macsec: limit replay window size with XPN
authorSabrina Dubroca <sd@queasysnail.net>
Fri, 22 Jul 2022 09:16:29 +0000 (11:16 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 3 Aug 2022 10:03:50 +0000 (12:03 +0200)
commita706a40d42f482ae3f03998a63dfdc8a8f3640c4
treeed23a5f9d367234fc81f65f248a4e9873e4db29b
parent6ad56d5c4f98ed160b1db463e0d56e6be7ab77a0
macsec: limit replay window size with XPN

[ Upstream commit b07a0e2044057f201d694ab474f5c42a02b6465b ]

IEEE 802.1AEbw-2013 (section 10.7.8) specifies that the maximum value
of the replay window is 2^30-1, to help with recovery of the upper
bits of the PN.

To avoid leaving the existing macsec device in an inconsistent state
if this test fails during changelink, reuse the cleanup mechanism
introduced for HW offload. This wasn't needed until now because
macsec_changelink_common could not fail during changelink, as
modifying the cipher suite was not allowed.

Finally, this must happen after handling IFLA_MACSEC_CIPHER_SUITE so
that secy->xpn is set.

Fixes: 48ef50fa866a ("macsec: Netlink support of XPN cipher suites (IEEE 802.1AEbw)")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/net/macsec.c