This is a note to let you know that I've just added the patch titled
kcm: Only allow TCP sockets to be attached to a KCM mux
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: kcm-only-allow-tcp-sockets-to-be-attached-to-a-kcm-mux.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 581e7226a5d43f629eb6399a121f85f6a15f81be Mon Sep 17 00:00:00 2001
From: Tom Herbert tom@quantonium.net Date: Wed, 24 Jan 2018 12:35:40 -0800 Subject: kcm: Only allow TCP sockets to be attached to a KCM mux
From: Tom Herbert tom@quantonium.net
commit 581e7226a5d43f629eb6399a121f85f6a15f81be upstream.
TCP sockets for IPv4 and IPv6 that are not listeners or in closed stated are allowed to be attached to a KCM mux.
Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module") Reported-by: syzbot+8865eaff7f9acd593945@syzkaller.appspotmail.com Signed-off-by: Tom Herbert tom@quantonium.net Reviewed-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/kcm/kcmsock.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
--- a/net/kcm/kcmsock.c +++ b/net/kcm/kcmsock.c @@ -1381,8 +1381,13 @@ static int kcm_attach(struct socket *soc if (!csk) return -EINVAL;
- /* We must prevent loops or risk deadlock ! */ - if (csk->sk_family == PF_KCM) + /* Only allow TCP sockets to be attached for now */ + if ((csk->sk_family != AF_INET && csk->sk_family != AF_INET6) || + csk->sk_protocol != IPPROTO_TCP) + return -EOPNOTSUPP; + + /* Don't allow listeners or closed sockets */ + if (csk->sk_state == TCP_LISTEN || csk->sk_state == TCP_CLOSE) return -EOPNOTSUPP;
psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL);
Patches currently in stable-queue which might be from tom@quantonium.net are
queue-4.9/kcm-check-if-sk_user_data-already-set-in-kcm_attach.patch queue-4.9/kcm-only-allow-tcp-sockets-to-be-attached-to-a-kcm-mux.patch