From patchwork Thu Feb 19 00:31:40 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 441423 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id C33021400DE; Thu, 19 Feb 2015 11:35:38 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1YOF5b-0007TE-8s; Thu, 19 Feb 2015 00:35:35 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1YOF3w-0005yi-KC for kernel-team@lists.ubuntu.com; Thu, 19 Feb 2015 00:33:52 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1YOF3w-0004RV-DM; Thu, 19 Feb 2015 00:33:52 +0000 Received: from kamal by fourier with local (Exim 4.82) (envelope-from ) id 1YOF3t-0004jK-Vr; Wed, 18 Feb 2015 16:33:49 -0800 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 3.13.y-ckt 013/103] udf: Check component length before reading it Date: Wed, 18 Feb 2015 16:31:40 -0800 Message-Id: <1424305990-17983-14-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1424305990-17983-1-git-send-email-kamal@canonical.com> References: <1424305990-17983-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Cc: Kamal Mostafa , Jan Kara X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.13.11-ckt16 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kara commit e237ec37ec154564f8690c5bd1795339955eeef9 upstream. Check that length specified in a component of a symlink fits in the input buffer we are reading. Also properly ignore component length for component types that do not use it. Otherwise we read memory after end of buffer for corrupted udf image. Reported-by: Carl Henrik Lunde Signed-off-by: Jan Kara Signed-off-by: Kamal Mostafa --- fs/udf/symlink.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/udf/symlink.c b/fs/udf/symlink.c index 2d0c372..0422b7b 100644 --- a/fs/udf/symlink.c +++ b/fs/udf/symlink.c @@ -42,14 +42,17 @@ static int udf_pc_to_char(struct super_block *sb, unsigned char *from, tolen--; while (elen < fromlen) { pc = (struct pathComponent *)(from + elen); + elen += sizeof(struct pathComponent); switch (pc->componentType) { case 1: /* * Symlink points to some place which should be agreed * upon between originator and receiver of the media. Ignore. */ - if (pc->lengthComponentIdent > 0) + if (pc->lengthComponentIdent > 0) { + elen += pc->lengthComponentIdent; break; + } /* Fall through */ case 2: if (tolen == 0) @@ -74,6 +77,9 @@ static int udf_pc_to_char(struct super_block *sb, unsigned char *from, /* that would be . - just ignore */ break; case 5: + elen += pc->lengthComponentIdent; + if (elen > fromlen) + return -EIO; comp_len = udf_get_filename(sb, pc->componentIdent, pc->lengthComponentIdent, p, tolen); @@ -85,7 +91,6 @@ static int udf_pc_to_char(struct super_block *sb, unsigned char *from, tolen--; break; } - elen += sizeof(struct pathComponent) + pc->lengthComponentIdent; } if (p > to + 1) p[-1] = '\0';