diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2011-12-23 15:39:03 +0100 |
|---|---|---|
| committer | Anthony Liguori <aliguori@us.ibm.com> | 2012-01-13 10:20:51 -0600 |
| commit | 1ba1f2e319afdcb485963cd3f426fdffd1b725f2 (patch) | |
| tree | 55412245b45b35211f3efeaae09732311c7ba075 /hw | |
| parent | 701a8f76aa5243d90a71935982c20c06d8e83b80 (diff) | |
virtio-blk: refuse SG_IO requests with scsi=off
QEMU does have a "scsi" option (to be used like -device
virtio-blk-pci,drive=foo,scsi=off). However, it only
masks the feature bit, and does not reject the command
if a malicious guest disregards the feature bits and
issues a request.
Without this patch, using scsi=off does not protect you
from CVE-2011-4127.
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/virtio-blk.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c index 5e81f53e14..5b416c36ee 100644 --- a/hw/virtio-blk.c +++ b/hw/virtio-blk.c @@ -153,6 +153,12 @@ static void virtio_blk_handle_scsi(VirtIOBlockReq *req) int status; int i; + if ((req->dev->vdev.guest_features & (1 << VIRTIO_BLK_F_SCSI)) == 0) { + virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP); + g_free(req); + return; + } + /* * We require at least one output segment each for the virtio_blk_outhdr * and the SCSI command block. |