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authorStefan Hajnoczi <stefanha@redhat.com>2014-03-26 13:05:55 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2014-04-01 15:22:35 +0200
commit73ed27ec28a1dbebdd2ae792284151f029950fbe (patch)
tree9b35d05f937d38cbd85e1d4fd3a4d707f988da88
parent2c1885adcf0312da80c7317b09f9adad97fa0fc6 (diff)
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 <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-rw-r--r--block/dmg.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/block/dmg.c b/block/dmg.c
index be2f26e85e..f4f3e8e9f2 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];