From: Mathias Krause Date: Sun, 7 Apr 2013 01:51:48 +0000 (+0000) Subject: ax25: fix info leak via msg_name in ax25_recvmsg() X-Git-Tag: v2.6.34.15~186 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c327aec64e7ddd03b70e357331de5350ed2fe220;p=thirdparty%2Fkernel%2Fstable.git ax25: fix info leak via msg_name in ax25_recvmsg() commit ef3313e84acbf349caecae942ab3ab731471f1a1 upstream. 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 Signed-off-by: Paul Gortmaker --- diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c index 12c350c637171..d082b6db6b813 100644 --- a/net/ax25/af_ax25.c +++ b/net/ax25/af_ax25.c @@ -1655,6 +1655,7 @@ 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;