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| author | Ilan Tayari <ilant@mellanox.com> | 2017-04-19 21:26:07 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-04-21 13:30:29 -0400 |
| commit | 43170c4e0ba709c79130c3fe5a41e66279950cd0 (patch) | |
| tree | b2ee11ce9dc26ae3649c22689427aef30bb0e4d8 /net | |
| parent | 918b70244f57920db8fcb5ae63e2d0c79b509821 (diff) | |
| download | linux-0-day-43170c4e0ba709c79130c3fe5a41e66279950cd0.tar.gz linux-0-day-43170c4e0ba709c79130c3fe5a41e66279950cd0.tar.xz | |
gso: Validate assumption of frag_list segementation
Commit 07b26c9454a2 ("gso: Support partial splitting at the frag_list
pointer") assumes that all SKBs in a frag_list (except maybe the last
one) contain the same amount of GSO payload.
This assumption is not always correct, resulting in the following
warning message in the log:
skb_segment: too many frags
For example, mlx5 driver in Striding RQ mode creates some RX SKBs with
one frag, and some with 2 frags.
After GRO, the frag_list SKBs end up having different amounts of payload.
If this frag_list SKB is then forwarded, the aforementioned assumption
is violated.
Validate the assumption, and fall back to software GSO if it not true.
Change-Id: Ia03983f4a47b6534dd987d7a2aad96d54d46d212
Fixes: 07b26c9454a2 ("gso: Support partial splitting at the frag_list pointer")
Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/skbuff.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 35c1e24602069..f86bf69cfb8d8 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3082,22 +3082,32 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, if (sg && csum && (mss != GSO_BY_FRAGS)) { if (!(features & NETIF_F_GSO_PARTIAL)) { struct sk_buff *iter; + unsigned int frag_len; if (!list_skb || !net_gso_ok(features, skb_shinfo(head_skb)->gso_type)) goto normal; - /* Split the buffer at the frag_list pointer. - * This is based on the assumption that all - * buffers in the chain excluding the last - * containing the same amount of data. + /* If we get here then all the required + * GSO features except frag_list are supported. + * Try to split the SKB to multiple GSO SKBs + * with no frag_list. + * Currently we can do that only when the buffers don't + * have a linear part and all the buffers except + * the last are of the same length. */ + frag_len = list_skb->len; skb_walk_frags(head_skb, iter) { + if (frag_len != iter->len && iter->next) + goto normal; if (skb_headlen(iter)) goto normal; len -= iter->len; } + + if (len != frag_len) + goto normal; } /* GSO partial only requires that we trim off any excess that |