diff options
| author | Benoît Monin <benoit.monin@gmx.fr> | 2024-10-24 16:01:54 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-10-30 18:21:30 -0700 |
| commit | 04c20a9356f283da623903e81e7c6d5df7e4dc3c (patch) | |
| tree | 41624ce9adc60a43fcd523ecb498208cfa37a66b /net/core | |
| parent | c05c62850a8f035a267151dd86ea3daf887e28b8 (diff) | |
| download | linux-stable-04c20a9356f283da623903e81e7c6d5df7e4dc3c.tar.gz linux-stable-04c20a9356f283da623903e81e7c6d5df7e4dc3c.tar.bz2 linux-stable-04c20a9356f283da623903e81e7c6d5df7e4dc3c.zip | |
net: skip offload for NETIF_F_IPV6_CSUM if ipv6 header contains extension
As documented in skbuff.h, devices with NETIF_F_IPV6_CSUM capability
can only checksum TCP and UDP over IPv6 if the IP header does not
contains extension.
This is enforced for UDP packets emitted from user-space to an IPv6
address as they go through ip6_make_skb(), which calls
__ip6_append_data() where a check is done on the header size before
setting CHECKSUM_PARTIAL.
But the introduction of UDP encapsulation with fou6 added a code-path
where it is possible to get an skb with a partial UDP checksum and an
IPv6 header with extension:
* fou6 adds a UDP header with a partial checksum if the inner packet
does not contains a valid checksum.
* ip6_tunnel adds an IPv6 header with a destination option extension
header if encap_limit is non-zero (the default value is 4).
The thread linked below describes in more details how to reproduce the
problem with GRE-in-UDP tunnel.
Add a check on the network header size in skb_csum_hwoffload_help() to
make sure no IPv6 packet with extension header is handed to a network
device with NETIF_F_IPV6_CSUM capability.
Link: https://lore.kernel.org/netdev/26548921.1r3eYUQgxm@benoit.monin/T/#u
Fixes: aa3463d65e7b ("fou: Add encap ops for IPv6 tunnels")
Signed-off-by: Benoît Monin <benoit.monin@gmx.fr>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/5fbeecfc311ea182aa1d1c771725ab8b4cac515e.1729778144.git.benoit.monin@gmx.fr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/dev.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index ea5fbcd133ae..8453e14d301b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3639,6 +3639,9 @@ int skb_csum_hwoffload_help(struct sk_buff *skb, return 0; if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) { + if (vlan_get_protocol(skb) == htons(ETH_P_IPV6) && + skb_network_header_len(skb) != sizeof(struct ipv6hdr)) + goto sw_checksum; switch (skb->csum_offset) { case offsetof(struct tcphdr, check): case offsetof(struct udphdr, check): @@ -3646,6 +3649,7 @@ int skb_csum_hwoffload_help(struct sk_buff *skb, } } +sw_checksum: return skb_checksum_help(skb); } EXPORT_SYMBOL(skb_csum_hwoffload_help); |