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| author | Jason Wang <jasowang@redhat.com> | 2018-03-29 11:00:04 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-12 13:32:27 +0300 |
| commit | 2f8aa659d4c0b6f70d441022e955ff53bb9ffea5 (patch) | |
| tree | 256490b504f9f0cf73339913f52c053f2386bb56 /drivers/vhost | |
| parent | 72b880f43990c747aa83ca695f71344718d041f3 (diff) | |
| download | linux-2f8aa659d4c0b6f70d441022e955ff53bb9ffea5.tar.xz | |
vhost: validate log when IOTLB is enabled
[ Upstream commit d65026c6c62e7d9616c8ceb5a53b68bcdc050525 ]
Vq log_base is the userspace address of bitmap which has nothing to do
with IOTLB. So it needs to be validated unconditionally otherwise we
may try use 0 as log_base which may lead to pin pages that will lead
unexpected result (e.g trigger BUG_ON() in set_bit_to_user()).
Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API")
Reported-by: syzbot+6304bf97ef436580fede@syzkaller.appspotmail.com
Signed-off-by: Jason Wang <jasowang@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 | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c1033dc0e3f5..c692e0b13242 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1252,14 +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) { - if (vq->iotlb) { - /* When device IOTLB was used, the access validation - * will be validated during prefetching. - */ - return 1; - } - return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used) && - vq_log_access_ok(vq, vq->log_base); + int ret = vq_log_access_ok(vq, vq->log_base); + + if (ret || vq->iotlb) + return ret; + + return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used); } EXPORT_SYMBOL_GPL(vhost_vq_access_ok); |