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| author | Willem de Bruijn <willemb@google.com> | 2020-05-30 22:41:31 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-06-01 22:01:46 +0300 |
| commit | 96aa1b22bd6bb9fccf62f6261f390ed6f3e7967f (patch) | |
| tree | 36eef58c8426bc69d7db97739101bf11ebc887af | |
| parent | 4e4f4ce6abf5f6a8df0561776d3a790d60d519d0 (diff) | |
| download | linux-96aa1b22bd6bb9fccf62f6261f390ed6f3e7967f.tar.xz | |
tun: correct header offsets in napi frags mode
Tun in IFF_NAPI_FRAGS mode calls napi_gro_frags. Unlike netif_rx and
netif_gro_receive, this expects skb->data to point to the mac layer.
But skb_probe_transport_header, __skb_get_hash_symmetric, and
xdp_do_generic in tun_get_user need skb->data to point to the network
header. Flow dissection also needs skb->protocol set, so
eth_type_trans has to be called.
Ensure the link layer header lies in linear as eth_type_trans pulls
ETH_HLEN. Then take the same code paths for frags as for not frags.
Push the link layer header back just before calling napi_gro_frags.
By pulling up to ETH_HLEN from frag0 into linear, this disables the
frag0 optimization in the special case when IFF_NAPI_FRAGS is used
with zero length iov[0] (and thus empty skb->linear).
Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Petar Penkov <ppenkov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/tun.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index c54f967e2c66..b0ab882c021e 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1872,8 +1872,11 @@ drop: skb->dev = tun->dev; break; case IFF_TAP: - if (!frags) - skb->protocol = eth_type_trans(skb, tun->dev); + if (frags && !pskb_may_pull(skb, ETH_HLEN)) { + err = -ENOMEM; + goto drop; + } + skb->protocol = eth_type_trans(skb, tun->dev); break; } @@ -1930,9 +1933,12 @@ drop: } if (frags) { + u32 headlen; + /* Exercise flow dissector code path. */ - u32 headlen = eth_get_headlen(tun->dev, skb->data, - skb_headlen(skb)); + skb_push(skb, ETH_HLEN); + headlen = eth_get_headlen(tun->dev, skb->data, + skb_headlen(skb)); if (unlikely(headlen > skb_headlen(skb))) { this_cpu_inc(tun->pcpu_stats->rx_dropped); |