zaurus: fix buffer overrun on invalid state load

CVE-2013-4540

Within scoop_gpio_handler_update, if prev_level has a high bit set, then
we get bit > 16 and that causes a buffer overrun.

Since prev_level comes from wire indirectly, this can
happen on invalid state load.

Similarly for gpio_level and gpio_dir.

To fix, limit to 16 bit.

Reported-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2014-04-03 19:52:13 +03:00 committed by Juan Quintela
parent 5193be3be3
commit 52f91c3723
1 changed files with 10 additions and 0 deletions

View File

@ -203,6 +203,15 @@ static bool is_version_0 (void *opaque, int version_id)
return version_id == 0;
}
static bool vmstate_scoop_validate(void *opaque, int version_id)
{
ScoopInfo *s = opaque;
return !(s->prev_level & 0xffff0000) &&
!(s->gpio_level & 0xffff0000) &&
!(s->gpio_dir & 0xffff0000);
}
static const VMStateDescription vmstate_scoop_regs = {
.name = "scoop",
.version_id = 1,
@ -215,6 +224,7 @@ static const VMStateDescription vmstate_scoop_regs = {
VMSTATE_UINT32(gpio_level, ScoopInfo),
VMSTATE_UINT32(gpio_dir, ScoopInfo),
VMSTATE_UINT32(prev_level, ScoopInfo),
VMSTATE_VALIDATE("irq levels are 16 bit", vmstate_scoop_validate),
VMSTATE_UINT16(mcr, ScoopInfo),
VMSTATE_UINT16(cdr, ScoopInfo),
VMSTATE_UINT16(ccr, ScoopInfo),