tree b5236cc444fc7abf63afe37a7ed567c2cf404f22
parent 51c017707f192325e67810ef8c45d1098865f408
author Xin Long <lucien.xin@gmail.com> 1586509561 +0800
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1591165184 +0200

xfrm: allow to accept packets with ipv6 NEXTHDR_HOP in xfrm_input

commit afcaf61be9d1dbdee5ec186d1dcc67b6b692180f upstream.

For beet mode, when it's ipv6 inner address with nexthdrs set,
the packet format might be:

    ----------------------------------------------------
    | outer  |     | dest |     |      |  ESP    | ESP |
    | IP hdr | ESP | opts.| TCP | Data | Trailer | ICV |
    ----------------------------------------------------

The nexthdr from ESP could be NEXTHDR_HOP(0), so it should
continue processing the packet when nexthdr returns 0 in
xfrm_input(). Otherwise, when ipv6 nexthdr is set, the
packet will be dropped.

I don't see any error cases that nexthdr may return 0. So
fix it by removing the check for nexthdr == 0.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>