stable inclusion
from stable-5.10.13
commit 35c50e69af15e1cbcfbbca4ba7c0f8ed7fb8566c
bugzilla: 47995

--------------------------------

[ Upstream commit 1b0b0b58 ]

This patch is based on a similar change to i40e by Slawomir Laba:
"i40e: Implement flow for IPv6 next header (extension header)".

When a packet contains an IPv6 header with next header which is
an extension header and not a protocol one, the kernel function
skb_transport_header called with such sk_buff will return a
pointer to the extension header and not to the TCP one.

The above explained call caused a problem with packet processing
for skb with encapsulation for tunnel with ICE_TX_CTX_EIPT_IPV6.
The extension header was not skipped at all.

The ipv6_skip_exthdr function does check if next header of the IPV6
header is an extension header and doesn't modify the l4_proto pointer
if it points to a protocol header value so its safe to omit the
comparison of exthdr and l4.hdr pointers. The ipv6_skip_exthdr can
return value -1. This means that the skipping process failed
and there is something wrong with the packet so it will be dropped.

Fixes: a4e82a81 ("ice: Add support for tunnel offloads")
Signed-off-by: NNick Nunley <nicholas.d.nunley@intel.com>
Tested-by: NTony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: NTony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>