From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50498) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WSmbz-0001ui-4Y for qemu-devel@nongnu.org; Wed, 26 Mar 2014 08:07:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WSmbt-00049o-6k for qemu-devel@nongnu.org; Wed, 26 Mar 2014 08:07:15 -0400 From: Stefan Hajnoczi Date: Wed, 26 Mar 2014 13:05:55 +0100 Message-Id: <1395835569-21193-34-git-send-email-stefanha@redhat.com> In-Reply-To: <1395835569-21193-1-git-send-email-stefanha@redhat.com> References: <1395835569-21193-1-git-send-email-stefanha@redhat.com> Subject: [Qemu-devel] [PATCH for-2.0 33/47] dmg: prevent out-of-bounds array access on terminator List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , pmatouse@redhat.com, qemu-stable@nongnu.org, Stefan Hajnoczi When a terminator is reached the base for offsets and sectors is stored. The following records that are processed will use this base value. If the first record we encounter is a terminator, then calculating the base values would result in out-of-bounds array accesses. Don't do that. Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/dmg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/dmg.c b/block/dmg.c index be2f26e..f4f3e8e 100644 --- a/block/dmg.c +++ b/block/dmg.c @@ -182,7 +182,7 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags, offset += 4; if (s->types[i] != 0x80000005 && s->types[i] != 1 && s->types[i] != 2) { - if (s->types[i] == 0xffffffff) { + if (s->types[i] == 0xffffffff && i > 0) { last_in_offset = s->offsets[i - 1] + s->lengths[i - 1]; last_out_offset = s->sectors[i - 1] + s->sectorcounts[i - 1]; -- 1.8.5.3