[PATCH 5.12 275/296] ipv6: record frag_max_size in atomic fragments in input path

Greg Kroah-Hartman
2021-05-31T16:49:50Z

From: Francesco Ruggeri <fruggeri@arista.com>

[ Upstream commit e29f011e8fc04b2cdc742a2b9bbfa1b62518381a ]

Commit dbd1759e6a9c ("ipv6: on reassembly, record frag_max_size")
filled the frag_max_size field in IP6CB in the input path.
The field should also be filled in case of atomic fragments.

Fixes: dbd1759e6a9c ('ipv6: on reassembly, record frag_max_size')
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv6/reassembly.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 47a0dc46cbdb..28e44782c94d 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -343,7 +343,7 @@ static int ipv6_frag_rcv(struct sk_buff *skb)
hdr = ipv6_hdr(skb);
fhdr = (struct frag_hdr *)skb_transport_header(skb);

- if (!(fhdr->frag_off & htons(0xFFF9))) {
+ if (!(fhdr->frag_off & htons(IP6_OFFSET | IP6_MF))) {
/* It is not a fragmented frame */
skb->transport_header += sizeof(struct frag_hdr);
__IP6_INC_STATS(net,
@@ -351,6 +351,8 @@ static int ipv6_frag_rcv(struct sk_buff *skb)

IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
IP6CB(skb)->flags |= IP6SKB_FRAGMENTED;
+ IP6CB(skb)->frag_max_size = ntohs(hdr->payload_len) +
+ sizeof(struct ipv6hdr);
return 1;
}

--
2.30.2