From: Florian Weimer <fweimer@redhat.com>
Date: Mon, 2 May 2016 14:04:32 +0000 (+0200)
Subject: hesiod: Avoid heap overflow in get_txt_records [BZ #20031]
X-Git-Tag: glibc-2.24~294
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8a03ccbb77f52ec4b55062eeedddb8daec1a33e4;p=thirdparty%2Fglibc.git

hesiod: Avoid heap overflow in get_txt_records [BZ #20031]
---

diff --git a/ChangeLog b/ChangeLog
index 1149fd30e26..d7044ea43da 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2016-05-02  Florian Weimer  <fweimer@redhat.com>
+
+	[BZ #20031]
+	* hesiod/hesiod.c (get_txt_records): Return error if TXT record is
+	completely empty.
+
 2016-05-02  Florian Weimer  <fweimer@redhat.com>
 
 	[BZ #19573]
diff --git a/hesiod/hesiod.c b/hesiod/hesiod.c
index 6ecbad11cc7..c2925a0f99e 100644
--- a/hesiod/hesiod.c
+++ b/hesiod/hesiod.c
@@ -398,7 +398,7 @@ get_txt_records(struct hesiod_p *ctx, int class, const char *name) {
 		cp += INT16SZ + INT32SZ;	/* skip the ttl, too */
 		rr.dlen = ns_get16(cp);
 		cp += INT16SZ;
-		if (cp + rr.dlen > eom) {
+		if (rr.dlen == 0 || cp + rr.dlen > eom) {
 			__set_errno(EMSGSIZE);
 			goto cleanup;
 		}