glibc/glibc-resolv_assert.patch

   1 # http://sourceware.org/bugzilla/show_bug.cgi?id=13013
   2
   3 2011-07-21  Aurelien Jarno  <aurel32@debian.org>
   4
   5         * resolv/res_query.c(__libc_res_nquery): Assign hp and hp2
   6         depending n and resplen2 to catch cases where answer
   7         equals answerp2.
   8
   9 diff --git a/resolv/res_query.c b/resolv/res_query.c
  10 index 2f7cfaa..405fa68 100644
  11 --- a/resolv/res_query.c
  12 +++ b/resolv/res_query.c
  13 @@ -122,6 +122,7 @@ __libc_res_nquery(res_state statp,
  14                   int *resplen2)
  15  {
  16         HEADER *hp = (HEADER *) answer;
  17 +       HEADER *hp2;
  18         int n, use_malloc = 0;
  19         u_int oflags = statp->_flags;
  20
  21 @@ -239,26 +240,25 @@ __libc_res_nquery(res_state statp,
  22           /* __libc_res_nsend might have reallocated the buffer.  */
  23           hp = (HEADER *) *answerp;
  24
  25 -       /* We simplify the following tests by assigning HP to HP2.  It
  26 -          is easy to verify that this is the same as ignoring all
  27 -          tests of HP2.  */
  28 -       HEADER *hp2 = answerp2 ? (HEADER *) *answerp2 : hp;
  29 -
  30 -       if (n < (int) sizeof (HEADER) && answerp2 != NULL
  31 -           && *resplen2 > (int) sizeof (HEADER))
  32 +       /* We simplify the following tests by assigning HP to HP2 or
  33 +          vice versa.  It is easy to verify that this is the same as
  34 +          ignoring all tests of HP or HP2.  */
  35 +       if (answerp2 == NULL || *resplen2 < (int) sizeof (HEADER))
  36           {
  37 -           /* Special case of partial answer.  */
  38 -           assert (hp != hp2);
  39 -           hp = hp2;
  40 +           hp2 = hp;
  41           }
  42 -       else if (answerp2 != NULL && *resplen2 < (int) sizeof (HEADER)
  43 -                && n > (int) sizeof (HEADER))
  44 +       else
  45           {
  46 -           /* Special case of partial answer.  */
  47 -           assert (hp != hp2);
  48 -           hp2 = hp;
  49 +           hp2 = (HEADER *) *answerp2;
  50 +           if (n < (int) sizeof (HEADER))
  51 +             {
  52 +               hp = hp2;
  53 +             }
  54           }
  55
  56 +       /* Make sure both hp and hp2 are defined */
  57 +       assert((hp != NULL) && (hp2 != NULL));
  58 +
  59         if ((hp->rcode != NOERROR || ntohs(hp->ancount) == 0)
  60             && (hp2->rcode != NOERROR || ntohs(hp2->ancount) == 0)) {
  61  #ifdef DEBUG