This is a note to let you know that I've just added the patch titled
mptcp: remove tcp ulp setsockopt support
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mptcp-remove-tcp-ulp-setsockopt-support.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c76a95ca76c5b679ea865f163c52a6d1efda9181
Author: Florian Westphal <fw@xxxxxxxxx>
Date: Tue Dec 14 15:16:01 2021 -0800
mptcp: remove tcp ulp setsockopt support
[ Upstream commit 404cd9a22150f24acf23a8df2ad0c094ba379f57 ]
TCP_ULP setsockopt cannot be used for mptcp because its already
used internally to plumb subflow (tcp) sockets to the mptcp layer.
syzbot managed to trigger a crash for mptcp connections that are
in fallback mode:
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 1 PID: 1083 Comm: syz-executor.3 Not tainted 5.16.0-rc2-syzkaller #0
RIP: 0010:tls_build_proto net/tls/tls_main.c:776 [inline]
[..]
__tcp_set_ulp net/ipv4/tcp_ulp.c:139 [inline]
tcp_set_ulp+0x428/0x4c0 net/ipv4/tcp_ulp.c:160
do_tcp_setsockopt+0x455/0x37c0 net/ipv4/tcp.c:3391
mptcp_setsockopt+0x1b47/0x2400 net/mptcp/sockopt.c:638
Remove support for TCP_ULP setsockopt.
Fixes: d9e4c1291810 ("mptcp: only admit explicitly supported sockopt")
Reported-by: syzbot+1fd9b69cde42967d1add@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Mat Martineau <mathew.j.martineau@xxxxxxxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 8c03afac5ca03..4bb305342fcc7 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -523,7 +523,6 @@ static bool mptcp_supported_sockopt(int level, int optname)
case TCP_NODELAY:
case TCP_THIN_LINEAR_TIMEOUTS:
case TCP_CONGESTION:
- case TCP_ULP:
case TCP_CORK:
case TCP_KEEPIDLE:
case TCP_KEEPINTVL:
