ssi-sd: fix buffer overrun on invalid state load

CVE-2013-4537

s->arglen is taken from wire and used as idx
in ssi_sd_transfer().

Validate it before access.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2014-04-28 16:08:14 +03:00 committed by Juan Quintela
parent 767adce2d9
commit a9c380db3b

View File

@ -230,8 +230,17 @@ static int ssi_sd_load(QEMUFile *f, void *opaque, int version_id)
for (i = 0; i < 5; i++)
s->response[i] = qemu_get_be32(f);
s->arglen = qemu_get_be32(f);
if (s->mode == SSI_SD_CMDARG &&
(s->arglen < 0 || s->arglen >= ARRAY_SIZE(s->cmdarg))) {
return -EINVAL;
}
s->response_pos = qemu_get_be32(f);
s->stopping = qemu_get_be32(f);
if (s->mode == SSI_SD_RESPONSE &&
(s->response_pos < 0 || s->response_pos >= ARRAY_SIZE(s->response) ||
(!s->stopping && s->arglen > ARRAY_SIZE(s->response)))) {
return -EINVAL;
}
ss->cs = qemu_get_be32(f);