Commit e01bf1c8 authored Apr 12, 2008 by Rusty Russell Committed by David S. Miller Apr 12, 2008

net: check for underlength tap writes



If the user gives a packet under 14 bytes, we'll end up reading off the end
of the skb (not oopsing, just reading off the end).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Max Krasnyanskiy <maxk@qualcomm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 14daa021

drivers/net/tun.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -286,8 +286,11 @@ static __inline__ ssize_t tun_get_user(struct tun_struct tun, struct iovec iv,
		return -EFAULT;
		}

		if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV)
		if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
		align = NET_IP_ALIGN;
		if (unlikely(len < ETH_HLEN))
		return -EINVAL;
		}

		if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
		tun->dev->stats.rx_dropped++;