block/dmg: validate chunk size to avoid overflow
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 <peter@lekensteyn.nl> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 1420566495-13284-6-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
parent
7aee37b93a
commit
f6e6652d7c
@ -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);
|
||||
|
Loading…
Reference in New Issue
Block a user