======================================================
WARNING: possible circular locking dependency detected
6.8.0-rc5-syzkaller-00381-g70ff1fe626a1 #0 Not tainted
------------------------------------------------------
syz-executor.1/24282 is trying to acquire lock:
ffff8880340e19b0 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]
ffff8880340e19b0 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_diag_get_aux+0x73a/0x830 net/ipv4/tcp_diag.c:137

but task is already holding lock:
ffffc90001351ad0 (&h->lhash2[i].lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffc90001351ad0 (&h->lhash2[i].lock){+.+.}-{2:2}, at: inet_diag_dump_icsk+0x39f/0x1f80 net/ipv4/inet_diag.c:1038

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&h->lhash2[i].lock){+.+.}-{2:2}:
       lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:351 [inline]
       __inet_hash+0x335/0xbe0 net/ipv4/inet_hashtables.c:743
       inet_csk_listen_start+0x23c/0x320 net/ipv4/inet_connection_sock.c:1261
       __inet_listen_sk+0x2a2/0x770 net/ipv4/af_inet.c:217
       mptcp_pm_nl_create_listen_socket net/mptcp/pm_netlink.c:1062 [inline]
       mptcp_pm_nl_add_addr_doit+0x103a/0x1360 net/mptcp/pm_netlink.c:1339
       genl_family_rcv_msg_doit net/netlink/genetlink.c:1113 [inline]
       genl_family_rcv_msg net/netlink/genetlink.c:1193 [inline]
       genl_rcv_msg+0xad8/0xe50 net/netlink/genetlink.c:1208
       netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2543
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1217
       netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
       netlink_unicast+0x7ec/0x980 net/netlink/af_netlink.c:1367
       netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908
       sock_sendmsg_nosec net/socket.c:730 [inline]
       __sock_sendmsg+0x223/0x270 net/socket.c:745
       ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584
       ___sys_sendmsg net/socket.c:2638 [inline]
       __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667
       do_syscall_64+0xfb/0x240
       entry_SYSCALL_64_after_hwframe+0x6f/0x77

-> #0 (k-sk_lock-AF_INET){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
       lock_sock_fast include/net/sock.h:1723 [inline]
       subflow_get_info+0x166/0xd20 net/mptcp/diag.c:28
       tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]
       tcp_diag_get_aux+0x73a/0x830 net/ipv4/tcp_diag.c:137
       inet_sk_diag_fill+0x10ef/0x1e00 net/ipv4/inet_diag.c:345
       inet_diag_dump_icsk+0x55b/0x1f80 net/ipv4/inet_diag.c:1061
       __inet_diag_dump+0x213/0x3a0 net/ipv4/inet_diag.c:1263
       inet_diag_dump_compat+0x1c1/0x2d0 net/ipv4/inet_diag.c:1371
       netlink_dump+0x59d/0xc80 net/netlink/af_netlink.c:2264
       __netlink_dump_start+0x5df/0x790 net/netlink/af_netlink.c:2370
       netlink_dump_start include/linux/netlink.h:338 [inline]
       inet_diag_rcv_msg_compat+0x209/0x4c0 net/ipv4/inet_diag.c:1405
       sock_diag_rcv_msg+0xe9/0x410
       netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2543
       sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:280
       netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
       netlink_unicast+0x7ec/0x980 net/netlink/af_netlink.c:1367
       netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908
       sock_sendmsg_nosec net/socket.c:730 [inline]
       __sock_sendmsg+0x223/0x270 net/socket.c:745
       sock_sendmsg+0x134/0x200 net/socket.c:768
       splice_to_socket+0xa12/0x10b0 fs/splice.c:889
       do_splice_from fs/splice.c:941 [inline]
       direct_splice_actor+0x120/0x220 fs/splice.c:1164
       splice_direct_to_actor+0x58f/0xc80 fs/splice.c:1108
       do_splice_direct_actor fs/splice.c:1207 [inline]
       do_splice_direct+0x28c/0x3e0 fs/splice.c:1233
       do_sendfile+0x56d/0xdc0 fs/read_write.c:1295
       __do_sys_sendfile64 fs/read_write.c:1362 [inline]
       __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348
       do_syscall_64+0xfb/0x240
       entry_SYSCALL_64_after_hwframe+0x6f/0x77

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&h->lhash2[i].lock);
                               lock(k-sk_lock-AF_INET);
                               lock(&h->lhash2[i].lock);
  lock(k-sk_lock-AF_INET);

 *** DEADLOCK ***

5 locks held by syz-executor.1/24282:
 #0: ffffffff8f381748 (sock_diag_mutex){+.+.}-{3:3}, at: sock_diag_rcv+0x1b/0x40 net/core/sock_diag.c:279
 #1: ffffffff8f3815a8 (sock_diag_table_mutex){+.+.}-{3:3}, at: sock_diag_rcv_msg+0xc6/0x410 net/core/sock_diag.c:259
 #2: ffff88803d754680 (nlk_cb_mutex-SOCK_DIAG){+.+.}-{3:3}, at: netlink_dump+0xde/0xc80 net/netlink/af_netlink.c:2211
 #3: ffffffff8f4650a8 (inet_diag_table_mutex){+.+.}-{3:3}, at: inet_diag_lock_handler net/ipv4/inet_diag.c:63 [inline]
 #3: ffffffff8f4650a8 (inet_diag_table_mutex){+.+.}-{3:3}, at: __inet_diag_dump+0x191/0x3a0 net/ipv4/inet_diag.c:1261
 #4: ffffc90001351ad0 (&h->lhash2[i].lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #4: ffffc90001351ad0 (&h->lhash2[i].lock){+.+.}-{2:2}, at: inet_diag_dump_icsk+0x39f/0x1f80 net/ipv4/inet_diag.c:1038

stack backtrace:
CPU: 0 PID: 24282 Comm: syz-executor.1 Not tainted 6.8.0-rc5-syzkaller-00381-g70ff1fe626a1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
 lock_sock_fast include/net/sock.h:1723 [inline]
 subflow_get_info+0x166/0xd20 net/mptcp/diag.c:28
 tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]
 tcp_diag_get_aux+0x73a/0x830 net/ipv4/tcp_diag.c:137
 inet_sk_diag_fill+0x10ef/0x1e00 net/ipv4/inet_diag.c:345
 inet_diag_dump_icsk+0x55b/0x1f80 net/ipv4/inet_diag.c:1061
 __inet_diag_dump+0x213/0x3a0 net/ipv4/inet_diag.c:1263
 inet_diag_dump_compat+0x1c1/0x2d0 net/ipv4/inet_diag.c:1371
 netlink_dump+0x59d/0xc80 net/netlink/af_netlink.c:2264
 __netlink_dump_start+0x5df/0x790 net/netlink/af_netlink.c:2370
 netlink_dump_start include/linux/netlink.h:338 [inline]
 inet_diag_rcv_msg_compat+0x209/0x4c0 net/ipv4/inet_diag.c:1405
 sock_diag_rcv_msg+0xe9/0x410
 netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2543
 sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:280
 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
 netlink_unicast+0x7ec/0x980 net/netlink/af_netlink.c:1367
 netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x223/0x270 net/socket.c:745
 sock_sendmsg+0x134/0x200 net/socket.c:768
 splice_to_socket+0xa12/0x10b0 fs/splice.c:889
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x120/0x220 fs/splice.c:1164
 splice_direct_to_actor+0x58f/0xc80 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x28c/0x3e0 fs/splice.c:1233
 do_sendfile+0x56d/0xdc0 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7fdde787dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdde858a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fdde79abf80 RCX: 00007fdde787dda9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005
RBP: 00007fdde78ca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000021fd1ee9 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fdde79abf80 R15: 00007ffd1dbd1f48
 </TASK>
BUG: sleeping function called from invalid context at net/core/sock.c:3553
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 24282, name: syz-executor.1
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
INFO: lockdep is turned off.
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 0 PID: 24282 Comm: syz-executor.1 Not tainted 6.8.0-rc5-syzkaller-00381-g70ff1fe626a1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
 __might_resched+0x5d3/0x780 kernel/sched/core.c:10176
 __lock_sock_fast+0x31/0xe0 net/core/sock.c:3553
 lock_sock_fast include/net/sock.h:1725 [inline]
 subflow_get_info+0x172/0xd20 net/mptcp/diag.c:28
 tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]
 tcp_diag_get_aux+0x73a/0x830 net/ipv4/tcp_diag.c:137
 inet_sk_diag_fill+0x10ef/0x1e00 net/ipv4/inet_diag.c:345
 inet_diag_dump_icsk+0x55b/0x1f80 net/ipv4/inet_diag.c:1061
 __inet_diag_dump+0x213/0x3a0 net/ipv4/inet_diag.c:1263
 inet_diag_dump_compat+0x1c1/0x2d0 net/ipv4/inet_diag.c:1371
 netlink_dump+0x59d/0xc80 net/netlink/af_netlink.c:2264
 __netlink_dump_start+0x5df/0x790 net/netlink/af_netlink.c:2370
 netlink_dump_start include/linux/netlink.h:338 [inline]
 inet_diag_rcv_msg_compat+0x209/0x4c0 net/ipv4/inet_diag.c:1405
 sock_diag_rcv_msg+0xe9/0x410
 netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2543
 sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:280
 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
 netlink_unicast+0x7ec/0x980 net/netlink/af_netlink.c:1367
 netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x223/0x270 net/socket.c:745
 sock_sendmsg+0x134/0x200 net/socket.c:768
 splice_to_socket+0xa12/0x10b0 fs/splice.c:889
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x120/0x220 fs/splice.c:1164
 splice_direct_to_actor+0x58f/0xc80 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x28c/0x3e0 fs/splice.c:1233
 do_sendfile+0x56d/0xdc0 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7fdde787dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdde858a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fdde79abf80 RCX: 00007fdde787dda9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005
RBP: 00007fdde78ca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000021fd1ee9 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fdde79abf80 R15: 00007ffd1dbd1f48
 </TASK>