From mboxrd@z Thu Jan 1 00:00:00 1970 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 1EC31C3525B for ; Tue, 12 Apr 2022 07:16:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235391AbiDLHTF (ORCPT ); Tue, 12 Apr 2022 03:19:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57498 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351642AbiDLHMq (ORCPT ); Tue, 12 Apr 2022 03:12:46 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D71C28E3D; Mon, 11 Apr 2022 23:50:54 -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 ams.source.kernel.org (Postfix) with ESMTPS id 4F323B81B43; Tue, 12 Apr 2022 06:50:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91CF6C385A6; Tue, 12 Apr 2022 06:50:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649746252; bh=r7zwxBmSBYLoVuMUOCzhurkmYQox+oscdpkyavZfQGg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NFb8Y9tgG4Dylb0+2rEzyvmD+9rylPFDTUPil+FrcFNd9wU/kyI4F7mJm5X8OEbPL 63HRjebR87jSBM+T2Sdgj3JcgqLBen6W19QqkA5bINnIPYWhpmgxAE6KouwEKdyK6Z qA6vFTCBaL6nKWQrLfNRZ3SP/Dlq3pxK/W5tZDLA= 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 5.15 214/277] lz4: fix LZ4_decompress_safe_partial read out of bound Date: Tue, 12 Apr 2022 08:30:17 +0200 Message-Id: <20220412062948.233488492@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220412062942.022903016@linuxfoundation.org> References: <20220412062942.022903016@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 @@ -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 */