nss_dns: Fix assertion failure in _nss_dns_getcanonname_r [BZ #19865]

(cherry picked from commit d29fb41f4431ca35ea360498ef9d37558ce90d76)

diff --git a/ChangeLog b/ChangeLog
index 85a0733097267266dce9678df765567f6ca69ad3..7f4794fc40400daf4e656fff248539bbe9746ac1 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2016-04-11  Florian Weimer  <fweimer@redhat.com>
+
+       [BZ #19865]
+       * resolv/nss_dns/dns-canon.c (_nss_dns_getcanonname_r): Restore
+       original buffer before retry.
+
 2016-04-14  Florian Weimer  <fweimer@redhat.com>
 
        * malloc/arena.c (__malloc_fork_lock_parent)

diff --git a/resolv/nss_dns/dns-canon.c b/resolv/nss_dns/dns-canon.c
index 27255fda58c78fe2fed86eb3a1c4ca862c0f736c..fd73f19984c45cf14f67fb17891541b12599980e 100644 (file)
--- a/resolv/nss_dns/dns-canon.c
+++ b/resolv/nss_dns/dns-canon.c
@@ -144,6 +144,13 @@ _nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen,
              ptr += sizeof (uint16_t) + __ns_get16 (ptr);
            }
        }
+
+      /* Restore original buffer before retry.  */
+      if (ansp.ptr != buf)
+       {
+         free (ansp.ptr);
+         ansp.ptr = buf;
+       }
     }
 
  out: