There is no valid case for supporting duplicate pseudoflavor registrations. Currently the silent acceptance of such registrations is hiding a bug. The rpcsec_gss_krb5 module registers 2 flavours but does not unregister them, so if you load, unload, reload the module, it will happily continue to use the old registration which now has pointers to the memory were the module was originally loaded. This could lead to unexpected results. So disallow duplicate registrations. Link: https://bugzilla.kernel.org/show_bug.cgi?id=206651 Cc: stable@xxxxxxxxxxxxxxx (v2.6.12+) Signed-off-by: NeilBrown <neilb@xxxxxxx> --- net/sunrpc/auth_gss/svcauth_gss.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c index 50d93c49ef1a..49bb346a6215 100644 --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -826,9 +826,11 @@ svcauth_gss_register_pseudoflavor(u32 pseudoflavor, char * name) new->h.flavour = &svcauthops_gss; new->pseudoflavor = pseudoflavor; - stat = 0; test = auth_domain_lookup(name, &new->h); - if (test != &new->h) { /* Duplicate registration */ + if (test != &new->h) { + pr_warn("svc: duplicate registration of gss pseudo flavour %s.\n", + name); + stat = -EADDRINUSE; auth_domain_put(test); kfree(new->h.name); goto out_free_dom;
