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Properly fix memory leak in _nss_dns_gethostbyname4_r with big DNS answer 

Instead of trying to guess whether the second buffer needs to be freed
set a flag at the place it is allocated
This commit is contained in:
Andreas Schwab 2014-02-18 10:57:25 +01:00
parent c6af2d896c
commit ab09bf616a
8 changed files with 95 additions and 49 deletions
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37
ChangeLog
View File

@ -1,3 +1,40 @@
2014-02-18 Andreas Schwab <schwab@suse.de>
[BZ #16574]
* resolv/res_send.c (send_vc): Add parameter ansp2_malloced.
Store non-zero if the second buffer was newly allocated.
(send_dg): Likewise.
(__libc_res_nsend): Add parameter ansp2_malloced and pass it down
to send_vc and send_dg.
(res_nsend): Pass NULL for ansp2_malloced.
* resolv/res_query.c (__libc_res_nquery): Add parameter
answerp2_malloced and pass it down to __libc_res_nsend.
(res_nquery): Pass additional NULL to __libc_res_nquery.
(__libc_res_nsearch): Add parameter answerp2_malloced and pass it
down to __libc_res_nquery and __libc_res_nquerydomain. Deallocate
second answer buffer if answerp2_malloced was set.
(res_nsearch): Pass additional NULL to __libc_res_nsearch.
(__libc_res_nquerydomain): Add parameter
answerp2_malloced and pass it down to __libc_res_nquery.
(res_nquerydomain): Pass additional NULL to
__libc_res_nquerydomain.
* resolv/nss_dns/dns-network.c (_nss_dns_getnetbyname_r): Pass
additional NULL to __libc_res_nsend and __libc_res_nquery.
* resolv/nss_dns/dns-host.c (_nss_dns_gethostbyname3_r): Pass
additional NULL to __libc_res_nsearch.
(_nss_dns_gethostbyname4_r): Revert last change. Use new
parameter of __libc_res_nsearch to check for separately allocated
second buffer.
(_nss_dns_gethostbyaddr2_r): Pass additional NULL to
__libc_res_nquery.
* resolv/nss_dns/dns-canon.c (_nss_dns_getcanonname_r): Pass
additional NULL to __libc_res_nquery.
* resolv/gethnamaddr.c (gethostbyname2): Pass additional NULL to
__libc_res_nsearch.
(gethostbyaddr): Pass additional NULL to __libc_res_nquery.
* include/resolv.h: Update prototypes of __libc_res_nquery,
__libc_res_nsearch, __libc_res_nsend.
2014-02-18 Joseph Myers <joseph@codesourcery.com>
* math/auto-libm-test-in: Add tests of fma.

6
include/resolv.h
View File

@ -48,11 +48,11 @@ libc_hidden_proto (__res_randomid)
libc_hidden_proto (__res_state)
int __libc_res_nquery (res_state, const char *, int, int, u_char *, int,
u_char **, u_char **, int *, int *);
u_char **, u_char **, int *, int *, int *);
int __libc_res_nsearch (res_state, const char *, int, int, u_char *, int,
u_char **, u_char **, int *, int *);
u_char **, u_char **, int *, int *, int *);
int __libc_res_nsend (res_state, const u_char *, int, const u_char *, int,
u_char *, int, u_char **, u_char **, int *, int *)
u_char *, int, u_char **, u_char **, int *, int *, int *)
attribute_hidden;
libresolv_hidden_proto (_sethtent)

6
resolv/gethnamaddr.c
View File

@ -621,7 +621,7 @@ gethostbyname2(name, af)
buf.buf = origbuf = (querybuf *) alloca (1024);
if ((n = __libc_res_nsearch(&_res, name, C_IN, type, buf.buf->buf, 1024,
&buf.ptr, NULL, NULL, NULL)) < 0) {
&buf.ptr, NULL, NULL, NULL, NULL)) < 0) {
if (buf.buf != origbuf)
free (buf.buf);
Dprintf("res_nsearch failed (%d)\n", n);
@ -716,12 +716,12 @@ gethostbyaddr(addr, len, af)
buf.buf = orig_buf = (querybuf *) alloca (1024);
n = __libc_res_nquery(&_res, qbuf, C_IN, T_PTR, buf.buf->buf, 1024,
&buf.ptr, NULL, NULL, NULL);
&buf.ptr, NULL, NULL, NULL, NULL);
if (n < 0 && af == AF_INET6 && (_res.options & RES_NOIP6DOTINT) == 0) {
strcpy(qp, "ip6.int");
n = __libc_res_nquery(&_res, qbuf, C_IN, T_PTR, buf.buf->buf,
buf.buf != orig_buf ? MAXPACKET : 1024,
&buf.ptr, NULL, NULL, NULL);
&buf.ptr, NULL, NULL, NULL, NULL);
}
if (n < 0) {
if (buf.buf != orig_buf)

2
resolv/nss_dns/dns-canon.c
View File

@ -62,7 +62,7 @@ _nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen,
{
int r = __libc_res_nquery (&_res, name, ns_c_in, qtypes[i],
buf, sizeof (buf), &ansp.ptr, NULL, NULL,
NULL);
NULL, NULL);
if (r > 0)
{
/* We need to decode the response. Just one question record.

23
resolv/nss_dns/dns-host.c
View File

@ -190,7 +190,7 @@ _nss_dns_gethostbyname3_r (const char *name, int af, struct hostent *result,
host_buffer.buf = orig_host_buffer = (querybuf *) alloca (1024);
n = __libc_res_nsearch (&_res, name, C_IN, type, host_buffer.buf->buf,
1024, &host_buffer.ptr, NULL, NULL, NULL);
1024, &host_buffer.ptr, NULL, NULL, NULL, NULL);
if (n < 0)
{
switch (errno)
@ -225,7 +225,7 @@ _nss_dns_gethostbyname3_r (const char *name, int af, struct hostent *result,
n = __libc_res_nsearch (&_res, name, C_IN, T_A, host_buffer.buf->buf,
host_buffer.buf != orig_host_buffer
? MAXPACKET : 1024, &host_buffer.ptr,
NULL, NULL, NULL);
NULL, NULL, NULL, NULL);
if (n < 0)
{
@ -298,23 +298,23 @@ _nss_dns_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
name = cp;
}
int anslen = 2048;
union
{
querybuf *buf;
u_char *ptr;
} host_buffer;
querybuf *orig_host_buffer;
host_buffer.buf = orig_host_buffer = (querybuf *) alloca (anslen);
host_buffer.buf = orig_host_buffer = (querybuf *) alloca (2048);
u_char *ans2p = NULL;
int nans2p = 0;
int resplen2 = 0;
int ans2p_malloced = 0;
int olderr = errno;
enum nss_status status;
int n = __libc_res_nsearch (&_res, name, C_IN, T_UNSPEC,
host_buffer.buf->buf, anslen, &host_buffer.ptr,
&ans2p, &nans2p, &resplen2);
host_buffer.buf->buf, 2048, &host_buffer.ptr,
&ans2p, &nans2p, &resplen2, &ans2p_malloced);
if (n >= 0)
{
status = gaih_getanswer (host_buffer.buf, n, (const querybuf *) ans2p,
@ -351,10 +351,7 @@ _nss_dns_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
}
/* Check whether ans2p was separately allocated. */
if (host_buffer.buf != orig_host_buffer)
anslen = MAXPACKET;
if (ans2p != NULL
&& (ans2p < host_buffer.ptr || ans2p >= host_buffer.ptr + anslen))
if (ans2p_malloced)
free (ans2p);
if (host_buffer.buf != orig_host_buffer)
@ -465,7 +462,7 @@ _nss_dns_gethostbyaddr2_r (const void *addr, socklen_t len, int af,
strcpy (qp, "].ip6.arpa");
n = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR,
host_buffer.buf->buf, 1024, &host_buffer.ptr,
NULL, NULL, NULL);
NULL, NULL, NULL, NULL);
if (n >= 0)
goto got_it_already;
}
@ -486,14 +483,14 @@ _nss_dns_gethostbyaddr2_r (const void *addr, socklen_t len, int af,
}
n = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, host_buffer.buf->buf,
1024, &host_buffer.ptr, NULL, NULL, NULL);
1024, &host_buffer.ptr, NULL, NULL, NULL, NULL);
if (n < 0 && af == AF_INET6 && (_res.options & RES_NOIP6DOTINT) == 0)
{
strcpy (qp, "ip6.int");
n = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, host_buffer.buf->buf,
host_buffer.buf != orig_host_buffer
? MAXPACKET : 1024, &host_buffer.ptr,
NULL, NULL, NULL);
NULL, NULL, NULL, NULL);
}
if (n < 0)
{

4
resolv/nss_dns/dns-network.c
View File

@ -129,7 +129,7 @@ _nss_dns_getnetbyname_r (const char *name, struct netent *result,
net_buffer.buf = orig_net_buffer = (querybuf *) alloca (1024);
anslen = __libc_res_nsearch (&_res, qbuf, C_IN, T_PTR, net_buffer.buf->buf,
1024, &net_buffer.ptr, NULL, NULL, NULL);
1024, &net_buffer.ptr, NULL, NULL, NULL, NULL);
if (anslen < 0)
{
/* Nothing found. */
@ -205,7 +205,7 @@ _nss_dns_getnetbyaddr_r (uint32_t net, int type, struct netent *result,
net_buffer.buf = orig_net_buffer = (querybuf *) alloca (1024);
anslen = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, net_buffer.buf->buf,
1024, &net_buffer.ptr, NULL, NULL, NULL);
1024, &net_buffer.ptr, NULL, NULL, NULL, NULL);
if (anslen < 0)
{
/* Nothing found. */

45
resolv/res_query.c
View File

@ -98,7 +98,7 @@ static int
__libc_res_nquerydomain(res_state statp, const char *name, const char *domain,
int class, int type, u_char *answer, int anslen,
u_char **answerp, u_char **answerp2, int *nanswerp2,
int *resplen2);
int *resplen2, int *answerp2_malloced);
/*
* Formulate a normal query, send, and await answer.
@ -119,7 +119,8 @@ __libc_res_nquery(res_state statp,
u_char **answerp, /* if buffer needs to be enlarged */
u_char **answerp2,
int *nanswerp2,
int *resplen2)
int *resplen2,
int *answerp2_malloced)
{
HEADER *hp = (HEADER *) answer;
HEADER *hp2;
@ -224,7 +225,8 @@ __libc_res_nquery(res_state statp,
}
assert (answerp == NULL || (void *) *answerp == (void *) answer);
n = __libc_res_nsend(statp, query1, nquery1, query2, nquery2, answer,
anslen, answerp, answerp2, nanswerp2, resplen2);
anslen, answerp, answerp2, nanswerp2, resplen2,
answerp2_malloced);
if (use_malloc)
free (buf);
if (n < 0) {
@ -316,7 +318,7 @@ res_nquery(res_state statp,
int anslen) /* size of answer buffer */
{
return __libc_res_nquery(statp, name, class, type, answer, anslen,
NULL, NULL, NULL, NULL);
NULL, NULL, NULL, NULL, NULL);
}
libresolv_hidden_def (res_nquery)
@ -335,7 +337,8 @@ __libc_res_nsearch(res_state statp,
u_char **answerp,
u_char **answerp2,
int *nanswerp2,
int *resplen2)
int *resplen2,
int *answerp2_malloced)
{
const char *cp, * const *domain;
HEADER *hp = (HEADER *) answer;
@ -360,7 +363,7 @@ __libc_res_nsearch(res_state statp,
if (!dots && (cp = res_hostalias(statp, name, tmp, sizeof tmp))!= NULL)
return (__libc_res_nquery(statp, cp, class, type, answer,
anslen, answerp, answerp2,
nanswerp2, resplen2));
nanswerp2, resplen2, answerp2_malloced));
#ifdef DEBUG
if (statp->options & RES_DEBUG)
@ -377,7 +380,8 @@ __libc_res_nsearch(res_state statp,
if (dots >= statp->ndots || trailing_dot) {
ret = __libc_res_nquerydomain(statp, name, NULL, class, type,
answer, anslen, answerp,
answerp2, nanswerp2, resplen2);
answerp2, nanswerp2, resplen2,
answerp2_malloced);
if (ret > 0 || trailing_dot)
return (ret);
saved_herrno = h_errno;
@ -386,11 +390,11 @@ __libc_res_nsearch(res_state statp,
answer = *answerp;
anslen = MAXPACKET;
}
if (answerp2
&& (*answerp2 < answer || *answerp2 >= answer + anslen))
if (answerp2 && *answerp2_malloced)
{
free (*answerp2);
*answerp2 = NULL;
*answerp2_malloced = 0;
}
}
@ -417,7 +421,7 @@ __libc_res_nsearch(res_state statp,
class, type,
answer, anslen, answerp,
answerp2, nanswerp2,
resplen2);
resplen2, answerp2_malloced);
if (ret > 0)
return (ret);
@ -425,12 +429,11 @@ __libc_res_nsearch(res_state statp,
answer = *answerp;
anslen = MAXPACKET;
}
if (answerp2
&& (*answerp2 < answer
|| *answerp2 >= answer + anslen))
if (answerp2 && *answerp2_malloced)
{
free (*answerp2);
*answerp2 = NULL;
*answerp2_malloced = 0;
}
/*
@ -486,7 +489,8 @@ __libc_res_nsearch(res_state statp,
&& !(tried_as_is || root_on_list)) {
ret = __libc_res_nquerydomain(statp, name, NULL, class, type,
answer, anslen, answerp,
answerp2, nanswerp2, resplen2);
answerp2, nanswerp2, resplen2,
answerp2_malloced);
if (ret > 0)
return (ret);
}
@ -498,10 +502,11 @@ __libc_res_nsearch(res_state statp,
* else send back meaningless H_ERRNO, that being the one from
* the last DNSRCH we did.
*/
if (answerp2 && (*answerp2 < answer || *answerp2 >= answer + anslen))
if (answerp2 && *answerp2_malloced)
{
free (*answerp2);
*answerp2 = NULL;
*answerp2_malloced = 0;
}
if (saved_herrno != -1)
RES_SET_H_ERRNO(statp, saved_herrno);
@ -521,7 +526,7 @@ res_nsearch(res_state statp,
int anslen) /* size of answer */
{
return __libc_res_nsearch(statp, name, class, type, answer,
anslen, NULL, NULL, NULL, NULL);
anslen, NULL, NULL, NULL, NULL, NULL);
}
libresolv_hidden_def (res_nsearch)
@ -539,7 +544,8 @@ __libc_res_nquerydomain(res_state statp,
u_char **answerp,
u_char **answerp2,
int *nanswerp2,
int *resplen2)
int *resplen2,
int *answerp2_malloced)
{
char nbuf[MAXDNAME];
const char *longname = nbuf;
@ -581,7 +587,7 @@ __libc_res_nquerydomain(res_state statp,
}
return (__libc_res_nquery(statp, longname, class, type, answer,
anslen, answerp, answerp2, nanswerp2,
resplen2));
resplen2, answerp2_malloced));
}
int
@ -593,7 +599,8 @@ res_nquerydomain(res_state statp,
int anslen) /* size of answer */
{
return __libc_res_nquerydomain(statp, name, domain, class, type,
answer, anslen, NULL, NULL, NULL, NULL);
answer, anslen, NULL, NULL, NULL, NULL,
NULL);
}
libresolv_hidden_def (res_nquerydomain)

21
resolv/res_send.c
View File

@ -186,12 +186,12 @@ evNowTime(struct timespec *res) {
static int send_vc(res_state, const u_char *, int,
const u_char *, int,
u_char **, int *, int *, int, u_char **,
u_char **, int *, int *);
u_char **, int *, int *, int *);
static int send_dg(res_state, const u_char *, int,
const u_char *, int,
u_char **, int *, int *, int,
int *, int *, u_char **,
u_char **, int *, int *);
u_char **, int *, int *, int *);
#ifdef DEBUG
static void Aerror(const res_state, FILE *, const char *, int,
const struct sockaddr *);
@ -343,7 +343,7 @@ int
__libc_res_nsend(res_state statp, const u_char *buf, int buflen,
const u_char *buf2, int buflen2,
u_char *ans, int anssiz, u_char **ansp, u_char **ansp2,
int *nansp2, int *resplen2)
int *nansp2, int *resplen2, int *ansp2_malloced)
{
int gotsomewhere, terrno, try, v_circuit, resplen, ns, n;
@ -546,7 +546,8 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
try = statp->retry;
n = send_vc(statp, buf, buflen, buf2, buflen2,
&ans, &anssiz, &terrno,
ns, ansp, ansp2, nansp2, resplen2);
ns, ansp, ansp2, nansp2, resplen2,
ansp2_malloced);
if (n < 0)
return (-1);
if (n == 0 && (buf2 == NULL || *resplen2 == 0))
@ -556,7 +557,7 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
n = send_dg(statp, buf, buflen, buf2, buflen2,
&ans, &anssiz, &terrno,
ns, &v_circuit, &gotsomewhere, ansp,
ansp2, nansp2, resplen2);
ansp2, nansp2, resplen2, ansp2_malloced);
if (n < 0)
return (-1);
if (n == 0 && (buf2 == NULL || *resplen2 == 0))
@ -646,7 +647,7 @@ res_nsend(res_state statp,
const u_char *buf, int buflen, u_char *ans, int anssiz)
{
return __libc_res_nsend(statp, buf, buflen, NULL, 0, ans, anssiz,
NULL, NULL, NULL, NULL);
NULL, NULL, NULL, NULL, NULL);
}
libresolv_hidden_def (res_nsend)
@ -657,7 +658,7 @@ send_vc(res_state statp,
const u_char *buf, int buflen, const u_char *buf2, int buflen2,
u_char **ansp, int *anssizp,
int *terrno, int ns, u_char **anscp, u_char **ansp2, int *anssizp2,
int *resplen2)
int *resplen2, int *ansp2_malloced)
{
const HEADER *hp = (HEADER *) buf;
const HEADER *hp2 = (HEADER *) buf2;
@ -823,6 +824,8 @@ send_vc(res_state statp,
}
*thisanssizp = MAXPACKET;
*thisansp = newp;
if (thisansp == ansp2)
*ansp2_malloced = 1;
anhp = (HEADER *) newp;
len = rlen;
} else {
@ -992,7 +995,7 @@ send_dg(res_state statp,
const u_char *buf, int buflen, const u_char *buf2, int buflen2,
u_char **ansp, int *anssizp,
int *terrno, int ns, int *v_circuit, int *gotsomewhere, u_char **anscp,
u_char **ansp2, int *anssizp2, int *resplen2)
u_char **ansp2, int *anssizp2, int *resplen2, int *ansp2_malloced)
{
const HEADER *hp = (HEADER *) buf;
const HEADER *hp2 = (HEADER *) buf2;
@ -1238,6 +1241,8 @@ send_dg(res_state statp,
if (newp != NULL) {
*anssizp = MAXPACKET;
*thisansp = ans = newp;
if (thisansp == ansp2)
*ansp2_malloced = 1;
}
}
HEADER *anhp = (HEADER *) *thisansp;