Heinz points out that adding buffers to a broken virtqueue (which should "never happen") still works. Failing allows drivers to detect and complain about broken devices.
Now drivers are robust, we can add this extra check. Reported-by: Heinz Graalfs <[email protected]> Signed-off-by: Rusty Russell <[email protected]> --- drivers/virtio/virtio_ring.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 28b5338fff71..b74033dca384 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -203,6 +203,11 @@ static inline int virtqueue_add(struct virtqueue *_vq, BUG_ON(data == NULL); + if (unlikely(vq->broken)) { + END_USE(vq); + return -EIO; + } + #ifdef DEBUG { ktime_t now = ktime_get(); @@ -309,7 +314,7 @@ add_head: * Caller must ensure we don't call this with other virtqueue operations * at the same time (except where noted). * - * Returns zero or a negative error (ie. ENOSPC, ENOMEM). + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). */ int virtqueue_add_sgs(struct virtqueue *_vq, struct scatterlist *sgs[], @@ -347,7 +352,7 @@ EXPORT_SYMBOL_GPL(virtqueue_add_sgs); * Caller must ensure we don't call this with other virtqueue operations * at the same time (except where noted). * - * Returns zero or a negative error (ie. ENOSPC, ENOMEM). + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). */ int virtqueue_add_outbuf(struct virtqueue *vq, struct scatterlist sg[], unsigned int num, @@ -369,7 +374,7 @@ EXPORT_SYMBOL_GPL(virtqueue_add_outbuf); * Caller must ensure we don't call this with other virtqueue operations * at the same time (except where noted). * - * Returns zero or a negative error (ie. ENOSPC, ENOMEM). + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). */ int virtqueue_add_inbuf(struct virtqueue *vq, struct scatterlist sg[], unsigned int num, -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
