diff options
| author | Stefan Hajnoczi <stefanha@redhat.com> | 2018-04-11 10:35:40 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-19 08:56:16 +0200 |
| commit | e240ffd5a3bea24906ae2cd375ec7a6f4810a77d (patch) | |
| tree | b6db6942cc0fd96c9ccc2e56f80f459d704f5bcf /drivers/vhost | |
| parent | 381ebff25898e62d3e12ac9b9bc2acbd64e543d6 (diff) | |
vhost: fix vhost_vq_access_ok() log check
[ Upstream commit d14d2b78090c7de0557362b26a4ca591aa6a9faa ]
Commit d65026c6c62e7d9616c8ceb5a53b68bcdc050525 ("vhost: validate log
when IOTLB is enabled") introduced a regression. The logic was
originally:
if (vq->iotlb)
return 1;
return A && B;
After the patch the short-circuit logic for A was inverted:
if (A || vq->iotlb)
return A;
return B;
This patch fixes the regression by rewriting the checks in the obvious
way, no longer returning A when vq->iotlb is non-NULL (which is hard to
understand).
Reported-by: syzbot+65a84dde0214b0387ccd@syzkaller.appspotmail.com
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/vhost.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c692e0b13242..40552a043c86 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1252,10 +1252,12 @@ static int vq_log_access_ok(struct vhost_virtqueue *vq, /* Caller should have vq mutex and device mutex */ int vhost_vq_access_ok(struct vhost_virtqueue *vq) { - int ret = vq_log_access_ok(vq, vq->log_base); + if (!vq_log_access_ok(vq, vq->log_base)) + return 0; - if (ret || vq->iotlb) - return ret; + /* Access validation occurs at prefetch time with IOTLB */ + if (vq->iotlb) + return 1; return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used); } |