From: NeilBrown <neilb@xxxxxxx> commit d47a5dc2888fd1b94adf1553068b8dad76cec96c upstream. 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> Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/sunrpc/auth_gss/svcauth_gss.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -817,9 +817,11 @@ svcauth_gss_register_pseudoflavor(u32 ps 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;
