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| author | Ilya Dryomov <idryomov@gmail.com> | 2018-07-27 19:18:34 +0200 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2018-08-02 21:33:24 +0200 |
| commit | 6daca13d2e72bedaaacfc08f873114c9307d5aea (patch) | |
| tree | 97278ec273414431dd2fab13ccbc3a5d98140cec /fs/ceph/mds_client.c | |
| parent | 149cac4a50b0b4081b38b2f38de6ef71c27eaa85 (diff) | |
| download | lwn-6daca13d2e72bedaaacfc08f873114c9307d5aea.tar.gz lwn-6daca13d2e72bedaaacfc08f873114c9307d5aea.zip | |
libceph: add authorizer challenge
When a client authenticates with a service, an authorizer is sent with
a nonce to the service (ceph_x_authorize_[ab]) and the service responds
with a mutation of that nonce (ceph_x_authorize_reply). This lets the
client verify the service is who it says it is but it doesn't protect
against a replay: someone can trivially capture the exchange and reuse
the same authorizer to authenticate themselves.
Allow the service to reject an initial authorizer with a random
challenge (ceph_x_authorize_challenge). The client then has to respond
with an updated authorizer proving they are able to decrypt the
service's challenge and that the new authorizer was produced for this
specific connection instance.
The accepting side requires this challenge and response unconditionally
if the client side advertises they have CEPHX_V2 feature bit.
This addresses CVE-2018-1128.
Link: http://tracker.ceph.com/issues/24836
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
Diffstat (limited to 'fs/ceph/mds_client.c')
| -rw-r--r-- | fs/ceph/mds_client.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index f5a299daae95..4fc7582233db 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -4154,6 +4154,16 @@ static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con, return auth; } +static int add_authorizer_challenge(struct ceph_connection *con, + void *challenge_buf, int challenge_buf_len) +{ + struct ceph_mds_session *s = con->private; + struct ceph_mds_client *mdsc = s->s_mdsc; + struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth; + + return ceph_auth_add_authorizer_challenge(ac, s->s_auth.authorizer, + challenge_buf, challenge_buf_len); +} static int verify_authorizer_reply(struct ceph_connection *con) { @@ -4217,6 +4227,7 @@ static const struct ceph_connection_operations mds_con_ops = { .put = con_put, .dispatch = dispatch, .get_authorizer = get_authorizer, + .add_authorizer_challenge = add_authorizer_challenge, .verify_authorizer_reply = verify_authorizer_reply, .invalidate_authorizer = invalidate_authorizer, .peer_reset = peer_reset, |