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| author | Alexey Kodanev <alexey.kodanev@oracle.com> | 2018-02-15 20:18:43 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2018-06-16 22:22:18 +0100 |
| commit | 29f22eed356176d55582bb25d02c0aaec2e37fa1 (patch) | |
| tree | 50f47f06f5687af0dea5e6190f71d9eba05e4219 | |
| parent | 86cfda63a76c89ab76954a95513b1647437cb910 (diff) | |
| download | linux-29f22eed356176d55582bb25d02c0aaec2e37fa1.tar.gz | |
udplite: fix partial checksum initialization
commit 15f35d49c93f4fa9875235e7bf3e3783d2dd7a1b upstream.
Since UDP-Lite is always using checksum, the following path is
triggered when calculating pseudo header for it:
udp4_csum_init() or udp6_csum_init()
skb_checksum_init_zero_check()
__skb_checksum_validate_complete()
The problem can appear if skb->len is less than CHECKSUM_BREAK. In
this particular case __skb_checksum_validate_complete() also invokes
__skb_checksum_complete(skb). If UDP-Lite is using partial checksum
that covers only part of a packet, the function will return bad
checksum and the packet will be dropped.
It can be fixed if we skip skb_checksum_init_zero_check() and only
set the required pseudo header checksum for UDP-Lite with partial
checksum before udp4_csum_init()/udp6_csum_init() functions return.
Fixes: ed70fcfcee95 ("net: Call skb_checksum_init in IPv4")
Fixes: e4f45b7f40bd ("net: Call skb_checksum_init in IPv6")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | include/net/udplite.h | 1 | ||||
| -rw-r--r-- | net/ipv4/udp.c | 5 | ||||
| -rw-r--r-- | net/ipv6/ip6_checksum.c | 5 |
3 files changed, 11 insertions, 0 deletions
diff --git a/include/net/udplite.h b/include/net/udplite.h index 2caadabcd07baf..3c89854899928f 100644 --- a/include/net/udplite.h +++ b/include/net/udplite.h @@ -61,6 +61,7 @@ static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh) UDP_SKB_CB(skb)->cscov = cscov; if (skb->ip_summed == CHECKSUM_COMPLETE) skb->ip_summed = CHECKSUM_NONE; + skb->csum_valid = 0; } return 0; diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 5877d782bdc190..41c96cacdbaa1c 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1729,6 +1729,11 @@ static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, err = udplite_checksum_init(skb, uh); if (err) return err; + + if (UDP_SKB_CB(skb)->partial_cov) { + skb->csum = inet_compute_pseudo(skb, proto); + return 0; + } } return skb_checksum_init_zero_check(skb, proto, uh->check, diff --git a/net/ipv6/ip6_checksum.c b/net/ipv6/ip6_checksum.c index 9a4d7322fb2223..391a8fedb27ed7 100644 --- a/net/ipv6/ip6_checksum.c +++ b/net/ipv6/ip6_checksum.c @@ -73,6 +73,11 @@ int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto) err = udplite_checksum_init(skb, uh); if (err) return err; + + if (UDP_SKB_CB(skb)->partial_cov) { + skb->csum = ip6_compute_pseudo(skb, proto); + return 0; + } } /* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels) |