savevm: fix corruption in vmstate_subsection_load().

Although it's rare to happen in live migration, when the head of a
byte stream contains 0x05 which is the marker of subsection, the
loader gets corrupted because vmstate_subsection_load() continues even
the device doesn't require it.  This patch adds a checker whether
subsection is needed, and skips following routines if not needed.

Signed-off-by: Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Yoshiaki Tamura 2011-02-03 13:34:08 +09:00 committed by Anthony Liguori
parent bfddb47a34
commit eb60260de0

View File

@ -1638,6 +1638,12 @@ static const VMStateDescription *vmstate_get_subsection(const VMStateSubsection
static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
void *opaque)
{
const VMStateSubsection *sub = vmsd->subsections;
if (!sub || !sub->needed) {
return 0;
}
while (qemu_peek_byte(f) == QEMU_VM_SUBSECTION) {
char idstr[256];
int ret;
@ -1650,10 +1656,11 @@ static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
idstr[len] = 0;
version_id = qemu_get_be32(f);
sub_vmsd = vmstate_get_subsection(vmsd->subsections, idstr);
sub_vmsd = vmstate_get_subsection(sub, idstr);
if (sub_vmsd == NULL) {
return -ENOENT;
}
assert(!sub_vmsd->subsections);
ret = vmstate_load_state(f, sub_vmsd, opaque, version_id);
if (ret) {
return ret;
@ -1677,6 +1684,7 @@ static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd,
qemu_put_byte(f, len);
qemu_put_buffer(f, (uint8_t *)vmsd->name, len);
qemu_put_be32(f, vmsd->version_id);
assert(!vmsd->subsections);
vmstate_save_state(f, vmsd, opaque);
}
sub++;