Avoid infinite loop in nss_dns getnetbyname [BZ #17630]

diff --git a/ChangeLog b/ChangeLog
index a0a11e8..ee147e2 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2014-12-16  Florian Weimer  <fweimer@redhat.com>
+
+       [BZ #17630]
+       * resolv/nss_dns/dns-network.c (getanswer_r): Iterate over alias
+       names.
+
 2014-12-16  Allan McRae  <allan@archlinux.org>
 
        * stdio-common/Makefile (tests): Re-add bug26.

diff --git a/NEWS b/NEWS
index 3556ecd..11121ca 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -13,8 +13,8 @@ Version 2.21
   15884, 16469, 16617, 16619, 16657, 16740, 16857, 17192, 17266, 17344,
   17363, 17370, 17371, 17411, 17460, 17475, 17485, 17501, 17506, 17508,
   17522, 17555, 17570, 17571, 17572, 17573, 17574, 17581, 17582, 17583,
-  17584, 17585, 17589, 17594, 17601, 17608, 17616, 17625, 17633, 17634,
-  17647, 17653, 17657, 17664, 17665, 17668, 17682.
+  17584, 17585, 17589, 17594, 17601, 17608, 17616, 17625, 17630, 17633,
+  17634, 17647, 17653, 17657, 17664, 17665, 17668, 17682.
 
 * CVE-2104-7817 The wordexp function could ignore the WRDE_NOCMD flag
   under certain input conditions resulting in the execution of a shell for
@@ -25,6 +25,9 @@ Version 2.21
 * CVE-2012-3406 printf-style functions could run into a stack overflow when
   processing format strings with a large number of format specifiers.
 
+* The nss_dns implementation of getnetbyname could run into an infinite loop
+  if the DNS response contained a PTR record of an unexpected format.
+
 * The minimum GCC version that can be used to build this version of the GNU
   C Library is GCC 4.6.  Older GCC versions, and non-GNU compilers, can
   still be used to compile programs using the GNU C Library.

diff --git a/resolv/nss_dns/dns-network.c b/resolv/nss_dns/dns-network.c
index 0a77c8b..08cf0a6 100644 (file)
--- a/resolv/nss_dns/dns-network.c
+++ b/resolv/nss_dns/dns-network.c
@@ -398,8 +398,8 @@ getanswer_r (const querybuf *answer, int anslen, struct netent *result,
 
        case BYNAME:
          {
-           char **ap = result->n_aliases++;
-           while (*ap != NULL)
+           char **ap;
+           for (ap = result->n_aliases; *ap != NULL; ++ap)
              {
                /* Check each alias name for being of the forms:
                   4.3.2.1.in-addr.arpa         = net 1.2.3.4