From patchwork Fri Aug 26 12:45:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 57098 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 10C963856278 for ; Fri, 26 Aug 2022 12:46:04 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 10C963856278 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1661517964; bh=qrEjOdHhPOwyge052llbLxFappsRqpalUQkGdPjgA1E=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=GfoSDo3PlNcdxIApeEX5KH+a+g4lKQwaYbva2vcwUpLBMJFyITBWqV9R5gFd6PiVz kCg3+3fcluL+i2G6ahiyQ2owqrJhuwfcZXbYlannR9owgvXO7nVbsosig6vSHPJGGY lgHk04tvupmMrixFlRV9S3E+ZViwDba3qPpYSqTk= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 3F9973858C74 for ; Fri, 26 Aug 2022 12:45:41 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3F9973858C74 Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-356-mIiiJ7U1MYWT1q8Wsu5fiw-1; Fri, 26 Aug 2022 08:45:39 -0400 X-MC-Unique: mIiiJ7U1MYWT1q8Wsu5fiw-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 691DC8582A8 for ; Fri, 26 Aug 2022 12:45:37 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.192.82]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8F960492C3B for ; Fri, 26 Aug 2022 12:45:36 +0000 (UTC) To: libc-alpha@sourceware.org Subject: [PATCH] elf: Call __libc_early_init for reused namespaces (bug 29528) Date: Fri, 26 Aug 2022 14:45:34 +0200 Message-ID: <87v8qfp40h.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.85 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-10.7 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Florian Weimer via Libc-alpha From: Florian Weimer Reply-To: Florian Weimer Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" libc_map is never reset to NULL, neither during dlclose nor on a dlopen call which reuses the namespace structure. As a result, if a namespace is reused, its libc is not initialized properly. The most visible result is a crash in the functions. To prevent similar bugs on namespace reuse from surfacing, unconditionally initialize the chosen namespace to zero using memset. Tested on i686-linux-gnu and x86_64-linux-gnu. Built with build-many-glibcs.py. --- elf/Makefile | 7 +++++++ elf/dl-open.c | 13 +++++++----- elf/tst-dlmopen-twice-mod1.c | 37 ++++++++++++++++++++++++++++++++ elf/tst-dlmopen-twice-mod2.c | 50 ++++++++++++++++++++++++++++++++++++++++++++ elf/tst-dlmopen-twice.c | 34 ++++++++++++++++++++++++++++++ 5 files changed, 136 insertions(+), 5 deletions(-) base-commit: 5ecc98241229d494aaad23a4a3fe106fe11e1f40 diff --git a/elf/Makefile b/elf/Makefile index 3928a08787..008770bfaf 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -410,6 +410,7 @@ tests += \ tst-dlmopen4 \ tst-dlmopen-dlerror \ tst-dlmopen-gethostbyname \ + tst-dlmopen-twice \ tst-dlopenfail \ tst-dlopenfail-2 \ tst-dlopenrpath \ @@ -839,6 +840,8 @@ modules-names += \ tst-dlmopen1mod \ tst-dlmopen-dlerror-mod \ tst-dlmopen-gethostbyname-mod \ + tst-dlmopen-twice-mod1 \ + tst-dlmopen-twice-mod2 \ tst-dlopenfaillinkmod \ tst-dlopenfailmod1 \ tst-dlopenfailmod2 \ @@ -2976,3 +2979,7 @@ $(objpfx)tst-audit-tlsdesc.out: $(objpfx)tst-auditmod-tlsdesc.so tst-audit-tlsdesc-ENV = LD_AUDIT=$(objpfx)tst-auditmod-tlsdesc.so $(objpfx)tst-audit-tlsdesc-dlopen.out: $(objpfx)tst-auditmod-tlsdesc.so tst-audit-tlsdesc-dlopen-ENV = LD_AUDIT=$(objpfx)tst-auditmod-tlsdesc.so + +$(objpfx)tst-dlmopen-twice.out: \ + $(objpfx)tst-dlmopen-twice-mod1.so \ + $(objpfx)tst-dlmopen-twice-mod2.so diff --git a/elf/dl-open.c b/elf/dl-open.c index a23e65926b..46e8066fd8 100644 --- a/elf/dl-open.c +++ b/elf/dl-open.c @@ -844,11 +844,14 @@ _dl_open (const char *file, int mode, const void *caller_dlopen, Lmid_t nsid, _dl_signal_error (EINVAL, file, NULL, N_("\ no more namespaces available for dlmopen()")); } - else if (nsid == GL(dl_nns)) - { - __rtld_lock_initialize (GL(dl_ns)[nsid]._ns_unique_sym_table.lock); - ++GL(dl_nns); - } + + if (nsid == GL(dl_nns)) + ++GL(dl_nns); + + /* Initialize the new namespace. Most members are + zero-initialized, only the lock needs special treatment. */ + memset (&GL(dl_ns)[nsid], 0, sizeof (GL(dl_ns)[nsid])); + __rtld_lock_initialize (GL(dl_ns)[nsid]._ns_unique_sym_table.lock); _dl_debug_update (nsid)->r_state = RT_CONSISTENT; } diff --git a/elf/tst-dlmopen-twice-mod1.c b/elf/tst-dlmopen-twice-mod1.c new file mode 100644 index 0000000000..38a3a5f0ac --- /dev/null +++ b/elf/tst-dlmopen-twice-mod1.c @@ -0,0 +1,37 @@ +/* Initialization of libc after dlmopen/dlclose/dlmopen (bug 29528). Module 1. + Copyright (C) 2022 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 + +static void __attribute__ ((constructor)) +init (void) +{ + puts ("info: tst-dlmopen-twice-mod2.so loaded"); + fflush (stdout); +} + +static void __attribute__ ((destructor)) +fini (void) +{ + puts ("info: tst-dlmopen-twice-mod2.so about to be unloaded"); + fflush (stdout); +} + +/* Large allocation. The second module does not have this, so it + should load libc at a different address. */ +char large_allocate[16 * 1024 * 1024]; diff --git a/elf/tst-dlmopen-twice-mod2.c b/elf/tst-dlmopen-twice-mod2.c new file mode 100644 index 0000000000..40c6c01f96 --- /dev/null +++ b/elf/tst-dlmopen-twice-mod2.c @@ -0,0 +1,50 @@ +/* Initialization of libc after dlmopen/dlclose/dlmopen (bug 29528). Module 2. + Copyright (C) 2022 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 + +static void __attribute__ ((constructor)) +init (void) +{ + puts ("info: tst-dlmopen-twice-mod2.so loaded"); + fflush (stdout); +} + +static void __attribute__ ((destructor)) +fini (void) +{ + puts ("info: tst-dlmopen-twice-mod2.so about to be unloaded"); + fflush (stdout); +} + +int +run_check (void) +{ + puts ("info: about to call isalpha"); + fflush (stdout); + + volatile char ch = 'a'; + if (!isalpha (ch)) + { + puts ("error: isalpha ('a') is not true"); + fflush (stdout); + return 1; + } + return 0; +} diff --git a/elf/tst-dlmopen-twice.c b/elf/tst-dlmopen-twice.c new file mode 100644 index 0000000000..449f3c8fa9 --- /dev/null +++ b/elf/tst-dlmopen-twice.c @@ -0,0 +1,34 @@ +/* Initialization of libc after dlmopen/dlclose/dlmopen (bug 29528). Main. + Copyright (C) 2022 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 + +static int +do_test (void) +{ + void *handle = xdlmopen (LM_ID_NEWLM, "tst-dlmopen-twice-mod1.so", RTLD_NOW); + xdlclose (handle); + handle = xdlmopen (LM_ID_NEWLM, "tst-dlmopen-twice-mod2.so", RTLD_NOW); + int (*run_check) (void) = xdlsym (handle, "run_check"); + TEST_COMPARE (run_check (), 0); + xdlclose (handle); + return 0; +} + +#include