From c77a4b9cffb6215a15196ec499490d116dfad181 Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Sun, 7 Apr 2013 01:51:56 +0000 Subject: [PATCH] llc: Fix missing msg_namelen update in llc_ui_recvmsg() For stream sockets the code misses to update the msg_namelen member to 0 and therefore makes net/socket.c leak the local, uninitialized sockaddr_storage variable to userland -- 128 bytes of kernel stack memory. The msg_namelen update is also missing for datagram sockets in case the socket is shutting down during receive. Fix both issues by setting msg_namelen to 0 early. It will be updated later if we're going to fill the msg_name member. Cc: Arnaldo Carvalho de Melo Signed-off-by: Mathias Krause Signed-off-by: David S. Miller --- net/llc/af_llc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c index 88709882c464..48aaa89253e0 100644 --- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -720,6 +720,8 @@ static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock, int target; /* Read at least this many bytes */ long timeo; + msg->msg_namelen = 0; + lock_sock(sk); copied = -ENOTCONN; if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN)) -- 2.30.2