balloon: Don't balloon roms

A broken guest can specify physical addresses that correspond
to any memory region, but it shouldn't be able to change ROM.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: qemu-stable@nongnu.org
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Dr. David Alan Gilbert 2016-12-16 11:41:55 +00:00 committed by Michael S. Tsirkin
parent e66bcc4081
commit f2fd57db36
2 changed files with 8 additions and 1 deletions

View File

@ -15,6 +15,8 @@ virtio_rng_pushed(void *rng, size_t len) "rng %p: %zd bytes pushed"
virtio_rng_request(void *rng, size_t size, unsigned quota) "rng %p: %zd bytes requested, %u bytes quota left"
# hw/virtio/virtio-balloon.c
#
virtio_balloon_bad_addr(uint64_t gpa) "%"PRIx64
virtio_balloon_handle_output(const char *name, uint64_t gpa) "section name: %s gpa: %"PRIx64
virtio_balloon_get_config(uint32_t num_pages, uint32_t actual) "num_pages: %d actual: %d"
virtio_balloon_set_config(uint32_t actual, uint32_t oldactual) "actual: %d oldactual: %d"

View File

@ -228,8 +228,13 @@ static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
/* FIXME: remove get_system_memory(), but how? */
section = memory_region_find(get_system_memory(), pa, 1);
if (!int128_nz(section.size) || !memory_region_is_ram(section.mr))
if (!int128_nz(section.size) ||
!memory_region_is_ram(section.mr) ||
memory_region_is_rom(section.mr) ||
memory_region_is_romd(section.mr)) {
trace_virtio_balloon_bad_addr(pa);
continue;
}
trace_virtio_balloon_handle_output(memory_region_name(section.mr),
pa);