Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031279AbaGDW1S (ORCPT ); Fri, 4 Jul 2014 18:27:18 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57725 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760802AbaGDWWv (ORCPT ); Fri, 4 Jul 2014 18:22:51 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Beulich , "Don A. Bailey" Subject: [PATCH 3.14 53/59] lz4: add overrun checks to lz4_uncompress_unknownoutputsize() Date: Fri, 4 Jul 2014 15:19:42 -0700 Message-Id: <20140704221542.066435608@linuxfoundation.org> X-Mailer: git-send-email 2.0.1 In-Reply-To: <20140704221539.544876024@linuxfoundation.org> References: <20140704221539.544876024@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Greg Kroah-Hartman commit 4a3a99045177369700c60d074c0e525e8093b0fc upstream. Jan points out that I forgot to make the needed fixes to the lz4_uncompress_unknownoutputsize() function to mirror the changes done in lz4_decompress() with regards to potential pointer overflows. The only in-kernel user of this function is the zram code, which only takes data from a valid compressed buffer that it made itself, so it's not a big issue. But due to external kernel modules using this function, it's better to be safe here. Reported-by: Jan Beulich Cc: "Don A. Bailey" Signed-off-by: Greg Kroah-Hartman --- lib/lz4/lz4_decompress.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/lib/lz4/lz4_decompress.c +++ b/lib/lz4/lz4_decompress.c @@ -192,6 +192,8 @@ static int lz4_uncompress_unknownoutputs int s = 255; while ((ip < iend) && (s == 255)) { s = *ip++; + if (unlikely(length > (size_t)(length + s))) + goto _output_error; length += s; } } @@ -232,6 +234,8 @@ static int lz4_uncompress_unknownoutputs if (length == ML_MASK) { while (ip < iend) { int s = *ip++; + if (unlikely(length > (size_t)(length + s))) + goto _output_error; length += s; if (s == 255) continue; @@ -284,7 +288,7 @@ static int lz4_uncompress_unknownoutputs /* write overflow error detected */ _output_error: - return (int) (-(((char *) ip) - source)); + return -1; } int lz4_decompress(const unsigned char *src, size_t *src_len, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/