From patchwork Wed Dec 8 17:02:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Wielaard X-Patchwork-Id: 48642 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 28566385843B for ; Wed, 8 Dec 2021 17:02:57 +0000 (GMT) X-Original-To: elfutils-devel@sourceware.org Delivered-To: elfutils-devel@sourceware.org Received: from gnu.wildebeest.org (gnu.wildebeest.org [45.83.234.184]) by sourceware.org (Postfix) with ESMTPS id 7B5E73858413 for ; Wed, 8 Dec 2021 17:02:50 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 7B5E73858413 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=klomp.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=klomp.org Received: from tarox.wildebeest.org (83-87-18-245.cable.dynamic.v4.ziggo.nl [83.87.18.245]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by gnu.wildebeest.org (Postfix) with ESMTPSA id D93713000ED0; Wed, 8 Dec 2021 18:02:48 +0100 (CET) Received: by tarox.wildebeest.org (Postfix, from userid 1000) id 96466413CC9A; Wed, 8 Dec 2021 18:02:48 +0100 (CET) From: Mark Wielaard To: elfutils-devel@sourceware.org Subject: [PATCH] libdwfl: Add overflow check while iterating in dwfl_segment_report_module Date: Wed, 8 Dec 2021 18:02:27 +0100 Message-Id: <20211208170227.18011-1-mark@klomp.org> X-Mailer: git-send-email 2.18.4 X-Spam-Status: No, score=-9.9 required=5.0 tests=BAYES_00, GIT_PATCH_0, JMQ_SPF_NEUTRAL, KAM_DMARC_STATUS, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: elfutils-devel@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Elfutils-devel mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , Cc: Mark Wielaard Errors-To: elfutils-devel-bounces+patchwork=sourceware.org@sourceware.org Sender: "Elfutils-devel" While iterating the notes we could overflow the len variable if the note name or description was too big. Fix this by adding an (unsigned) overflow check. https://sourceware.org/bugzilla/show_bug.cgi?id=28654 Signed-off-by: Mark Wielaard --- libdwfl/ChangeLog | 5 +++++ libdwfl/dwfl_segment_report_module.c | 6 +++++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog index 520405c8..e1cd70fa 100644 --- a/libdwfl/ChangeLog +++ b/libdwfl/ChangeLog @@ -1,3 +1,8 @@ +2021-12-08 Mark Wielaard + + * dwfl_segment_report_module.c (dwfl_segment_report_module): Add + len overflow check while iterating notes. + 2021-12-08 Mark Wielaard * dwfl_segment_report_module.c (dwfl_segment_report_module): Don't diff --git a/libdwfl/dwfl_segment_report_module.c b/libdwfl/dwfl_segment_report_module.c index f6a1799e..574f02a7 100644 --- a/libdwfl/dwfl_segment_report_module.c +++ b/libdwfl/dwfl_segment_report_module.c @@ -543,10 +543,12 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, const GElf_Nhdr *nh = notes; size_t len = 0; + size_t last_len; while (filesz > len + sizeof (*nh)) { const void *note_name; const void *note_desc; + last_len = len; len += sizeof (*nh); note_name = notes + len; @@ -555,7 +557,9 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, len = align == 8 ? NOTE_ALIGN8 (len) : NOTE_ALIGN4 (len); note_desc = notes + len; - if (unlikely (filesz < len + nh->n_descsz)) + if (unlikely (filesz < len + nh->n_descsz + || len < last_len + || len + nh->n_descsz < last_len)) break; if (nh->n_type == NT_GNU_BUILD_ID