From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 93510 invoked by alias); 25 Jun 2018 17:49:42 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 93291 invoked by uid 89); 25 Jun 2018 17:49:37 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,KAM_SHORT,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mx1.redhat.com Date: Mon, 25 Jun 2018 17:49:00 -0000 To: libc-alpha@sourceware.org Subject: [PATCH] _nss_nis_initgroups_dyn: Use struct scratch_buffer [BZ #18023] User-Agent: Heirloom mailx 12.5 7/5/10 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <20180625174931.9C2C743994575@oldenburg.str.redhat.com> From: fweimer@redhat.com (Florian Weimer) X-SW-Source: 2018-06/txt/msg00749.txt.bz2 Remove extend_alloca usage. Also adjusts the internal function get_uid. 2018-06-25 Florian Weimer [BZ #18023] * nis/nss_nis/nis-initgroups.c (get_uid, _nss_nis_initgroups_dyn): Use struct scratch_buffer instead of extend_alloca. diff --git a/nis/nss_nis/nis-initgroups.c b/nis/nss_nis/nis-initgroups.c index a47b4d7ada..ca043d4e5a 100644 --- a/nis/nss_nis/nis-initgroups.c +++ b/nis/nss_nis/nis-initgroups.c @@ -16,7 +16,6 @@ License along with the GNU C Library; if not, see . */ -#include #include #include #include @@ -27,6 +26,7 @@ #include #include #include +#include #include "nss-nis.h" #include @@ -120,27 +120,30 @@ internal_getgrent_r (struct group *grp, char *buffer, size_t buflen, static int get_uid (const char *user, uid_t *uidp) { - size_t buflen = sysconf (_SC_GETPW_R_SIZE_MAX); - char *buf = (char *) alloca (buflen); + struct scratch_buffer tmpbuf; + scratch_buffer_init (&tmpbuf); while (1) { struct passwd result; struct passwd *resp; - int r = getpwnam_r (user, &result, buf, buflen, &resp); + int r = getpwnam_r (user, &result, tmpbuf.data, tmpbuf.length, &resp); if (r == 0 && resp != NULL) { *uidp = resp->pw_uid; + scratch_buffer_free (&tmpbuf); return 0; } if (r != ERANGE) break; - buf = extend_alloca (buf, buflen, 2 * buflen); + if (!scratch_buffer_grow (&tmpbuf)) + return 1; } + scratch_buffer_free (&tmpbuf); return 1; } @@ -254,8 +257,6 @@ _nss_nis_initgroups_dyn (const char *user, gid_t group, long int *start, } struct group grpbuf, *g; - size_t buflen = sysconf (_SC_GETPW_R_SIZE_MAX); - char *tmpbuf; enum nss_status status; intern_t intern = { NULL, NULL, 0 }; gid_t *groups = *groupsp; @@ -264,15 +265,20 @@ _nss_nis_initgroups_dyn (const char *user, gid_t group, long int *start, if (status != NSS_STATUS_SUCCESS) return status; - tmpbuf = __alloca (buflen); + struct scratch_buffer tmpbuf; + scratch_buffer_init (&tmpbuf); while (1) { while ((status = - internal_getgrent_r (&grpbuf, tmpbuf, buflen, errnop, + internal_getgrent_r (&grpbuf, tmpbuf.data, tmpbuf.length, errnop, &intern)) == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) - tmpbuf = extend_alloca (tmpbuf, buflen, 2 * buflen); + if (!scratch_buffer_grow (&tmpbuf)) + { + status = NSS_STATUS_TRYAGAIN; + goto done; + } if (status != NSS_STATUS_SUCCESS) { @@ -331,6 +337,7 @@ done: intern.start = intern.start->next; free (intern.next); } + scratch_buffer_free (&tmpbuf); return status; }