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| author | Michael S. Tsirkin <mst@redhat.com> | 2010-09-14 15:15:52 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2010-09-14 15:22:41 +0200 |
| commit | ee05d6939ed17b55e9c2466af32c208e0d547eb8 (patch) | |
| tree | 72c0737e0c0ac93a9fd58970f5c5d95ca3c67914 /drivers/vhost | |
| parent | 053d8f6622701f849fda2ca2c9ae596c13599ba9 (diff) | |
| download | lwn-ee05d6939ed17b55e9c2466af32c208e0d547eb8.tar.gz lwn-ee05d6939ed17b55e9c2466af32c208e0d547eb8.zip | |
vhost-net: fix range checking in mrg bufs case
In mergeable buffer case, we use headcount, log_num
and seg as indexes in same-size arrays, and
we know that headcount <= seg and
log_num equals either 0 or seg.
Therefore, the right thing to do is range-check seg,
not headcount as we do now: these will be different
if guest chains s/g descriptors (this does not
happen now, but we can not trust the guest).
Long term, we should add BUG_ON checks to verify
two other indexes are what we think they should be.
Reported-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/net.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 29e850a7a2f9..7c8008225ee3 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -243,7 +243,7 @@ static int get_rx_bufs(struct vhost_virtqueue *vq, int r, nlogs = 0; while (datalen > 0) { - if (unlikely(headcount >= VHOST_NET_MAX_SG)) { + if (unlikely(seg >= VHOST_NET_MAX_SG)) { r = -ENOBUFS; goto err; } |