84 lines
3 KiB
Diff
84 lines
3 KiB
Diff
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From 094b5c3d904bae9aeb3206d9f3b8348926b84975 Mon Sep 17 00:00:00 2001
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From: Simon Kelley <simon@thekelleys.org.uk>
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Date: Sun, 21 Dec 2014 16:11:52 +0000
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Subject: [PATCH] Fix crash in DNSSEC code when attempting to verify large RRs.
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---
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src/dnssec.c | 27 +++++++++++++++++++--------
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diff --git a/src/dnssec.c b/src/dnssec.c
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index 69bfc29..3208ac7 100644
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--- a/src/dnssec.c
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+++ b/src/dnssec.c
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@@ -456,16 +456,27 @@ static u16 *get_desc(int type)
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/* Return bytes of canonicalised rdata, when the return value is zero, the remaining
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data, pointed to by *p, should be used raw. */
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-static int get_rdata(struct dns_header *header, size_t plen, unsigned char *end, char *buff,
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+static int get_rdata(struct dns_header *header, size_t plen, unsigned char *end, char *buff, int bufflen,
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unsigned char **p, u16 **desc)
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{
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int d = **desc;
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- (*desc)++;
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-
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/* No more data needs mangling */
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if (d == (u16)-1)
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- return 0;
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+ {
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+ /* If there's more data than we have space for, just return what fits,
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+ we'll get called again for more chunks */
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+ if (end - *p > bufflen)
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+ {
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+ memcpy(buff, *p, bufflen);
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+ *p += bufflen;
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+ return bufflen;
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+ }
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+
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+ return 0;
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+ }
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+
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+ (*desc)++;
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if (d == 0 && extract_name(header, plen, p, buff, 1, 0))
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/* domain-name, canonicalise */
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@@ -560,7 +571,7 @@ static void sort_rrset(struct dns_header *header, size_t plen, u16 *rr_desc, int
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if (left1 != 0)
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memmove(buff1, buff1 + len1 - left1, left1);
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- if ((len1 = get_rdata(header, plen, end1, buff1 + left1, &p1, &dp1)) == 0)
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+ if ((len1 = get_rdata(header, plen, end1, buff1 + left1, MAXDNAME - left1, &p1, &dp1)) == 0)
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{
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quit = 1;
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len1 = end1 - p1;
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@@ -571,7 +582,7 @@ static void sort_rrset(struct dns_header *header, size_t plen, u16 *rr_desc, int
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if (left2 != 0)
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memmove(buff2, buff2 + len2 - left2, left2);
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- if ((len2 = get_rdata(header, plen, end2, buff2 + left2, &p2, &dp2)) == 0)
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+ if ((len2 = get_rdata(header, plen, end2, buff2 + left2, MAXDNAME - left2, &p2, &dp2)) == 0)
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{
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quit = 1;
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len2 = end2 - p2;
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@@ -808,7 +819,7 @@ static int validate_rrset(time_t now, struct dns_header *header, size_t plen, in
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/* canonicalise rdata and calculate length of same, use name buffer as workspace */
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cp = p;
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dp = rr_desc;
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- for (len = 0; (seg = get_rdata(header, plen, end, name, &cp, &dp)) != 0; len += seg);
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+ for (len = 0; (seg = get_rdata(header, plen, end, name, MAXDNAME, &cp, &dp)) != 0; len += seg);
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len += end - cp;
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len = htons(len);
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hash->update(ctx, 2, (unsigned char *)&len);
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@@ -816,7 +827,7 @@ static int validate_rrset(time_t now, struct dns_header *header, size_t plen, in
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/* Now canonicalise again and digest. */
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cp = p;
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dp = rr_desc;
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- while ((seg = get_rdata(header, plen, end, name, &cp, &dp)))
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+ while ((seg = get_rdata(header, plen, end, name, MAXDNAME, &cp, &dp)))
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hash->update(ctx, seg, (unsigned char *)name);
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if (cp != end)
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hash->update(ctx, end - cp, cp);
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--
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2.1.3
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