* [PATCH 6.1.y 1/2] tcp: fix mptcp DSS corruption due to large pmtu xmit
2024-10-18 17:36 [PATCH 6.1.y 0/2] mptcp: fix recent failed backports Matthieu Baerts (NGI0)
@ 2024-10-18 17:36 ` Matthieu Baerts (NGI0)
2024-10-18 17:36 ` [PATCH 6.1.y 2/2] mptcp: prevent MPC handshake on port-based signal endpoints Matthieu Baerts (NGI0)
2024-10-21 9:38 ` [PATCH 6.1.y 0/2] mptcp: fix recent failed backports Greg KH
2 siblings, 0 replies; 4+ messages in thread
From: Matthieu Baerts (NGI0) @ 2024-10-18 17:36 UTC (permalink / raw)
To: mptcp, stable, gregkh
Cc: Paolo Abeni, sashal, syzbot+d1bff73460e33101f0e7, Matthieu Baerts,
Jakub Kicinski
From: Paolo Abeni <pabeni@redhat.com>
commit 4dabcdf581217e60690467a37c956a5b8dbc6bd9 upstream.
Syzkaller was able to trigger a DSS corruption:
TCP: request_sock_subflow_v4: Possible SYN flooding on port [::]:20002. Sending cookies.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5227 at net/mptcp/protocol.c:695 __mptcp_move_skbs_from_subflow+0x20a9/0x21f0 net/mptcp/protocol.c:695
Modules linked in:
CPU: 0 UID: 0 PID: 5227 Comm: syz-executor350 Not tainted 6.11.0-syzkaller-08829-gaf9c191ac2a0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:__mptcp_move_skbs_from_subflow+0x20a9/0x21f0 net/mptcp/protocol.c:695
Code: 0f b6 dc 31 ff 89 de e8 b5 dd ea f5 89 d8 48 81 c4 50 01 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 98 da ea f5 90 <0f> 0b 90 e9 47 ff ff ff e8 8a da ea f5 90 0f 0b 90 e9 99 e0 ff ff
RSP: 0018:ffffc90000006db8 EFLAGS: 00010246
RAX: ffffffff8ba9df18 RBX: 00000000000055f0 RCX: ffff888030023c00
RDX: 0000000000000100 RSI: 00000000000081e5 RDI: 00000000000055f0
RBP: 1ffff110062bf1ae R08: ffffffff8ba9cf12 R09: 1ffff110062bf1b8
R10: dffffc0000000000 R11: ffffed10062bf1b9 R12: 0000000000000000
R13: dffffc0000000000 R14: 00000000700cec61 R15: 00000000000081e5
FS: 000055556679c380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020287000 CR3: 0000000077892000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
move_skbs_to_msk net/mptcp/protocol.c:811 [inline]
mptcp_data_ready+0x29c/0xa90 net/mptcp/protocol.c:854
subflow_data_ready+0x34a/0x920 net/mptcp/subflow.c:1490
tcp_data_queue+0x20fd/0x76c0 net/ipv4/tcp_input.c:5283
tcp_rcv_established+0xfba/0x2020 net/ipv4/tcp_input.c:6237
tcp_v4_do_rcv+0x96d/0xc70 net/ipv4/tcp_ipv4.c:1915
tcp_v4_rcv+0x2dc0/0x37f0 net/ipv4/tcp_ipv4.c:2350
ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233
NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
__netif_receive_skb_one_core net/core/dev.c:5662 [inline]
__netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775
process_backlog+0x662/0x15b0 net/core/dev.c:6107
__napi_poll+0xcb/0x490 net/core/dev.c:6771
napi_poll net/core/dev.c:6840 [inline]
net_rx_action+0x89b/0x1240 net/core/dev.c:6962
handle_softirqs+0x2c5/0x980 kernel/softirq.c:554
do_softirq+0x11b/0x1e0 kernel/softirq.c:455
</IRQ>
<TASK>
__local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline]
__dev_queue_xmit+0x1764/0x3e80 net/core/dev.c:4451
dev_queue_xmit include/linux/netdevice.h:3094 [inline]
neigh_hh_output include/net/neighbour.h:526 [inline]
neigh_output include/net/neighbour.h:540 [inline]
ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:236
ip_local_out net/ipv4/ip_output.c:130 [inline]
__ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:536
__tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466
tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline]
tcp_mtu_probe net/ipv4/tcp_output.c:2547 [inline]
tcp_write_xmit+0x641d/0x6bf0 net/ipv4/tcp_output.c:2752
__tcp_push_pending_frames+0x9b/0x360 net/ipv4/tcp_output.c:3015
tcp_push_pending_frames include/net/tcp.h:2107 [inline]
tcp_data_snd_check net/ipv4/tcp_input.c:5714 [inline]
tcp_rcv_established+0x1026/0x2020 net/ipv4/tcp_input.c:6239
tcp_v4_do_rcv+0x96d/0xc70 net/ipv4/tcp_ipv4.c:1915
sk_backlog_rcv include/net/sock.h:1113 [inline]
__release_sock+0x214/0x350 net/core/sock.c:3072
release_sock+0x61/0x1f0 net/core/sock.c:3626
mptcp_push_release net/mptcp/protocol.c:1486 [inline]
__mptcp_push_pending+0x6b5/0x9f0 net/mptcp/protocol.c:1625
mptcp_sendmsg+0x10bb/0x1b10 net/mptcp/protocol.c:1903
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x1a6/0x270 net/socket.c:745
____sys_sendmsg+0x52a/0x7e0 net/socket.c:2603
___sys_sendmsg net/socket.c:2657 [inline]
__sys_sendmsg+0x2aa/0x390 net/socket.c:2686
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: 0033:0x7fb06e9317f9
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe2cfd4f98 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb06e97f468 RCX: 00007fb06e9317f9
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000005
RBP: 00007fb06e97f446 R08: 0000555500000000 R09: 0000555500000000
R10: 0000555500000000 R11: 0000000000000246 R12: 00007fb06e97f406
R13: 0000000000000001 R14: 00007ffe2cfd4fe0 R15: 0000000000000003
</TASK>
Additionally syzkaller provided a nice reproducer. The repro enables
pmtu on the loopback device, leading to tcp_mtu_probe() generating
very large probe packets.
tcp_can_coalesce_send_queue_head() currently does not check for
mptcp-level invariants, and allowed the creation of cross-DSS probes,
leading to the mentioned corruption.
Address the issue teaching tcp_can_coalesce_send_queue_head() about
mptcp using the tcp_skb_can_collapse(), also reducing the code
duplication.
Fixes: 85712484110d ("tcp: coalesce/collapse must respect MPTCP extensions")
Cc: stable@vger.kernel.org
Reported-by: syzbot+d1bff73460e33101f0e7@syzkaller.appspotmail.com
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/513
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241008-net-mptcp-fallback-fixes-v1-2-c6fb8e93e551@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Conflict in tcp_output.c, because the commit 65249feb6b3d ("net: add
support for skbs with unreadable frags") is not in this version. This
commit is linked to a new feature (Devmem TCP) and introduces a new
condition which causes the conflicts. Resolving this is easy: we can
ignore the missing new condition, and use tcp_skb_can_collapse() like
in the original patch. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
net/ipv4/tcp_output.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 19b5a6179c06..3f54b76bc281 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2312,9 +2312,7 @@ static bool tcp_can_coalesce_send_queue_head(struct sock *sk, int len)
if (len <= skb->len)
break;
- if (unlikely(TCP_SKB_CB(skb)->eor) ||
- tcp_has_tx_tstamp(skb) ||
- !skb_pure_zcopy_same(skb, next))
+ if (tcp_has_tx_tstamp(skb) || !tcp_skb_can_collapse(skb, next))
return false;
len -= skb->len;
--
2.45.2
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 6.1.y 2/2] mptcp: prevent MPC handshake on port-based signal endpoints
2024-10-18 17:36 [PATCH 6.1.y 0/2] mptcp: fix recent failed backports Matthieu Baerts (NGI0)
2024-10-18 17:36 ` [PATCH 6.1.y 1/2] tcp: fix mptcp DSS corruption due to large pmtu xmit Matthieu Baerts (NGI0)
@ 2024-10-18 17:36 ` Matthieu Baerts (NGI0)
2024-10-21 9:38 ` [PATCH 6.1.y 0/2] mptcp: fix recent failed backports Greg KH
2 siblings, 0 replies; 4+ messages in thread
From: Matthieu Baerts (NGI0) @ 2024-10-18 17:36 UTC (permalink / raw)
To: mptcp, stable, gregkh
Cc: Paolo Abeni, sashal, syzbot+f4aacdfef2c6a6529c3e, Cong Wang,
Matthieu Baerts, Mat Martineau, Jakub Kicinski
From: Paolo Abeni <pabeni@redhat.com>
commit 3d041393ea8c815f773020fb4a995331a69c0139 upstream.
Syzkaller reported a lockdep splat:
============================================
WARNING: possible recursive locking detected
6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Not tainted
--------------------------------------------
syz-executor364/5113 is trying to acquire lock:
ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328
but task is already holding lock:
ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(k-slock-AF_INET);
lock(k-slock-AF_INET);
*** DEADLOCK ***
May be due to missing lock nesting notation
7 locks held by syz-executor364/5113:
#0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
#0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x153/0x1b10 net/mptcp/protocol.c:1806
#1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
#1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg_fastopen+0x11f/0x530 net/mptcp/protocol.c:1727
#2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
#2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x5f/0x1b80 net/ipv4/ip_output.c:470
#3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
#3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1390 net/ipv4/ip_output.c:228
#4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
#4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104
#5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
#5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x230/0x5f0 net/ipv4/ip_input.c:232
#6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328
stack backtrace:
CPU: 0 UID: 0 PID: 5113 Comm: syz-executor364 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
check_deadlock kernel/locking/lockdep.c:3061 [inline]
validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855
__lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
__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]
sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328
mptcp_sk_clone_init+0x32/0x13c0 net/mptcp/protocol.c:3279
subflow_syn_recv_sock+0x931/0x1920 net/mptcp/subflow.c:874
tcp_check_req+0xfe4/0x1a20 net/ipv4/tcp_minisocks.c:853
tcp_v4_rcv+0x1c3e/0x37f0 net/ipv4/tcp_ipv4.c:2267
ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233
NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
__netif_receive_skb_one_core net/core/dev.c:5661 [inline]
__netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775
process_backlog+0x662/0x15b0 net/core/dev.c:6108
__napi_poll+0xcb/0x490 net/core/dev.c:6772
napi_poll net/core/dev.c:6841 [inline]
net_rx_action+0x89b/0x1240 net/core/dev.c:6963
handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
do_softirq+0x11b/0x1e0 kernel/softirq.c:455
</IRQ>
<TASK>
__local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline]
__dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450
dev_queue_xmit include/linux/netdevice.h:3105 [inline]
neigh_hh_output include/net/neighbour.h:526 [inline]
neigh_output include/net/neighbour.h:540 [inline]
ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235
ip_local_out net/ipv4/ip_output.c:129 [inline]
__ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535
__tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466
tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6542 [inline]
tcp_rcv_state_process+0x2c32/0x4570 net/ipv4/tcp_input.c:6729
tcp_v4_do_rcv+0x77d/0xc70 net/ipv4/tcp_ipv4.c:1934
sk_backlog_rcv include/net/sock.h:1111 [inline]
__release_sock+0x214/0x350 net/core/sock.c:3004
release_sock+0x61/0x1f0 net/core/sock.c:3558
mptcp_sendmsg_fastopen+0x1ad/0x530 net/mptcp/protocol.c:1733
mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1812
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x1a6/0x270 net/socket.c:745
____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
___sys_sendmsg net/socket.c:2651 [inline]
__sys_sendmmsg+0x3b2/0x740 net/socket.c:2737
__do_sys_sendmmsg net/socket.c:2766 [inline]
__se_sys_sendmmsg net/socket.c:2763 [inline]
__x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
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: 0033:0x7f04fb13a6b9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd651f42d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04fb13a6b9
RDX: 0000000000000001 RSI: 0000000020000d00 RDI: 0000000000000004
RBP: 00007ffd651f4310 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000020000080 R11: 0000000000000246 R12: 00000000000f4240
R13: 00007f04fb187449 R14: 00007ffd651f42f4 R15: 00007ffd651f4300
</TASK>
As noted by Cong Wang, the splat is false positive, but the code
path leading to the report is an unexpected one: a client is
attempting an MPC handshake towards the in-kernel listener created
by the in-kernel PM for a port based signal endpoint.
Such connection will be never accepted; many of them can make the
listener queue full and preventing the creation of MPJ subflow via
such listener - its intended role.
Explicitly detect this scenario at initial-syn time and drop the
incoming MPC request.
Fixes: 1729cf186d8a ("mptcp: create the listening socket for new port")
Cc: stable@vger.kernel.org
Reported-by: syzbot+f4aacdfef2c6a6529c3e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f4aacdfef2c6a6529c3e
Cc: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241014-net-mptcp-mpc-port-endp-v2-1-7faea8e6b6ae@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Conflicts in mib.[ch], because commit 6982826fe5e5 ("mptcp: fallback
to TCP after SYN+MPC drops"), and commit 27069e7cb3d1 ("mptcp: disable
active MPTCP in case of blackhole") are linked to new features, not
available in this version. Resolving the conflicts is easy, simply
adding the new lines declaring the new "endpoint attempt" MIB entry.
Also a conflict in protocol.h, because commit fce68b03086f ("mptcp:
add scheduled in mptcp_subflow_context") is not in this version, and
changes the context by introducing 'scheduled' variable just before.
Also a conflict in pm_netlink.c, because commit 3aa362494170 ("mptcp:
avoid ssock usage in mptcp_pm_nl_create_listen_socket()") is not in
this version, and refactor the function: that's fine, we can still set
pm_listener before doing the 'listen()', taking 'ssock->sk' as 'ssk'
is not defined before this refactoring. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
net/mptcp/mib.c | 1 +
net/mptcp/mib.h | 1 +
net/mptcp/pm_netlink.c | 1 +
net/mptcp/protocol.h | 1 +
net/mptcp/subflow.c | 11 +++++++++++
5 files changed, 15 insertions(+)
diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c
index 691d7c1e8504..fbac6f652701 100644
--- a/net/mptcp/mib.c
+++ b/net/mptcp/mib.c
@@ -15,6 +15,7 @@ static const struct snmp_mib mptcp_snmp_list[] = {
SNMP_MIB_ITEM("MPCapableACKRX", MPTCP_MIB_MPCAPABLEPASSIVEACK),
SNMP_MIB_ITEM("MPCapableFallbackACK", MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK),
SNMP_MIB_ITEM("MPCapableFallbackSYNACK", MPTCP_MIB_MPCAPABLEACTIVEFALLBACK),
+ SNMP_MIB_ITEM("MPCapableEndpAttempt", MPTCP_MIB_MPCAPABLEENDPATTEMPT),
SNMP_MIB_ITEM("MPFallbackTokenInit", MPTCP_MIB_TOKENFALLBACKINIT),
SNMP_MIB_ITEM("MPTCPRetrans", MPTCP_MIB_RETRANSSEGS),
SNMP_MIB_ITEM("MPJoinNoTokenFound", MPTCP_MIB_JOINNOTOKEN),
diff --git a/net/mptcp/mib.h b/net/mptcp/mib.h
index bd3d72e1eb24..ff08d41149f4 100644
--- a/net/mptcp/mib.h
+++ b/net/mptcp/mib.h
@@ -8,6 +8,7 @@ enum linux_mptcp_mib_field {
MPTCP_MIB_MPCAPABLEPASSIVEACK, /* Received third ACK with MP_CAPABLE */
MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK,/* Server-side fallback during 3-way handshake */
MPTCP_MIB_MPCAPABLEACTIVEFALLBACK, /* Client-side fallback during 3-way handshake */
+ MPTCP_MIB_MPCAPABLEENDPATTEMPT, /* Prohibited MPC to port-based endp */
MPTCP_MIB_TOKENFALLBACKINIT, /* Could not init/allocate token */
MPTCP_MIB_RETRANSSEGS, /* Segments retransmitted at the MPTCP-level */
MPTCP_MIB_JOINNOTOKEN, /* Received MP_JOIN but the token was not found */
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 34fab06af744..c5743dc6d18f 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1111,6 +1111,7 @@ static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
}
inet_sk_state_store(newsk, TCP_LISTEN);
+ WRITE_ONCE(mptcp_subflow_ctx(ssock->sk)->pm_listener, true);
err = kernel_listen(ssock, backlog);
if (err) {
pr_warn("kernel_listen error, err=%d", err);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index ee3974b10ef0..d39ad72ac8e8 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -483,6 +483,7 @@ struct mptcp_subflow_context {
close_event_done : 1, /* has done the post-closed part */
__unused : 9;
enum mptcp_data_avail data_avail;
+ bool pm_listener; /* a listener managed by the kernel PM? */
u32 remote_nonce;
u64 thmac;
u32 local_nonce;
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index e77b4e6021e8..884abe3cde53 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -131,6 +131,13 @@ static void subflow_add_reset_reason(struct sk_buff *skb, u8 reason)
}
}
+static int subflow_reset_req_endp(struct request_sock *req, struct sk_buff *skb)
+{
+ SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEENDPATTEMPT);
+ subflow_add_reset_reason(skb, MPTCP_RST_EPROHIBIT);
+ return -EPERM;
+}
+
/* Init mptcp request socket.
*
* Returns an error code if a JOIN has failed and a TCP reset
@@ -162,6 +169,8 @@ static int subflow_check_req(struct request_sock *req,
if (opt_mp_capable) {
SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVE);
+ if (unlikely(listener->pm_listener))
+ return subflow_reset_req_endp(req, skb);
if (opt_mp_join)
return 0;
} else if (opt_mp_join) {
@@ -169,6 +178,8 @@ static int subflow_check_req(struct request_sock *req,
if (mp_opt.backup)
SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINSYNBACKUPRX);
+ } else if (unlikely(listener->pm_listener)) {
+ return subflow_reset_req_endp(req, skb);
}
if (opt_mp_capable && listener->request_mptcp) {
--
2.45.2
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