From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.0 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id C09101F461 for ; Fri, 28 Jun 2019 22:32:47 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:cc:subject:in-reply-to:date:message-id :mime-version:content-type; q=dns; s=default; b=tmHd4wPnRZMeYIEZ aGB/Zqlpsay6vbkz4oXfWsnzr662vqO8Zl5zZHW6+cxYpo5P+S3olpn+OHFtYUUj INHfuSpUg9c9QVZbq88mQn39E8DG3Wio12yT98NTuI2C6y6toXO6nVaBjvC0t1FS lWfi2Xx687Y//Y4xD5aC+Qm5me0= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:cc:subject:in-reply-to:date:message-id :mime-version:content-type; s=default; bh=77X1XkkCAWZeDWSv5sdeiH LsYmg=; b=qaym1rxmkDsUZw1U4hXdwIGJePz90cdXw/Sexe0b0614OwqiX5lpHJ blvTNHw1dkYSxnQTdP0G7jgU0292l5BGNNqteiiOmAev6CGT5TjelZMKmpFMxaUj iWOtrfjnP3CXzDpAqd2/sg1ssYJylsERQneUKtBEz/92GXsVkrHwE= Received: (qmail 82467 invoked by alias); 28 Jun 2019 22:32:44 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 82459 invoked by uid 89); 28 Jun 2019 22:32:44 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: mx1.redhat.com From: DJ Delorie To: Florian Weimer Cc: schwab@suse.de, carlos@redhat.com, libc-alpha@sourceware.org Subject: Re: [PATCHv8] nss_db: protect against empty mappings In-Reply-To: <87ef3domn5.fsf@oldenburg2.str.redhat.com> (message from Florian Weimer on Fri, 28 Jun 2019 15:38:38 +0200) Date: Fri, 28 Jun 2019 18:32:35 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain Florian Weimer writes: >> You could use xasprintf and free the pointer. > > Please also post the planned commit message. Thanks. latest, with xasprintf, and full commit blob posted... >From e465ac6a0cf322c72028d54cc6eb534bb035bd0d Mon Sep 17 00:00:00 2001 From: DJ Delorie Date: Fri, 28 Jun 2019 18:30:00 -0500 Subject: nss_db: fix endent wrt NULL mappings [BZ #24695] [BZ #24696] nss_db allows for getpwent et al to be called without a set*ent, but it only works once. After the last get*ent a set*ent is required to restart, because the end*ent did not properly reset the module. Resetting it to NULL allows for a proper restart. If the database doesn't exist, however, end*ent erroniously called munmap which set errno. The test case runs "makedb" inside the testroot, so needs selinux DSOs installed. diff --git a/ChangeLog b/ChangeLog index aece032385..37be9a998a 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,19 @@ +2019-06-28 DJ Delorie + Sergei Trofimovich + + [BZ #24696] + [BZ #24695] + * nss/nss_db/db-open.c (internal_endent): Protect against NULL + mappings. + * nss/tst-nss-db-endgrent.c: New. + * nss/tst-nss-db-endgrent.root: New. + * nss/tst-nss-db-endpwent.c: New. + * nss/tst-nss-db-endpwent.root: New. + * nss/Makefile: Add new tests. + * support/links-dso-program-c.c: Add selinux dependency. + * support/links-dso-program.cc: Add selinux dependency. + * support/Makefile: Build those with -lselinux if enabled. + 2019-06-28 Wilco Dijkstra * benchtests/bench-math-inlines.c: Increase iterations. diff --git a/nss/Makefile b/nss/Makefile index 95081bddc5..a15c3b7d90 100644 --- a/nss/Makefile +++ b/nss/Makefile @@ -61,7 +61,9 @@ xtests = bug-erange tests-container = \ tst-nss-test3 \ - tst-nss-files-hosts-long + tst-nss-files-hosts-long \ + tst-nss-db-endpwent \ + tst-nss-db-endgrent # Tests which need libdl ifeq (yes,$(build-shared)) diff --git a/nss/nss_db/db-open.c b/nss/nss_db/db-open.c index 8a83d6b930..3fa11e9ab0 100644 --- a/nss/nss_db/db-open.c +++ b/nss/nss_db/db-open.c @@ -63,5 +63,9 @@ internal_setent (const char *file, struct nss_db_map *mapping) void internal_endent (struct nss_db_map *mapping) { - munmap (mapping->header, mapping->len); + if (mapping->header != NULL) + { + munmap (mapping->header, mapping->len); + mapping->header = NULL; + } } diff --git a/nss/tst-nss-db-endgrent.c b/nss/tst-nss-db-endgrent.c new file mode 100644 index 0000000000..367cc6c901 --- /dev/null +++ b/nss/tst-nss-db-endgrent.c @@ -0,0 +1,54 @@ +/* Test for endgrent changing errno for BZ #24696 + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include +#include + +#include +#include + +/* The following test verifies that if the db NSS Service is initialized + with no database (getgrent), that a subsequent closure (endgrent) does + not set errno. In the case of the db service it is not an error to close + the service and so it should not set errno. */ + +static int +do_test (void) +{ + /* Just make sure it's not there, although usually it won't be. */ + unlink ("/var/db/group.db"); + + /* This, in conjunction with the testroot's nsswitch.conf, causes + the nss_db module to be "connected" and initialized - but the + testroot has no group.db, so no mapping will be created. */ + getgrent (); + + errno = 0; + + /* Before the fix, this would call munmap (NULL) and set errno. */ + endgrent (); + + if (errno != 0) + FAIL_EXIT1 ("endgrent set errno to %d\n", errno); + + return 0; +} +#include diff --git a/nss/tst-nss-db-endgrent.root/etc/nsswitch.conf b/nss/tst-nss-db-endgrent.root/etc/nsswitch.conf new file mode 100644 index 0000000000..21471df94f --- /dev/null +++ b/nss/tst-nss-db-endgrent.root/etc/nsswitch.conf @@ -0,0 +1 @@ +group : db files diff --git a/nss/tst-nss-db-endpwent.c b/nss/tst-nss-db-endpwent.c new file mode 100644 index 0000000000..cb85410b7c --- /dev/null +++ b/nss/tst-nss-db-endpwent.c @@ -0,0 +1,66 @@ +/* Test for endpwent->getpwent crash for BZ #24695 + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include + +#include +#include + +/* It is entirely allowed to start with a getpwent call without + resetting the state of the service via a call to setpwent. + You can also call getpwent more times than you have entries in + the service, and it should not fail. This test iteratates the + database once, gets to the end, and then attempts a second + iteration to look for crashes. */ + +static void +try_it (void) +{ + struct passwd *pw; + + /* setpwent is intentionally omitted here. The first call to + getpwent detects that it's first and initializes. The second + time try_it is called, this "first call" was not detected before + the fix, and getpwent would crash. */ + + while ((pw = getpwent ()) != NULL) + ; + + /* We only care if this segfaults or not. */ + endpwent (); +} + +static int +do_test (void) +{ + char *cmd; + + cmd = xasprintf ("%s/makedb -o /var/db/passwd.db /var/db/passwd.in", + support_bindir_prefix); + system (cmd); + free (cmd); + + try_it (); + try_it (); + + return 0; +} +#include diff --git a/nss/tst-nss-db-endpwent.root/etc/nsswitch.conf b/nss/tst-nss-db-endpwent.root/etc/nsswitch.conf new file mode 100644 index 0000000000..593ffc564a --- /dev/null +++ b/nss/tst-nss-db-endpwent.root/etc/nsswitch.conf @@ -0,0 +1 @@ +passwd: db diff --git a/nss/tst-nss-db-endpwent.root/var/db/passwd.in b/nss/tst-nss-db-endpwent.root/var/db/passwd.in new file mode 100644 index 0000000000..98f39126ef --- /dev/null +++ b/nss/tst-nss-db-endpwent.root/var/db/passwd.in @@ -0,0 +1,4 @@ +.root root:x:0:0:root:/root:/bin/bash +=0 root:x:0:0:root:/root:/bin/bash +.bin bin:x:1:1:bin:/bin:/sbin/nologin +=1 bin:x:1:1:bin:/bin:/sbin/nologin diff --git a/support/Makefile b/support/Makefile index 56c1ed43bb..ab66913a02 100644 --- a/support/Makefile +++ b/support/Makefile @@ -191,6 +191,11 @@ LINKS_DSO_PROGRAM = links-dso-program LDLIBS-links-dso-program = -lstdc++ -lgcc -lgcc_s $(libunwind) endif +ifeq (yes,$(have-selinux)) +LDLIBS-$(LINKS_DSO_PROGRAM) += -lselinux +endif + + LDLIBS-test-container = $(libsupport) others += test-container diff --git a/support/links-dso-program-c.c b/support/links-dso-program-c.c index d28a28a0d0..5fcbab2c17 100644 --- a/support/links-dso-program-c.c +++ b/support/links-dso-program-c.c @@ -1,9 +1,26 @@ #include +/* makedb needs selinux dso's. */ +#ifdef HAVE_SELINUX +# include +#endif + +/* The purpose of this file is to indicate to the build system which + shared objects need to be copied into the testroot, such as gcc or + selinux support libraries. This program is never executed, only + scanned for dependencies on shared objects, so the code below may + seem weird - it's written to survive gcc optimization and force + such dependencies. +*/ + int main (int argc, char **argv) { /* Complexity to keep gcc from optimizing this away. */ printf ("This is a test %s.\n", argc > 1 ? argv[1] : "null"); +#ifdef HAVE_SELINUX + /* This exists to force libselinux.so to be required. */ + printf ("selinux %d\n", is_selinux_enabled ()); +#endif return 0; } diff --git a/support/links-dso-program.cc b/support/links-dso-program.cc index dba6976c06..4bc2411086 100644 --- a/support/links-dso-program.cc +++ b/support/links-dso-program.cc @@ -1,11 +1,28 @@ #include +/* makedb needs selinux dso's. */ +#ifdef HAVE_SELINUX +# include +#endif + using namespace std; +/* The purpose of this file is to indicate to the build system which + shared objects need to be copied into the testroot, such as gcc or + selinux support libraries. This program is never executed, only + scanned for dependencies on shared objects, so the code below may + seem weird - it's written to survive gcc optimization and force + such dependencies. +*/ + int main (int argc, char **argv) { /* Complexity to keep gcc from optimizing this away. */ cout << (argc > 1 ? argv[1] : "null"); +#ifdef HAVE_SELINUX + /* This exists to force libselinux.so to be required. */ + cout << "selinux " << is_selinux_enabled (); +#endif return 0; }