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authorMichael S. Tsirkin <mst@redhat.com>2010-09-14 15:15:52 +0200
committerMichael S. Tsirkin <mst@redhat.com>2010-09-14 15:22:41 +0200
commitee05d6939ed17b55e9c2466af32c208e0d547eb8 (patch)
tree72c0737e0c0ac93a9fd58970f5c5d95ca3c67914
parent053d8f6622701f849fda2ca2c9ae596c13599ba9 (diff)
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>
-rw-r--r--drivers/vhost/net.c2
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;
}