[syzbot] [mptcp?] WARNING in subflow_data_ready (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 6613476e225e Linux 6.8-rc1
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1200cf0de80000
kernel config: https://syzkaller.appspot.com/x/.config?x=f9804db253bdfc61
dashboard link: https://syzkaller.appspot.com/bug?extid=732ab7be796ec0d104ac
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=111fe2bfe80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17abc23be80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/cdad5c52fcde/disk-6613476e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/14491fee3433/vmlinux-6613476e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/953a5864daf4/bzImage-6613476e.xz

The issue was bisected to:

commit 14c56686a64c65ba716ff48f1f4b19c85f4cb2a9
Author: Geliang Tang <gelian...@suse.com>
Date: Wed Oct 18 18:23:55 2023 +0000

mptcp: avoid sending RST when closing the initial subflow

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=159a9427e80000
final oops: https://syzkaller.appspot.com/x/report.txt?x=179a9427e80000
console output: https://syzkaller.appspot.com/x/log.txt?x=139a9427e80000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+732ab7...@syzkaller.appspotmail.com
Fixes: 14c56686a64c ("mptcp: avoid sending RST when closing the initial subflow")

------------[ cut here ]------------
WARNING: CPU: 1 PID: 5097 at net/mptcp/subflow.c:1412 subflow_data_ready+0x3a0/0x690 net/mptcp/subflow.c:1412
Modules linked in:
CPU: 1 PID: 5097 Comm: syz-executor260 Not tainted 6.8.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:subflow_data_ready+0x3a0/0x690 net/mptcp/subflow.c:1412
Code: 89 ee e8 13 ff 14 f7 40 84 ed 75 21 e8 d9 03 15 f7 44 89 fe bf 07 00 00 00 e8 3c ff 14 f7 41 83 ff 07 74 09 e8 c1 03 15 f7 90 <0f> 0b 90 e8 b8 03 15 f7 48 89 df e8 70 b2 ff ff 31 ff 89 c5 89 c6
RSP: 0018:ffffc90003b2ed38 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88807f306200 RCX: ffffffff8a731e94
RDX: ffff888028d80000 RSI: ffffffff8a731e9f RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000007
R10: 000000000000000b R11: 0000000000000000 R12: 1ffff92000765da7
R13: ffff88802acd5080 R14: ffff88802b24d200 R15: 000000000000000b
FS: 00007fc7f15026c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000040 CR3: 0000000028426000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
tcp_data_ready+0x14c/0x5b0 net/ipv4/tcp_input.c:5143
tcp_data_queue+0x19bb/0x5190 net/ipv4/tcp_input.c:5223
tcp_rcv_state_process+0x11d2/0x4e30 net/ipv4/tcp_input.c:6859
tcp_v4_do_rcv+0x369/0xa10 net/ipv4/tcp_ipv4.c:1929
sk_backlog_rcv include/net/sock.h:1092 [inline]
__release_sock+0x132/0x3b0 net/core/sock.c:2972
release_sock+0x5a/0x1f0 net/core/sock.c:3538
__mptcp_close_ssk+0xb12/0xfd0 net/mptcp/protocol.c:2421
mptcp_pm_nl_rm_addr_or_subflow+0x29e/0xa30 net/mptcp/pm_netlink.c:818
mptcp_pm_remove_subflow+0x34/0xa0 net/mptcp/pm.c:69
mptcp_pm_remove_addrs_and_subflows+0x5a2/0x6a0 net/mptcp/pm_netlink.c:1558
mptcp_nl_remove_addrs_list net/mptcp/pm_netlink.c:1575 [inline]
mptcp_pm_nl_flush_addrs_doit+0x3fe/0x6e0 net/mptcp/pm_netlink.c:1616
genl_family_rcv_msg_doit+0x1fc/0x2e0 net/netlink/genetlink.c:1113
genl_family_rcv_msg net/netlink/genetlink.c:1193 [inline]
genl_rcv_msg+0x561/0x800 net/netlink/genetlink.c:1208
netlink_rcv_skb+0x16b/0x440 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+0x53b/0x810 net/netlink/af_netlink.c:1367
netlink_sendmsg+0x8b7/0xd70 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0xd5/0x180 net/socket.c:745
____sys_sendmsg+0x6ac/0x940 net/socket.c:2584
___sys_sendmsg+0x135/0x1d0 net/socket.c:2638
__sys_sendmsg+0x117/0x1e0 net/socket.c:2667
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7fc7f1566d89
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 1a 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:00007fc7f1502228 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc7f15f1438 RCX: 00007fc7f1566d89
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000006
RBP: 00007fc7f15f1430 R08: 00007fc7f15026c0 R09: 00007fc7f15026c0
R10: 00007fc7f15026c0 R11: 0000000000000246 R12: 00007fc7f15f143c
R13: 00007fc7f15bd610 R14: 6d705f706374706d R15: 00007fff17bfe738
</TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[Paolo Abeni]

I forgot to mention this is looks like a legit mptcp-related issue.

There is a fix for this in the mptcp devel branch that should land here
somewhat soonish.

Cheers,

Paolo