From patchwork Thu Apr 14 13:13:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 562223 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A12AC433F5 for ; Thu, 14 Apr 2022 14:12:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344173AbiDNONg (ORCPT ); Thu, 14 Apr 2022 10:13:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347643AbiDNN7Y (ORCPT ); Thu, 14 Apr 2022 09:59:24 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C63A546154; Thu, 14 Apr 2022 06:50:47 -0700 (PDT) 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 F0FB961D29; Thu, 14 Apr 2022 13:50:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D9913C385A1; Thu, 14 Apr 2022 13:50:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649944246; bh=u2eSWplhryUg880omtp8DMLc1eKdaByhY5LAUhuhCZo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YQGFlLyDHcx3WMZgcWjGtFRWZVyhsGxtihgYUGEM4JMgtnqThSfh1zC4y5IqxFe80 Vy+cT8O5U6b1oVrufM/W8Y09OmIOcfCF0slgyhwt8Jwsrc3iqiXLEyGEtJnpGtzZY+ rVgQFHeZ52CJj+B2MUsIaQzAR70byOCAmdUgqxA0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+63d688f1d899c588fb71@syzkaller.appspotmail.com, Guo Xuenan , Nick Terrell , Gao Xiang , Yann Collet , Chengyang Fan , Andrew Morton , Linus Torvalds Subject: [PATCH 5.4 447/475] lz4: fix LZ4_decompress_safe_partial read out of bound Date: Thu, 14 Apr 2022 15:13:52 +0200 Message-Id: <20220414110907.568465674@linuxfoundation.org> X-Mailer: git-send-email 2.35.2 In-Reply-To: <20220414110855.141582785@linuxfoundation.org> References: <20220414110855.141582785@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Guo Xuenan commit eafc0a02391b7b36617b36c97c4b5d6832cf5e24 upstream. 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 Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- lib/lz4/lz4_decompress.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/lib/lz4/lz4_decompress.c +++ b/lib/lz4/lz4_decompress.c @@ -268,8 +268,12 @@ 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 */