ipv6: add defensive check for CHECKSUM_PARTIAL skbs in ip_fragment
CHECKSUM_PARTIAL skbs should never arrive in ip_fragment. If we get one
of those warn about them once and handle them gracefully by recalculating
the checksum.
Fixes: commit 32dce968dd987 ("ipv6: Allow for partial checksums on non-ufo packets")
See-also: commit 72e843bb09d45 ("ipv6: ip6_fragment() should check CHECKSUM_PARTIAL")
Cc: Eric Dumazet <edumazet@google.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Benjamin Coddington <bcodding@redhat.com>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 81ac5a9..e6a7bd15 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -603,6 +603,10 @@
frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
&ipv6_hdr(skb)->saddr);
+ if (skb->ip_summed == CHECKSUM_PARTIAL &&
+ (err = skb_checksum_help(skb)))
+ goto fail;
+
hroom = LL_RESERVED_SPACE(rt->dst.dev);
if (skb_has_frag_list(skb)) {
int first_len = skb_pagelen(skb);
@@ -731,10 +735,6 @@
}
slow_path:
- if ((skb->ip_summed == CHECKSUM_PARTIAL) &&
- skb_checksum_help(skb))
- goto fail;
-
left = skb->len - hlen; /* Space per frame */
ptr = hlen; /* Where to start from */