diff options
| author |   Yan Zhai <yan@cloudflare.com> | 2023-07-13 10:28:00 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2023-07-14 10:29:20 +0100 |
| commit | 9840036786d90cea11a90d1f30b6dc003b34ee67 (patch) | |
| tree | 21e1f07a9d6b6d101a3c1e3d660110c75700874a /net/ipv4/udp_offload.c | |
| parent | net: ethernet: Remove repeating expression (diff) | |
| download | linux-9840036786d90cea11a90d1f30b6dc003b34ee67.tar.xz linux-9840036786d90cea11a90d1f30b6dc003b34ee67.zip | |
gso: fix dodgy bit handling for GSO_UDP_L4
Commit 1fd54773c267 ("udp: allow header check for dodgy GSO_UDP_L4
packets.") checks DODGY bit for UDP, but for packets that can be fed
directly to the device after gso_segs reset, it actually falls through
to fragmentation:
https://lore.kernel.org/all/CAJPywTKDdjtwkLVUW6LRA2FU912qcDmQOQGt2WaDo28KzYDg+A@mail.gmail.com/
This change restores the expected behavior of GSO_UDP_L4 packets.
Fixes: 1fd54773c267 ("udp: allow header check for dodgy GSO_UDP_L4 packets.")
Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/udp_offload.c')
| -rw-r--r-- | net/ipv4/udp_offload.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 75aa4de5b731..f402946da344 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -274,13 +274,20 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, __sum16 check; __be16 newlen; - if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) - return __udp_gso_segment_list(gso_skb, features, is_ipv6); - mss = skb_shinfo(gso_skb)->gso_size; if (gso_skb->len <= sizeof(*uh) + mss) return ERR_PTR(-EINVAL); + if (skb_gso_ok(gso_skb, features | NETIF_F_GSO_ROBUST)) { + /* Packet is from an untrusted source, reset gso_segs. */ + skb_shinfo(gso_skb)->gso_segs = DIV_ROUND_UP(gso_skb->len - sizeof(*uh), + mss); + return NULL; + } + + if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) + return __udp_gso_segment_list(gso_skb, features, is_ipv6); + skb_pull(gso_skb, sizeof(*uh)); /* clear destructor to avoid skb_segment assigning it to tail */ @@ -388,8 +395,7 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, if (!pskb_may_pull(skb, sizeof(struct udphdr))) goto out; - if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && - !skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) + if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) return __udp_gso_segment(skb, features, false); mss = skb_shinfo(skb)->gso_size; |