From patchwork Fri Apr 8 20:08:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12807181 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69C59C433F5 for ; Fri, 8 Apr 2022 20:09:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B6A416B0075; Fri, 8 Apr 2022 16:09:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B19856B0078; Fri, 8 Apr 2022 16:09:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A092F6B007B; Fri, 8 Apr 2022 16:09:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0251.hostedemail.com [216.40.44.251]) by kanga.kvack.org (Postfix) with ESMTP id 92B276B0075 for ; Fri, 8 Apr 2022 16:09:01 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 493B0183CB077 for ; Fri, 8 Apr 2022 20:09:01 +0000 (UTC) X-FDA: 79334800482.25.EA4B9D2 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf11.hostedemail.com (Postfix) with ESMTP id CF91440002 for ; Fri, 8 Apr 2022 20:09:00 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2BFC861E28; Fri, 8 Apr 2022 20:09:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 80FFFC385A6; Fri, 8 Apr 2022 20:08:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1649448539; bh=5no2esH8/58mNWM6tktmP1+A/Rk1YVrxTuyDg3i895M=; h=Date:To:From:In-Reply-To:Subject:From; b=wPFVz06gIltEbF4SwvZPdcxkjMSNpicE1XOusXECnALO1GCNQDvkljk8qVDtDkvO4 sVXkvFb9/G/7BoD23GDUxEz4BW5eqpeuRRXtCqW1n7/7yz3jj/NdLcXR9pdbc1jwh1 Va1HCDbksZFeSRGgr3PriZZWmRDw/mIS6J9Zz6wU= Date: Fri, 08 Apr 2022 13:08:58 -0700 To: terrelln@fb.com,stable@vger.kernel.org,hsiangkao@linux.alibaba.com,cy.fan@huawei.com,cyan@fb.com,guoxuenan@huawei.com,akpm@linux-foundation.org,patches@lists.linux.dev,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220408130819.a89195e527ce58dfbe0700b9@linux-foundation.org> Subject: [patch 3/9] lz4: fix LZ4_decompress_safe_partial read out of bound Message-Id: <20220408200859.80FFFC385A6@smtp.kernel.org> X-Rspamd-Server: rspam09 X-Rspam-User: X-Stat-Signature: 8dtqejwwa7fkii3qpzgqazzdburr857q Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=wPFVz06g; dmarc=none; spf=pass (imf11.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspamd-Queue-Id: CF91440002 X-HE-Tag: 1649448540-692423 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Guo Xuenan Subject: lz4: fix LZ4_decompress_safe_partial read out of bound When partialDecoding, it is EOF if we've either filled the output buffer or can't proceed with reading an offset for following match. In some extreme corner cases when compressed data is suitably corrupted, UAF will occur. As reported by KASAN [1], LZ4_decompress_safe_partial may lead to read out of bound problem during decoding. lz4 upstream has fixed it [2] and this issue has been disscussed here [3] before. current decompression routine was ported from lz4 v1.8.3, bumping lib/lz4 to v1.9.+ is certainly a huge work to be done later, so, we'd better fix it first. [1] https://lore.kernel.org/all/000000000000830d1205cf7f0477@google.com/ [2] https://github.com/lz4/lz4/commit/c5d6f8a8be3927c0bec91bcc58667a6cfad244ad# [3] https://lore.kernel.org/all/CC666AE8-4CA4-4951-B6FB-A2EFDE3AC03B@fb.com/ Link: https://lkml.kernel.org/r/20211111105048.2006070-1-guoxuenan@huawei.com Reported-by: syzbot+63d688f1d899c588fb71@syzkaller.appspotmail.com Signed-off-by: Guo Xuenan Reviewed-by: Nick Terrell Acked-by: Gao Xiang Cc: Yann Collet Cc: Chengyang Fan Cc: Signed-off-by: Andrew Morton --- lib/lz4/lz4_decompress.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/lib/lz4/lz4_decompress.c~lz4-fix-lz4_decompress_safe_partial-read-out-of-bound +++ a/lib/lz4/lz4_decompress.c @@ -271,8 +271,12 @@ static FORCE_INLINE int LZ4_decompress_g ip += length; op += length; - /* Necessarily EOF, due to parsing restrictions */ - if (!partialDecoding || (cpy == oend)) + /* Necessarily EOF when !partialDecoding. + * When partialDecoding, it is EOF if we've either + * filled the output buffer or + * can't proceed with reading an offset for following match. + */ + if (!partialDecoding || (cpy == oend) || (ip >= (iend - 2))) break; } else { /* may overwrite up to WILDCOPYLENGTH beyond cpy */