Sourceware bug 16574 commit d668061994a7486a3ba9c7d5e7882d85a2883707 Author: Andreas Schwab 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 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 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;