diff options
author | Michael S. Tsirkin <mst@redhat.com> | 2013-03-17 02:46:09 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-28 19:17:21 (GMT) |
commit | 82ad1a1163aae6fb9a0bb0d370a81a8d919ff7b5 (patch) | |
tree | 169a94de70eed08fc7ab0a0728bf75867f99a95a /drivers | |
parent | 0bf2c46258b0ace08dc5e27b732d24606adc3b2e (diff) | |
download | linux-fsl-qoriq-82ad1a1163aae6fb9a0bb0d370a81a8d919ff7b5.tar.xz |
vhost/net: fix heads usage of ubuf_info
[ Upstream commit 46aa92d1ba162b4b3d6b7102440e459d4e4ee255 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-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 959b1cd..ec6fb3f 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; |