diff options
| author | Harold Huang <baymaxhuang@gmail.com> | 2022-03-03 10:24:40 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-03-02 22:00:59 -0800 |
| commit | 74a335a07a17d131b9263bfdbdcb5e40673ca9ca (patch) | |
| tree | 0b6e1fe55e27bbca846fb3db4bad717e0bf699b9 /drivers/net/tun.c | |
| parent | fa452e0a609a038e5ef9d2e042bb80e08e1af7af (diff) | |
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>
Diffstat (limited to 'drivers/net/tun.c')
| -rw-r--r-- | drivers/net/tun.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 969ea69fd29d..2a0d8a5d7aec 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -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; |