From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755611AbbBSBGA (ORCPT ); Wed, 18 Feb 2015 20:06:00 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:35339 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753179AbbBSAdy (ORCPT ); Wed, 18 Feb 2015 19:33:54 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Jan Kara , Kamal Mostafa 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 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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'; -- 1.9.1