lib/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2025-07-29 11:41:21 +03:00
Code Activity

Fix assertion failures in resolver (BZ #13013).

Browse Source 
[BZ #13013]
	* resolv/res_query.c(__libc_res_nquery): Assign hp and hp2
	depending n and resplen2 to catch cases where answer
	equals answerp2.
This commit is contained in:
Aurelien Jarno
2012-11-30 15:04:27 -05:00
committed by David S. Miller
parent b062e14ff3
commit cc8bb21c8a
3 changed files with 25 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
resolv/res_query.c
View File

@ -122,6 +122,7 @@ __libc_res_nquery(res_state statp,
int *resplen2)
{
HEADER *hp = (HEADER *) answer;
HEADER *hp2;
int n, use_malloc = 0;
u_int oflags = statp->_flags;
@ -239,25 +240,24 @@ __libc_res_nquery(res_state statp,
/* __libc_res_nsend might have reallocated the buffer. */
hp = (HEADER *) *answerp;
/* We simplify the following tests by assigning HP to HP2. It
is easy to verify that this is the same as ignoring all
tests of HP2. */
HEADER *hp2 = answerp2 ? (HEADER *) *answerp2 : hp;
if (n < (int) sizeof (HEADER) && answerp2 != NULL
&& *resplen2 > (int) sizeof (HEADER))
/* We simplify the following tests by assigning HP to HP2 or
vice versa. It is easy to verify that this is the same as
ignoring all tests of HP or HP2. */
if (answerp2 == NULL || *resplen2 < (int) sizeof (HEADER))
{
/* Special case of partial answer. */
assert (hp != hp2);
hp = hp2;
}
else if (answerp2 != NULL && *resplen2 < (int) sizeof (HEADER)
&& n > (int) sizeof (HEADER))
{
/* Special case of partial answer. */
assert (hp != hp2);
hp2 = hp;
}
else
{
hp2 = (HEADER *) *answerp2;
if (n < (int) sizeof (HEADER))
{
hp = hp2;
}
}
/* Make sure both hp and hp2 are defined */
assert((hp != NULL) && (hp2 != NULL));
if ((hp->rcode != NOERROR || ntohs(hp->ancount) == 0)
&& (hp2->rcode != NOERROR || ntohs(hp2->ancount) == 0)) {