KEYS: keyctl_get_keyring_ID() should create a session keyring if create flag set
The keyctl call:
keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 1)
should create a session keyring if the process doesn't have one of its own
because the create flag argument is set - rather than subscribing to and
returning the user-session keyring as:
keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 0)
will do.
This can be tested by commenting out pam_keyinit in the /etc/pam.d files and
running the following program a couple of times in a row:
#include <stdio.h>
#include <stdlib.h>
#include <keyutils.h>
int main(int argc, char *argv[])
{
key_serial_t uk, usk, sk, nsk;
uk = keyctl_get_keyring_ID(KEY_SPEC_USER_KEYRING, 0);
usk = keyctl_get_keyring_ID(KEY_SPEC_USER_SESSION_KEYRING, 0);
sk = keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 0);
nsk = keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 1);
printf("keys: %08x %08x %08x %08x\n", uk, usk, sk, nsk);
return 0;
}
Without this patch, I see:
keys: 3975ddc7 119c0c66 119c0c66 119c0c66
keys: 3975ddc7 119c0c66 119c0c66 119c0c66
With this patch, I see:
keys: 2cb4997b 34112878 34112878 17db2ce3
keys: 2cb4997b 34112878 34112878 39f3c73e
As can be seen, the session keyring starts off the same as the user-session
keyring each time, but with the patch a new session keyring is created when
the create flag is set.
Reported-by: Greg Wettstein <greg@enjellic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Greg Wettstein <greg@enjellic.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 3bc6071..1068cb1 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -589,12 +589,22 @@
ret = install_user_keyrings();
if (ret < 0)
goto error;
- ret = install_session_keyring(
- cred->user->session_keyring);
+ if (lflags & KEY_LOOKUP_CREATE)
+ ret = join_session_keyring(NULL);
+ else
+ ret = install_session_keyring(
+ cred->user->session_keyring);
if (ret < 0)
goto error;
goto reget_creds;
+ } else if (cred->tgcred->session_keyring ==
+ cred->user->session_keyring &&
+ lflags & KEY_LOOKUP_CREATE) {
+ ret = join_session_keyring(NULL);
+ if (ret < 0)
+ goto error;
+ goto reget_creds;
}
rcu_read_lock();