2002-11-14 Paul Eggert <eggert@twionsun.com>
authorroland <roland>
Mon, 18 Nov 2002 04:10:08 +0000 (04:10 +0000)
committerroland <roland>
Mon, 18 Nov 2002 04:10:08 +0000 (04:10 +0000)
        * resolv/nss_dns/dns-network.c (getanswer_r): Check for buffer
        overflow when skipping the question part and when unpacking
        aliases.

resolv/nss_dns/dns-network.c

index 5956c84..fdab996 100644 (file)
@@ -283,7 +283,15 @@ getanswer_r (const querybuf *answer, int anslen, struct netent *result,
 
   /* Skip the question part.  */
   while (question_count-- > 0)
-    cp += __dn_skipname (cp, end_of_message) + QFIXEDSZ;
+    {
+      int n = __dn_skipname (cp, end_of_message);
+      if (n < 0 || end_of_message - (cp + n) < QFIXEDSZ)
+       {
+         __set_h_errno (NO_RECOVERY);
+         return NSS_STATUS_UNAVAIL;
+       }
+      cp += n + QFIXEDSZ;
+    }
 
   alias_pointer = result->n_aliases = &net_data->aliases[0];
   *alias_pointer = NULL;
@@ -344,12 +352,15 @@ getanswer_r (const querybuf *answer, int anslen, struct netent *result,
              return NSS_STATUS_UNAVAIL;
            }
          cp += n;
-         *alias_pointer++ = bp;
-         n = strlen (bp) + 1;
-         bp += n;
-         linebuflen -= n;
-         result->n_addrtype = class == C_IN ? AF_INET : AF_UNSPEC;
-         ++have_answer;
+         if (alias_pointer + 2 < &net_data->aliases[MAX_NR_ALIASES])
+           {
+             *alias_pointer++ = bp;
+             n = strlen (bp) + 1;
+             bp += n;
+             linebuflen -= n;
+             result->n_addrtype = class == C_IN ? AF_INET : AF_UNSPEC;
+             ++have_answer;
+           }
        }
     }