diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2013-03-17 03:46:09 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-03-17 19:28:54 +0100 |
| commit | 46aa92d1ba162b4b3d6b7102440e459d4e4ee255 (patch) | |
| tree | 98dd50e4b0420724c04fe00b188155fcb41a4476 | |
| parent | bridge: Add support for setting BR_ROOT_BLOCK flag. (diff) | |
| download | linux-46aa92d1ba162b4b3d6b7102440e459d4e4ee255.tar.xz linux-46aa92d1ba162b4b3d6b7102440e459d4e4ee255.zip | |
vhost/net: fix heads usage of ubuf_info
ubuf info allocator uses guest controlled head as an index,
so a malicious guest could put the same head entry in the ring twice,
and we will get two callbacks on the same value.
To fix use upend_idx which is guaranteed to be unique.
Reported-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/vhost/net.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 959b1cd89e6a..ec6fb3fa59bb 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -339,7 +339,8 @@ static void handle_tx(struct vhost_net *net) msg.msg_controllen = 0; ubufs = NULL; } else { - struct ubuf_info *ubuf = &vq->ubuf_info[head]; + struct ubuf_info *ubuf; + ubuf = vq->ubuf_info + vq->upend_idx; vq->heads[vq->upend_idx].len = VHOST_DMA_IN_PROGRESS; |