tun: Fix crash with non-GSO users
When I made the tun driver use non-linear packets as the preferred
option, it broke non-GSO users because they would end up allocating
a completely non-linear packet, which triggers a crash when we call
eth_type_trans.
This patch reverts non-GSO users to using linear packets and adds
a check to ensure that GSO users can't cause crashes in the same
way.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index a1b0697..16716ae 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -518,7 +518,7 @@
int err;
/* Under a page? Don't bother with paged skb. */
- if (prepad + len < PAGE_SIZE)
+ if (prepad + len < PAGE_SIZE || !linear)
linear = len;
skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
@@ -565,7 +565,8 @@
if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
align = NET_IP_ALIGN;
- if (unlikely(len < ETH_HLEN))
+ if (unlikely(len < ETH_HLEN ||
+ (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
return -EINVAL;
}