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| author | Greg Kurz <groug@kaod.org> | 2020-10-03 12:01:52 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2020-10-04 03:43:03 -0400 |
| commit | 0210a8db2aeca393fb3067e234967877e3146266 (patch) | |
| tree | 43deeb36d07efb02ea3695934c31c2bf3ebd894d | |
| parent | 37787e9f81e2e586b526ff5c29c94e4f41513e80 (diff) | |
| download | linux-stable-0210a8db2aeca393fb3067e234967877e3146266.tar.gz linux-stable-0210a8db2aeca393fb3067e234967877e3146266.tar.bz2 linux-stable-0210a8db2aeca393fb3067e234967877e3146266.zip | |
vhost: Don't call access_ok() when using IOTLB
When the IOTLB device is enabled, the vring addresses we get
from userspace are GIOVAs. It is thus wrong to pass them down
to access_ok() which only takes HVAs.
Access validation is done at prefetch time with IOTLB. Teach
vq_access_ok() about that by moving the (vq->iotlb) check
from vhost_vq_access_ok() to vq_access_ok(). This prevents
vhost_vring_set_addr() to fail when verifying the accesses.
No behavior change for vhost_vq_access_ok().
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1883084
Fixes: 6b1e6cc7855b ("vhost: new device IOTLB API")
Cc: jasowang@redhat.com
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Greg Kurz <groug@kaod.org>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/160171931213.284610.2052489816407219136.stgit@bahia.lan
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| -rw-r--r-- | drivers/vhost/vhost.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index b45519ca66a7..c3b49975dc28 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1290,6 +1290,11 @@ static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, vring_used_t __user *used) { + /* If an IOTLB device is present, the vring addresses are + * GIOVAs. Access validation occurs at prefetch time. */ + if (vq->iotlb) + return true; + return access_ok(desc, vhost_get_desc_size(vq, num)) && access_ok(avail, vhost_get_avail_size(vq, num)) && access_ok(used, vhost_get_used_size(vq, num)); @@ -1383,10 +1388,6 @@ bool vhost_vq_access_ok(struct vhost_virtqueue *vq) if (!vq_log_access_ok(vq, vq->log_base)) return false; - /* Access validation occurs at prefetch time with IOTLB */ - if (vq->iotlb) - return true; - return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used); } EXPORT_SYMBOL_GPL(vhost_vq_access_ok); |