From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTP id AD3A63857818 for ; Wed, 23 Jun 2021 12:42:22 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org AD3A63857818 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-452-df63qdUVMA2mnVQqC3zOjg-1; Wed, 23 Jun 2021 08:42:20 -0400 X-MC-Unique: df63qdUVMA2mnVQqC3zOjg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C26C4100A456 for ; Wed, 23 Jun 2021 12:42:19 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-112-211.ams2.redhat.com [10.36.112.211]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 26A4C1036D06 for ; Wed, 23 Jun 2021 12:42:18 +0000 (UTC) From: Florian Weimer To: libc-alpha@sourceware.org Subject: [PATCH] elf: Assert range of ns argument in _dl_debug_initialize Date: Wed, 23 Jun 2021 14:42:17 +0200 Message-ID: <87y2b04us6.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 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-12.7 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_LOW, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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-List-Received-Date: Wed, 23 Jun 2021 12:42:23 -0000 This does not fix any bugs as such, but makes it more obvious if _dl_debug_initialize is called with invalid arguments (which would otherwise cause the function to clobber unrelated data). Tested on i686-linux-gnu and x86_64-linux-gnu. --- elf/dl-debug.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/elf/dl-debug.c b/elf/dl-debug.c index 2cd5f09753..85b087455e 100644 --- a/elf/dl-debug.c +++ b/elf/dl-debug.c @@ -16,6 +16,8 @@ License along with the GNU C Library; if not, see . */ +#include +#include #include @@ -49,7 +51,11 @@ _dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns) if (ns == LM_ID_BASE) r = &_r_debug; else - r = &GL(dl_ns)[ns]._ns_debug; + { + assert (ns >= 0); + assert (ns < array_length (GL (dl_ns))); + r = &GL(dl_ns)[ns]._ns_debug; + } if (r->r_map == NULL || ldbase != 0) {