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Fix crash in DNSSEC code when attempting to verify large RRs.

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This commit is contained in:
Simon Kelley
2014-12-21 16:11:52 +00:00
parent 3267804598
commit 094b5c3d90
2 changed files with 22 additions and 8 deletions
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3
CHANGELOG
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@@ -19,6 +19,9 @@ version 2.73
the answers given by --interface-name. Note that reverse queries
(ie looking for names, given addresses) are not affected.
Thanks to Michael Gorbach for the suggestion.
Fix crash in DNSSEC code with long RRs. Thanks to Marco Davids
for the bug report.
version 2.72

27
src/dnssec.c
View File

@@ -456,16 +456,27 @@ static u16 *get_desc(int type)
/* Return bytes of canonicalised rdata, when the return value is zero, the remaining
data, pointed to by *p, should be used raw. */
static int get_rdata(struct dns_header *header, size_t plen, unsigned char *end, char *buff,
static int get_rdata(struct dns_header *header, size_t plen, unsigned char *end, char *buff, int bufflen,
unsigned char **p, u16 **desc)
{
int d = **desc;
(*desc)++;
/* No more data needs mangling */
if (d == (u16)-1)
return 0;
{
/* If there's more data than we have space for, just return what fits,
we'll get called again for more chunks */
if (end - *p > bufflen)
{
memcpy(buff, *p, bufflen);
*p += bufflen;
return bufflen;
}
return 0;
}
(*desc)++;
if (d == 0 && extract_name(header, plen, p, buff, 1, 0))
/* domain-name, canonicalise */
@@ -560,7 +571,7 @@ static void sort_rrset(struct dns_header *header, size_t plen, u16 *rr_desc, int
if (left1 != 0)
memmove(buff1, buff1 + len1 - left1, left1);
if ((len1 = get_rdata(header, plen, end1, buff1 + left1, &p1, &dp1)) == 0)
if ((len1 = get_rdata(header, plen, end1, buff1 + left1, MAXDNAME - left1, &p1, &dp1)) == 0)
{
quit = 1;
len1 = end1 - p1;
@@ -571,7 +582,7 @@ static void sort_rrset(struct dns_header *header, size_t plen, u16 *rr_desc, int
if (left2 != 0)
memmove(buff2, buff2 + len2 - left2, left2);
if ((len2 = get_rdata(header, plen, end2, buff2 + left2, &p2, &dp2)) == 0)
if ((len2 = get_rdata(header, plen, end2, buff2 + left2, MAXDNAME - left2, &p2, &dp2)) == 0)
{
quit = 1;
len2 = end2 - p2;
@@ -808,7 +819,7 @@ static int validate_rrset(time_t now, struct dns_header *header, size_t plen, in
/* canonicalise rdata and calculate length of same, use name buffer as workspace */
cp = p;
dp = rr_desc;
for (len = 0; (seg = get_rdata(header, plen, end, name, &cp, &dp)) != 0; len += seg);
for (len = 0; (seg = get_rdata(header, plen, end, name, MAXDNAME, &cp, &dp)) != 0; len += seg);
len += end - cp;
len = htons(len);
hash->update(ctx, 2, (unsigned char *)&len);
@@ -816,7 +827,7 @@ static int validate_rrset(time_t now, struct dns_header *header, size_t plen, in
/* Now canonicalise again and digest. */
cp = p;
dp = rr_desc;
while ((seg = get_rdata(header, plen, end, name, &cp, &dp)))
while ((seg = get_rdata(header, plen, end, name, MAXDNAME, &cp, &dp)))
hash->update(ctx, seg, (unsigned char *)name);
if (cp != end)
hash->update(ctx, end - cp, cp);