unbound/backport-Integer-overflow-in-sldns_wire2str_pkt_scan.patch
2023-02-22 03:49:55 +00:00

39 lines
1.4 KiB
Diff

From c29b0e0a96c4d281aef40d69a11c564d6ed1a2c6 Mon Sep 17 00:00:00 2001
From: "W.C.A. Wijngaards" <wouter@nlnetlabs.nl>
Date: Thu, 3 Feb 2022 09:03:09 +0100
Subject: [PATCH] - Fix for #611: Integer overflow in sldns_wire2str_pkt_scan.
---
sldns/wire2str.c | 11 +++++++++++
1 files changed, 11 insertions(+)
diff --git a/sldns/wire2str.c b/sldns/wire2str.c
index 6a177ec0b..b70efe299 100644
--- a/sldns/wire2str.c
+++ b/sldns/wire2str.c
@@ -817,6 +817,7 @@ int sldns_wire2str_dname_scan(uint8_t** d, size_t* dlen, char** s, size_t* slen,
unsigned i, counter=0;
unsigned maxcompr = MAX_COMPRESS_PTRS; /* loop detection, max compr ptrs */
int in_buf = 1;
+ size_t dname_len = 0;
if(comprloop) {
if(*comprloop != 0)
maxcompr = 30; /* for like ipv6 reverse name, per label */
@@ -872,6 +873,16 @@ int sldns_wire2str_dname_scan(uint8_t** d, size_t* dlen, char** s, size_t* slen,
labellen = (uint8_t)*dlen;
else if(!in_buf && pos+(size_t)labellen > pkt+pktlen)
labellen = (uint8_t)(pkt + pktlen - pos);
+ dname_len += ((size_t)labellen)+1;
+ if(dname_len > LDNS_MAX_DOMAINLEN) {
+ /* dname_len counts the uncompressed length we have
+ * seen so far, and the domain name has become too
+ * long, prevent the loop from printing overly long
+ * content. */
+ w += sldns_str_print(s, slen,
+ "ErrorDomainNameTooLong");
+ return w;
+ }
for(i=0; i<(unsigned)labellen; i++) {
w += dname_char_print(s, slen, *pos++);
}