This is a note to let you know that I've just added the patch titled
mptcp: avoid unneeded __mptcp_nmpc_socket() usage
to the 6.1-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-avoid-unneeded-__mptcp_nmpc_socket-usage.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4c959457f74aba4c8b161c0cc4843b1b690080ea
Author: Paolo Abeni <pabeni@xxxxxxxxxx>
Date: Fri Apr 14 16:08:01 2023 +0200
mptcp: avoid unneeded __mptcp_nmpc_socket() usage
[ Upstream commit 617612316953093bc859890e405e1b550c27d840 ]
In a few spots, the mptcp code invokes the __mptcp_nmpc_socket() helper
multiple times under the same socket lock scope. Additionally, in such
places, the socket status ensures that there is no MP capable handshake
running.
Under the above condition we can replace the later __mptcp_nmpc_socket()
helper invocation with direct access to the msk->subflow pointer and
better document such access is not supposed to fail with WARN().
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Reviewed-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Signed-off-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Stable-dep-of: 5b825727d087 ("mptcp: add annotations around msk->subflow accesses")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index ea46a5cb1c30f..fecee0a850d65 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3172,7 +3172,7 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err,
struct socket *listener;
struct sock *newsk;
- listener = __mptcp_nmpc_socket(msk);
+ listener = msk->subflow;
if (WARN_ON_ONCE(!listener)) {
*err = -EINVAL;
return NULL;
@@ -3398,7 +3398,7 @@ static int mptcp_get_port(struct sock *sk, unsigned short snum)
struct mptcp_sock *msk = mptcp_sk(sk);
struct socket *ssock;
- ssock = __mptcp_nmpc_socket(msk);
+ ssock = msk->subflow;
pr_debug("msk=%p, subflow=%p", msk, ssock);
if (WARN_ON_ONCE(!ssock))
return -EINVAL;
@@ -3746,7 +3746,10 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock,
pr_debug("msk=%p", msk);
- ssock = __mptcp_nmpc_socket(msk);
+ /* buggy applications can call accept on socket states other then LISTEN
+ * but no need to allocate the first subflow just to error out.
+ */
+ ssock = msk->subflow;
if (!ssock)
return -EINVAL;
