From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49890) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YC8xv-0001Wy-GT for qemu-devel@nongnu.org; Fri, 16 Jan 2015 10:37:44 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YC8xp-0000gU-Oz for qemu-devel@nongnu.org; Fri, 16 Jan 2015 10:37:39 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50742) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YC8xp-0000gH-Ir for qemu-devel@nongnu.org; Fri, 16 Jan 2015 10:37:33 -0500 From: Stefan Hajnoczi Date: Fri, 16 Jan 2015 15:37:03 +0000 Message-Id: <1421422633-25536-7-git-send-email-stefanha@redhat.com> In-Reply-To: <1421422633-25536-1-git-send-email-stefanha@redhat.com> References: <1421422633-25536-1-git-send-email-stefanha@redhat.com> Subject: [Qemu-devel] [PULL 06/16] block/dmg: validate chunk size to avoid overflow List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , Peter Wu , Stefan Hajnoczi From: Peter Wu Previously the chunk size was not checked, allowing for a large memory allocation. This patch checks whether the chunks size is within the resource fork length, and whether the resource fork is below the trailer of the dmg file. Signed-off-by: Peter Wu Reviewed-by: John Snow Message-id: 1420566495-13284-6-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi --- block/dmg.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/block/dmg.c b/block/dmg.c index 4f56227..5c2c2c2 100644 --- a/block/dmg.c +++ b/block/dmg.c @@ -317,7 +317,7 @@ static int dmg_read_resource_fork(BlockDriverState *bs, DmgHeaderState *ds, ret = read_uint32(bs, offset, &count); if (ret < 0) { goto fail; - } else if (count == 0) { + } else if (count == 0 || count > info_end - offset) { ret = -EINVAL; goto fail; } @@ -377,6 +377,11 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags, if (ret < 0) { goto fail; } + if (rsrc_fork_offset >= offset || + rsrc_fork_length > offset - rsrc_fork_offset) { + ret = -EINVAL; + goto fail; + } if (rsrc_fork_length != 0) { ret = dmg_read_resource_fork(bs, &ds, rsrc_fork_offset, rsrc_fork_length); -- 2.1.0