Stefano Garzarella
2022-Nov-08 10:34 UTC
[PATCH 2/2] vhost: fix range used in translate_desc()
vhost_iotlb_itree_first() requires `start` and `last` parameters
to search for a mapping that overlaps the range.
In translate_desc() we cyclically call vhost_iotlb_itree_first(),
incrementing `addr` by the amount already translated, so rightly
we move the `start` parameter passed to vhost_iotlb_itree_first(),
but we should hold the `last` parameter constant.
Let's fix it by saving the `last` parameter value before incrementing
`addr` in the loop.
Fixes: 0bbe30668d89 ("vhost: factor out IOTLB")
Signed-off-by: Stefano Garzarella <sgarzare at redhat.com>
---
I'm not sure about the fixes tag. On the one I used this patch should
apply cleanly, but looking at the latest stable (4.9), maybe we should
use
Fixes: a9709d6874d5 ("vhost: convert pre sorted vhost memory array to
interval tree")
Suggestions?
---
drivers/vhost/vhost.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 40097826cff0..3c2359570df9 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2053,7 +2053,7 @@ static int translate_desc(struct vhost_virtqueue *vq, u64
addr, u32 len,
struct vhost_dev *dev = vq->dev;
struct vhost_iotlb *umem = dev->iotlb ? dev->iotlb : dev->umem;
struct iovec *_iov;
- u64 s = 0;
+ u64 s = 0, last = addr + len - 1;
int ret = 0;
while ((u64)len > s) {
@@ -2063,7 +2063,7 @@ static int translate_desc(struct vhost_virtqueue *vq, u64
addr, u32 len,
break;
}
- map = vhost_iotlb_itree_first(umem, addr, addr + len - 1);
+ map = vhost_iotlb_itree_first(umem, addr, last);
if (map == NULL || map->start > addr) {
if (umem != dev->iotlb) {
ret = -EFAULT;
--
2.38.1
On Tue, Nov 8, 2022 at 6:34 PM Stefano Garzarella <sgarzare at redhat.com> wrote:> > vhost_iotlb_itree_first() requires `start` and `last` parameters > to search for a mapping that overlaps the range. > > In translate_desc() we cyclically call vhost_iotlb_itree_first(), > incrementing `addr` by the amount already translated, so rightly > we move the `start` parameter passed to vhost_iotlb_itree_first(), > but we should hold the `last` parameter constant. > > Let's fix it by saving the `last` parameter value before incrementing > `addr` in the loop. > > Fixes: 0bbe30668d89 ("vhost: factor out IOTLB") > Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> > --- > > I'm not sure about the fixes tag. On the one I used this patch should > apply cleanly, but looking at the latest stable (4.9), maybe we should > use > > Fixes: a9709d6874d5 ("vhost: convert pre sorted vhost memory array to interval tree")I think this should be the right commit to fix. Other than this Acked-by: Jason Wang <jasowang at redhat.com> Thanks> > Suggestions? > --- > drivers/vhost/vhost.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index 40097826cff0..3c2359570df9 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -2053,7 +2053,7 @@ static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, > struct vhost_dev *dev = vq->dev; > struct vhost_iotlb *umem = dev->iotlb ? dev->iotlb : dev->umem; > struct iovec *_iov; > - u64 s = 0; > + u64 s = 0, last = addr + len - 1; > int ret = 0; > > while ((u64)len > s) { > @@ -2063,7 +2063,7 @@ static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, > break; > } > > - map = vhost_iotlb_itree_first(umem, addr, addr + len - 1); > + map = vhost_iotlb_itree_first(umem, addr, last); > if (map == NULL || map->start > addr) { > if (umem != dev->iotlb) { > ret = -EFAULT; > -- > 2.38.1 >