diff options
Diffstat (limited to 'hw/9pfs')
| -rw-r--r-- | hw/9pfs/9p.h | 5 | ||||
| -rw-r--r-- | hw/9pfs/virtio-9p-device.c | 8 |
2 files changed, 8 insertions, 5 deletions
diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h index c886ba78d2..aac1b0b2ce 100644 --- a/hw/9pfs/9p.h +++ b/hw/9pfs/9p.h @@ -124,6 +124,11 @@ typedef struct { uint8_t id; uint16_t tag_le; } QEMU_PACKED P9MsgHeader; +/* According to the specification, 9p messages start with a 7-byte header. + * Since most of the code uses this header size in literal form, we must be + * sure this is indeed the case. + */ +QEMU_BUILD_BUG_ON(sizeof(P9MsgHeader) != 7); struct V9fsPDU { diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c index 3380bfc0c5..1a68c1622d 100644 --- a/hw/9pfs/virtio-9p-device.c +++ b/hw/9pfs/virtio-9p-device.c @@ -53,17 +53,15 @@ static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq) goto out_free_pdu; } - if (elem->in_num == 0) { + if (iov_size(elem->in_sg, elem->in_num) < 7) { virtio_error(vdev, "The guest sent a VirtFS request without space for " "the reply"); goto out_free_req; } - QEMU_BUILD_BUG_ON(sizeof(out) != 7); - len = iov_to_buf(elem->out_sg, elem->out_num, 0, - &out, sizeof(out)); - if (len != sizeof(out)) { + len = iov_to_buf(elem->out_sg, elem->out_num, 0, &out, 7); + if (len != 7) { virtio_error(vdev, "The guest sent a malformed VirtFS request: " "header size is %zd, should be 7", len); goto out_free_req; |