During migration, the values read from migration stream during ram load
are not validated. Especially offset in host_from_stream_offset() and
also the length of the writes in the callers of said function.
To fix this, we need to make sure that the [offset, offset + length]
range fits into one of the allocated memory regions.
Validating addr < len should be sufficient since data seems to always be
managed in TARGET_PAGE_SIZE chunks.
Fixes: CVE-2014-7840
Note: follow-up patches add extra checks on each block->host access.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
uint8_t len;
if (flags & RAM_SAVE_FLAG_CONTINUE) {
- if (!block) {
+ if (!block || block->length <= offset) {
error_report("Ack, bad migration stream!");
return NULL;
}
id[len] = 0;
QTAILQ_FOREACH(block, &ram_list.blocks, next) {
- if (!strncmp(id, block->idstr, sizeof(id)))
+ if (!strncmp(id, block->idstr, sizeof(id)) && block->length > offset) {
return memory_region_get_ram_ptr(block->mr) + offset;
+ }
}
error_report("Can't find block %s!", id);