[LU-8192] Unsafe access to keyrings in gss_kt_instantiate

• Type: Bug
• Resolution: Unresolved
• Priority: Major
• Labels: patch x
• Severity: 3
• Assignee: Jeremy Filizetti
• Reporter: Oleg Drokin

Description

Apparently you cannot just fetch a keyring like:

rc = key_link(key_tgcred(current)->session_keyring, key);

This is unsafe and supposedly not even accessible, because sparse warns it's in wrong address space, also in
request_key_unlink():

                ring = key_get(rcu_dereference(key_tgcred(tsk)
                                               ->session_keyring));

The errors I get are:

lustre/ptlrpc/gss/gss_keyring.c:1308 warning: incorrect type in argument 1 (different address spaces) expected "struct key *keyring" got "struct key [noderef] <asn:4>*const [noderef] <asn:4>session_keyring"
lustre/ptlrpc/gss/gss_keyring.c:695 warning: cast removes address space of expression