As reported in https://bugzilla.kernel.org/show_bug.cgi?id=206651 there are problems with sunrpc/svc flavour registration. This can be demonstrated as a memory-leak if you load the rpcsec_gss_krb5 module, then unload the sunrpc module and all dependents. This action leaks 3 kmalloc-64 slab entires, and some strings. The possible consequences are worse. If only unload rpcsec_gss_krb5 and reload just that, it will allow the old registered flavour handlers to be used, and they will include pointers into memory which has since been freed and possibly reused. This can result in undesired behaviour. The first patch makes the leak apparent with a WARNing, the second prevents it but also prevents module reload, the third removes the incorrect behaviour so the module can be safely unloaded and reloaded. I think all are suitable for -stable, but I haven't determined appropriate 'Fixes:' tags. NeilBrown --- NeilBrown (3): sunrpc: check that domain table is empty at module unload. sunrpc: svcauth_gss_register_pseudoflavor must reject duplicate registrations. sunrpc: clean up properly in gss_mech_unregister() include/linux/sunrpc/gss_api.h | 1 + include/linux/sunrpc/svcauth_gss.h | 3 ++- net/sunrpc/auth_gss/gss_mech_switch.c | 12 +++++++++--- net/sunrpc/auth_gss/svcauth_gss.c | 17 ++++++++++------- net/sunrpc/sunrpc.h | 1 + net/sunrpc/sunrpc_syms.c | 2 ++ net/sunrpc/svcauth.c | 18 ++++++++++++++++++ 7 files changed, 43 insertions(+), 11 deletions(-) -- Signature
