
       recv_work+0x1cef/0x1e10
       process_scheduled_works+0xa8e/0x14e0
       worker_thread+0xa47/0xfb0
       kthread+0x388/0x470
       ret_from_fork+0x514/0xb70
       ret_from_fork_asm+0x1a/0x30

-> #5 (&nsock->tx_lock){+.+.}-{4:4}:
       __mutex_lock+0x19d/0x1590
       nbd_queue_rq+0x373/0x1150
       blk_mq_dispatch_rq_list+0x499/0x1990
       __blk_mq_sched_dispatch_requests+0xd36/0x1580
       blk_mq_sched_dispatch_requests+0xd7/0x190
       blk_mq_run_hw_queue+0x348/0x4f0
       blk_mq_dispatch_list+0xd11/0xe10
       blk_mq_flush_plug_list+0x45f/0x540
       __blk_flush_plug+0x3ed/0x4d0
       __submit_bio+0x465/0x560
       submit_bio_noacct_nocheck+0x2f4/0xa40
       block_read_full_folio+0x581/0x810
       filemap_read_folio+0x12c/0x3a0
       do_read_cache_folio+0x354/0x590
       read_part_sector+0xb6/0x2b0
       adfspart_check_ICS+0xb1/0x960
       bdev_disk_changed+0x82b/0x1780
       blkdev_get_whole+0x372/0x510
       bdev_open+0x324/0xd70
       blkdev_open+0x461/0x600
       do_dentry_open+0x816/0x1380
       vfs_open+0x3b/0x340
       path_openat+0x2e44/0x3830
       do_file_open+0x23e/0x4a0
       do_sys_openat2+0x115/0x200
       __x64_sys_openat+0x138/0x170
       do_syscall_64+0x174/0x580
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #4 (&cmd->lock){+.+.}-{4:4}:
       __mutex_lock+0x19d/0x1590
       nbd_queue_rq+0xc1/0x1150
       blk_mq_dispatch_rq_list+0x499/0x1990
       __blk_mq_sched_dispatch_requests+0xd36/0x1580
       blk_mq_sched_dispatch_requests+0xd7/0x190
       blk_mq_run_hw_queue+0x348/0x4f0
       blk_mq_dispatch_list+0xd11/0xe10
       blk_mq_flush_plug_list+0x45f/0x540
       __blk_flush_plug+0x3ed/0x4d0
       __submit_bio+0x465/0x560
       submit_bio_noacct_nocheck+0x2f4/0xa40
       block_read_full_folio+0x581/0x810
       filemap_read_folio+0x12c/0x3a0
       do_read_cache_folio+0x354/0x590
       read_part_sector+0xb6/0x2b0
       adfspart_check_ICS+0xb1/0x960
       bdev_disk_changed+0x82b/0x1780
       blkdev_get_whole+0x372/0x510
       bdev_open+0x324/0xd70
       blkdev_open+0x461/0x600
       do_dentry_open+0x816/0x1380
       vfs_open+0x3b/0x340
       path_openat+0x2e44/0x3830
       do_file_open+0x23e/0x4a0
       do_sys_openat2+0x115/0x200
       __x64_sys_openat+0x138/0x170
       do_syscall_64+0x174/0x580
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #3 (set->srcu){.+.+}-{0:0}:
       __synchronize_srcu+0xc9/0x2f0
       elevator_switch+0x1e8/0x7b0
       elevator_change+0x2fa/0x480
       elevator_set_default+0x375/0x440
       blk_register_queue+0x3f3/0x4e0
       __add_disk+0x6cb/0xe30
       add_disk_fwnode+0xfb/0x4b0
       nbd_dev_add+0x733/0xb60
       nbd_init+0x15f/0x1e0
       do_one_initcall+0x250/0x870
       do_initcall_level+0x10a/0x1a0
       do_initcalls+0x59/0xa0
       kernel_init_freeable+0x29d/0x3e0
       kernel_init+0x1d/0x1d0
       ret_from_fork+0x514/0xb70
       ret_from_fork_asm+0x1a/0x30

-> #2 (&q->elevator_lock){+.+.}-{4:4}:
       __mutex_lock+0x19d/0x1590
       elevator_change+0x1af/0x480
       elevator_set_none+0xb5/0x140
       blk_mq_update_nr_hw_queues+0x5ef/0x19f0
       nbd_start_device+0x189/0xb30
       nbd_genl_connect+0x1597/0x1c10
       genl_family_rcv_msg_doit+0x233/0x340
       genl_rcv_msg+0x614/0x7a0
       netlink_rcv_skb+0x226/0x4a0
       genl_rcv+0x28/0x40
       netlink_unicast+0x7bb/0x940
       netlink_sendmsg+0x813/0xb40
       ____sys_sendmsg+0x9b9/0xa20
       ___sys_sendmsg+0x2a5/0x360
       __x64_sys_sendmsg+0x1bd/0x2a0
       do_syscall_64+0x174/0x580
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&q->q_usage_counter(io)#51){++++}-{0:0}:
       blk_alloc_queue+0x544/0x690
       __blk_mq_alloc_disk+0x194/0x390
       nbd_dev_add+0x494/0xb60
       nbd_init+0x15f/0x1e0
       do_one_initcall+0x250/0x870
       do_initcall_level+0x10a/0x1a0
       do_initcalls+0x59/0xa0
       kernel_init_freeable+0x29d/0x3e0
       kernel_init+0x1d/0x1d0
       ret_from_fork+0x514/0xb70
       ret_from_fork_asm+0x1a/0x30

-> #0 (fs_reclaim){+.+.}-{0:0}:
       __lock_acquire+0x1520/0x2cd0
       lock_acquire+0x106/0x350
       fs_reclaim_acquire+0x71/0x100
       __kmalloc_cache_noprof+0x40/0x660
       tcp_sendmsg_fastopen+0x1e7/0x5f0
       tcp_sendmsg_locked+0x4cdc/0x55c0
       tcp_sendmsg+0x2f/0x50
       smc_sendmsg+0x250/0x4d0
       ____sys_sendmsg+0x9b9/0xa20
       ___sys_sendmsg+0x2a5/0x360
       __x64_sys_sendmsg+0x1bd/0x2a0
       do_syscall_64+0x174/0x580
       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 ***

2 locks held by syz.2.3749/14478:
 #0: ffff888113b727e0 (sk_lock-AF_SMC){+.+.}-{0:0}, at: smc_sendmsg+0x52/0x4d0
 #1: ffff88811fb3c360 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x21/0x50

stack backtrace:
CPU: 0 UID: 0 PID: 14478 Comm: syz.2.3749 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_circular_bug+0x2e1/0x300
 check_noncircular+0x12e/0x150
 __lock_acquire+0x1520/0x2cd0
 lock_acquire+0x106/0x350
 fs_reclaim_acquire+0x71/0x100
 __kmalloc_cache_noprof+0x40/0x660
 tcp_sendmsg_fastopen+0x1e7/0x5f0
 tcp_sendmsg_locked+0x4cdc/0x55c0
 tcp_sendmsg+0x2f/0x50
 smc_sendmsg+0x250/0x4d0
 ____sys_sendmsg+0x9b9/0xa20
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1bd/0x2a0
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb943d9ce59
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:00007fb944c88028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb944015fa0 RCX: 00007fb943d9ce59
RDX: 0000000020000080 RSI: 0000200000000080 RDI: 0000000000000004
RBP: 00007fb943e32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb944016038 R14: 00007fb944015fa0 R15: 00007fffdd19e948
 </TASK>
