tuntap: add sanity checks about msg_controllen in sendmsg

In patch [1], tun_msg_ctl was added to allow pass batched xdp buffers to
tun_sendmsg. Although we donot use msg_controllen in this path, we should
check msg_controllen to make sure the caller pass a valid msg_ctl.

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fe8dd45bb7556246c6b76277b1ba4296c91c2505

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Harold Huang <baymaxhuang@gmail.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20220303022441.383865-1-baymaxhuang@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Harold Huang 2022-03-03 10:24:40 +08:00 committed by Jakub Kicinski
parent fa452e0a60
commit 74a335a07a
3 changed files with 5 additions and 2 deletions

View File

@ -1198,7 +1198,8 @@ static int tap_sendmsg(struct socket *sock, struct msghdr *m,
struct xdp_buff *xdp;
int i;
if (ctl && (ctl->type == TUN_MSG_PTR)) {
if (m->msg_controllen == sizeof(struct tun_msg_ctl) &&
ctl && ctl->type == TUN_MSG_PTR) {
for (i = 0; i < ctl->num; i++) {
xdp = &((struct xdp_buff *)ctl->ptr)[i];
tap_get_user_xdp(q, xdp);

View File

@ -2501,7 +2501,8 @@ static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
if (!tun)
return -EBADFD;
if (ctl && (ctl->type == TUN_MSG_PTR)) {
if (m->msg_controllen == sizeof(struct tun_msg_ctl) &&
ctl && ctl->type == TUN_MSG_PTR) {
struct tun_page tpage;
int n = ctl->num;
int flush = 0, queued = 0;

View File

@ -473,6 +473,7 @@ static void vhost_tx_batch(struct vhost_net *net,
goto signal_used;
msghdr->msg_control = &ctl;
msghdr->msg_controllen = sizeof(ctl);
err = sock->ops->sendmsg(sock, msghdr, 0);
if (unlikely(err < 0)) {
vq_err(&nvq->vq, "Fail to batch sending packets\n");