BUG/MEDIUM: connection: sanitize PPv2 header length before parsing address information
Previously, if hdr_v2->len was less than the length of the protocol
specific address information we could have read after the end of the
buffer and initialize the sockaddr structure with junk.
Signed-off-by: KOVACS Krisztian <hidden@balabit.com>
[WT: this is only tagged medium since proxy protocol is only used from
trusted sources]
This must be backported to 1.5.
diff --git a/src/connection.c b/src/connection.c
index 3af6d9a..b9f5c42 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -424,6 +424,9 @@
case 0x01: /* PROXY command */
switch (hdr_v2->fam) {
case 0x11: /* TCPv4 */
+ if (ntohs(hdr_v2->len) < PP2_ADDR_LEN_INET)
+ goto bad_header;
+
((struct sockaddr_in *)&conn->addr.from)->sin_family = AF_INET;
((struct sockaddr_in *)&conn->addr.from)->sin_addr.s_addr = hdr_v2->addr.ip4.src_addr;
((struct sockaddr_in *)&conn->addr.from)->sin_port = hdr_v2->addr.ip4.src_port;
@@ -433,6 +436,9 @@
conn->flags |= CO_FL_ADDR_FROM_SET | CO_FL_ADDR_TO_SET;
break;
case 0x21: /* TCPv6 */
+ if (ntohs(hdr_v2->len) < PP2_ADDR_LEN_INET6)
+ goto bad_header;
+
((struct sockaddr_in6 *)&conn->addr.from)->sin6_family = AF_INET6;
memcpy(&((struct sockaddr_in6 *)&conn->addr.from)->sin6_addr, hdr_v2->addr.ip6.src_addr, 16);
((struct sockaddr_in6 *)&conn->addr.from)->sin6_port = hdr_v2->addr.ip6.src_port;