From: Stefan Hajnoczi Date: Wed, 26 Mar 2014 13:05:55 +0100 Subject: [PATCH] dmg: prevent out-of-bounds array access on terminator 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 Reviewed-by: Max Reitz Signed-off-by: Stefan Hajnoczi (cherry picked from commit 73ed27ec28a1dbebdd2ae792284151f029950fbe) --- block/dmg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/dmg.c b/block/dmg.c index e8b88dc..cb4060c 100644 --- a/block/dmg.c +++ b/block/dmg.c @@ -181,7 +181,7 @@ 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];