Commit 581e7226 authored by Tom Herbert's avatar Tom Herbert Committed by David S. Miller
Browse files

kcm: Only allow TCP sockets to be attached to a KCM mux 



TCP sockets for IPv4 and IPv6 that are not listeners or in closed
stated are allowed to be attached to a KCM mux.

Fixes: ab7ac4eb ("kcm: Kernel Connection Multiplexor module")
Reported-by: default avatar <syzbot+8865eaff7f9acd593945@syzkaller.appspotmail.com>
Signed-off-by: default avatarTom Herbert <tom@quantonium.net>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d3303a65

net/kcm/kcmsock.c

+7 −2
Original line number Diff line number Diff line
@@ -1387,8 +1387,13 @@ static int kcm_attach(struct socket *sock, struct socket *csock, 
	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);

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