tun: relax check on eth_get_headlen() return value
authorEric Dumazet <edumazet@google.com>
Tue, 17 Oct 2017 17:07:44 +0000 (10:07 -0700)
committerDavid S. Miller <davem@davemloft.net>
Thu, 19 Oct 2017 12:17:39 +0000 (13:17 +0100)
commit010f245b9dd734adda6386c494a4ace953ea8dc4
treee74de233d9da5944058f3a357b949160524f863c
parent22ce97fe49b5522e0f97b7c2282ed71a1abd7410
tun: relax check on eth_get_headlen() return value

syzkaller hit the WARN() in tun_get_user(), providing skb
with payload in fragments only, and nothing in skb->head

GRO layer is fine with this, so relax the check.

Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/tun.c