Messages in this thread | | | Subject | Re: [PATCH v2 1/4] tcp: md5: Fix overlap between vrf and non-vrf keys | From | David Ahern <> | Date | Wed, 13 Oct 2021 21:05:39 -0600 |
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On 10/13/21 12:50 AM, Leonard Crestez wrote: > With net.ipv4.tcp_l3mdev_accept=1 it is possible for a listen socket to > accept connection from the same client address in different VRFs. It is > also possible to set different MD5 keys for these clients which differ > only in the tcpm_l3index field. > > This appears to work when distinguishing between different VRFs but not > between non-VRF and VRF connections. In particular: > > * tcp_md5_do_lookup_exact will match a non-vrf key against a vrf key. > This means that adding a key with l3index != 0 after a key with l3index > == 0 will cause the earlier key to be deleted. Both keys can be present > if the non-vrf key is added later. > * _tcp_md5_do_lookup can match a non-vrf key before a vrf key. This > casues failures if the passwords differ. > > Fix this by making tcp_md5_do_lookup_exact perform an actual exact > comparison on l3index and by making __tcp_md5_do_lookup perfer > vrf-bound keys above other considerations like prefixlen. > > Fixes: dea53bb80e07 ("tcp: Add l3index to tcp_md5sig_key and md5 functions") > Signed-off-by: Leonard Crestez <cdleonard@gmail.com> > --- > net/ipv4/tcp_ipv4.c | 19 ++++++++++++++++--- > 1 file changed, 16 insertions(+), 3 deletions(-) >
Reviewed-by: David Ahern <dsahern@kernel.org>
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