From 052a6ae979f2d93b0382fb8b82be8e0c870a19ba Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 25 Mar 2014 11:45:56 +0100 Subject: [PATCH 38/48] dmg: prevent out-of-bounds array access on terminator RH-Author: Kevin Wolf Message-id: <1395744364-16049-38-git-send-email-kwolf@redhat.com> Patchwork-id: n/a O-Subject: [EMBARGOED RHEL-6.6/6.5.z qemu-kvm PATCH v2 37/45] dmg: prevent out-of-bounds array access on terminator Bugzilla: 1079518 RH-Acked-by: Max Reitz RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Laszlo Ersek Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1079518 Upstream status: Series embargoed 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 files changed, 1 insertions(+), 1 deletions(-) diff --git a/block/dmg.c b/block/dmg.c index 2710faf..0559bbc 100644 --- a/block/dmg.c +++ b/block/dmg.c @@ -174,7 +174,7 @@ static int dmg_open(BlockDriverState *bs, 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]; -- 1.7.1