pptp: fix stack info leak in pptp_getname()

pptp_getname() only partially initializes the stack variable sa, particularly only fills the pptp part of the sa_addr union. The code thereby discloses 16 bytes of kernel stack memory via getsockname(). Fix this by memset(0)'ing the union before. Cc: Dmitry Kozlov <[email protected]> Signed-off-by: Mathias Krause <[email protected]> Signed-off-by: David S. Miller <[email protected]>
needcaffeine · Nov 21, 2014 · a5f6fc2 · a5f6fc2
1 parent ee7255a
commit a5f6fc2
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
@@ -506,7 +506,9 @@ static int pptp_getname(struct socket *sock, struct sockaddr *uaddr,
 	int len = sizeof(struct sockaddr_pppox);
 	struct sockaddr_pppox sp;
 
-	sp.sa_family	  = AF_PPPOX;
+	memset(&sp.sa_addr, 0, sizeof(sp.sa_addr));
+
+	sp.sa_family    = AF_PPPOX;
 	sp.sa_protocol  = PX_PROTO_PPTP;
 	sp.sa_addr.pptp = pppox_sk(sock->sk)->proto.pptp.src_addr;