umh: creds: convert call_usermodehelper_keys() to use subprocess_info->init()

call_usermodehelper_keys() uses call_usermodehelper_setkeys() to change
subprocess_info->cred in advance.  Now that we have info->init() we can
change this code to set tgcred->session_keyring in context of execing
kernel thread.

Note: since currently call_usermodehelper_keys() is never called with
UMH_NO_WAIT, call_usermodehelper_keys()->key_get() and umh_keys_cleanup()
are not really needed, we could rely on install_session_keyring_to_cred()
which does key_get() on success.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 20a38fed61b1..6b8e4ff4cc68 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -216,8 +216,7 @@ static int install_process_keyring(void)
 /*
  * install a session keyring directly to a credentials struct
  */
-static int install_session_keyring_to_cred(struct cred *cred,
-                                           struct key *keyring)
+int install_session_keyring_to_cred(struct cred *cred, struct key *keyring)
 {
         unsigned long flags;
         struct key *old;