Sourceware bug 16574
commit d668061994a7486a3ba9c7d5e7882d85a2883707
Author: Andreas Schwab <schwab@suse.de>
Date: Thu Feb 13 11:01:57 2014 +0100
Fix memory leak in _nss_dns_gethostbyname4_r with big DNS answer
commit ab7ac0f2cf8731fe4c3f3aea6088a7c0127b5725
Author: Ondřej Bílka <neleai@seznam.cz>
Date: Sun Feb 16 12:59:23 2014 +0100
Deduplicate resolv/nss_dns/dns-host.c
In resolv/nss_dns/dns-host.c one of code path duplicated code after
that. We merge these paths.
commit ab09bf616ad527b249aca5f2a4956fd526f0712f
Author: Andreas Schwab <schwab@suse.de>
Date: Tue Feb 18 10:57:25 2014 +0100
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
Index: glibc-2.17-c758a686/include/resolv.h
===================================================================
--- glibc-2.17-c758a686.orig/include/resolv.h
+++ glibc-2.17-c758a686/include/resolv.h
@@ -56,11 +56,11 @@ 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)
Index: glibc-2.17-c758a686/resolv/gethnamaddr.c
===================================================================
--- glibc-2.17-c758a686.orig/resolv/gethnamaddr.c
+++ glibc-2.17-c758a686/resolv/gethnamaddr.c
@@ -616,7 +616,7 @@ 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);
@@ -711,12 +711,12 @@ 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)
Index: glibc-2.17-c758a686/resolv/nss_dns/dns-canon.c
===================================================================
--- glibc-2.17-c758a686.orig/resolv/nss_dns/dns-canon.c
+++ glibc-2.17-c758a686/resolv/nss_dns/dns-canon.c
@@ -61,7 +61,7 @@ _nss_dns_getcanonname_r (const char *nam
{
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.
Index: glibc-2.17-c758a686/resolv/nss_dns/dns-host.c
===================================================================
--- glibc-2.17-c758a686.orig/resolv/nss_dns/dns-host.c
+++ glibc-2.17-c758a686/resolv/nss_dns/dns-host.c
@@ -190,7 +190,7 @@ _nss_dns_gethostbyname3_r (const char *n
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 *n
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)
{
@@ -308,13 +308,20 @@ _nss_dns_gethostbyname4_r (const char *n
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, 2048, &host_buffer.ptr,
- &ans2p, &nans2p, &resplen2);
- if (n < 0)
+ &ans2p, &nans2p, &resplen2, &ans2p_malloced);
+ if (n >= 0)
+ {
+ status = gaih_getanswer (host_buffer.buf, n, (const querybuf *) ans2p,
+ resplen2, name, pat, buffer, buflen,
+ errnop, herrnop, ttlp);
+ }
+ else
{
switch (errno)
{
@@ -341,16 +348,11 @@ _nss_dns_gethostbyname4_r (const char *n
*errnop = EAGAIN;
else
__set_errno (olderr);
-
- if (host_buffer.buf != orig_host_buffer)
- free (host_buffer.buf);
-
- return status;
}
- status = gaih_getanswer(host_buffer.buf, n, (const querybuf *) ans2p,
- resplen2, name, pat, buffer, buflen,
- errnop, herrnop, ttlp);
+ /* Check whether ans2p was separately allocated. */
+ if (ans2p_malloced)
+ free (ans2p);
if (host_buffer.buf != orig_host_buffer)
free (host_buffer.buf);
@@ -460,7 +462,7 @@ _nss_dns_gethostbyaddr2_r (const void *a
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;
}
@@ -481,14 +483,14 @@ _nss_dns_gethostbyaddr2_r (const void *a
}
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)
{
Index: glibc-2.17-c758a686/resolv/nss_dns/dns-network.c
===================================================================
--- glibc-2.17-c758a686.orig/resolv/nss_dns/dns-network.c
+++ glibc-2.17-c758a686/resolv/nss_dns/dns-network.c
@@ -129,7 +129,7 @@ _nss_dns_getnetbyname_r (const char *nam
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, i
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. */
Index: glibc-2.17-c758a686/resolv/res_query.c
===================================================================
--- glibc-2.17-c758a686.orig/resolv/res_query.c
+++ glibc-2.17-c758a686/resolv/res_query.c
@@ -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
/* If the second response is valid then we use that. */
|| (ret == 0 && resplen2 != NULL && *resplen2 > 0))
@@ -388,11 +392,11 @@ __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;
}
}
@@ -419,7 +423,7 @@ __libc_res_nsearch(res_state statp,
class, type,
answer, anslen, answerp,
answerp2, nanswerp2,
- resplen2);
+ resplen2, answerp2_malloced);
if (ret > 0 || (ret == 0 && resplen2 != NULL
&& *resplen2 > 0))
return (ret);
@@ -428,12 +432,11 @@ __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;
}
/*
@@ -489,7 +492,8 @@ __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 || (ret == 0 && resplen2 != NULL
&& *resplen2 > 0))
return (ret);
@@ -502,10 +506,11 @@ __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);
@@ -525,7 +530,7 @@ 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)
@@ -543,7 +548,8 @@ __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;
@@ -585,7 +591,7 @@ __libc_res_nquerydomain(res_state statp,
}
return (__libc_res_nquery(statp, longname, class, type, answer,
anslen, answerp, answerp2, nanswerp2,
- resplen2));
+ resplen2, answerp2_malloced));
}
int
@@ -597,7 +603,8 @@ 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)
Index: glibc-2.17-c758a686/resolv/res_send.c
===================================================================
--- glibc-2.17-c758a686.orig/resolv/res_send.c
+++ glibc-2.17-c758a686/resolv/res_send.c
@@ -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
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
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;
@@ -1235,6 +1238,8 @@ send_dg(res_state statp,
if (newp != NULL) {
*anssizp = MAXPACKET;
*thisansp = ans = newp;
+ if (thisansp == ansp2)
+ *ansp2_malloced = 1;
}
}
HEADER *anhp = (HEADER *) *thisansp;