From ef3313e84acbf349caecae942ab3ab731471f1a1 Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Sun, 7 Apr 2013 01:51:48 +0000 Subject: [PATCH] ax25: fix info leak via msg_name in ax25_recvmsg() When msg_namelen is non-zero the sockaddr info gets filled out, as requested, but the code fails to initialize the padding bytes of struct sockaddr_ax25 inserted by the compiler for alignment. Additionally the msg_namelen value is updated to sizeof(struct full_sockaddr_ax25) but is not always filled up to this size. Both issues lead to the fact that the code will leak uninitialized kernel stack bytes in net/socket.c. Fix both issues by initializing the memory with memset(0). Cc: Ralf Baechle Signed-off-by: Mathias Krause Signed-off-by: David S. Miller --- net/ax25/af_ax25.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c index 7b11f8bc5071..e277e38f736b 100644 --- a/net/ax25/af_ax25.c +++ b/net/ax25/af_ax25.c @@ -1642,6 +1642,7 @@ static int ax25_recvmsg(struct kiocb *iocb, struct socket *sock, ax25_address src; const unsigned char *mac = skb_mac_header(skb); + memset(sax, 0, sizeof(struct full_sockaddr_ax25)); ax25_addr_parse(mac + 1, skb->data - mac - 1, &src, NULL, &digi, NULL, NULL); sax->sax25_family = AF_AX25; -- 2.20.1