[PATCH] KEYS: unlock tasklist when exiting early from keyctl_session_to_parent

[Marc Dionne <marc.c.dionne@gmail.com>]

When we exit early from keyctl_session_to_parent because of permissions
or because the session keyring is the same as the parent, we need to
unlock the tasklist.

The missing unlock causes the system to hang completely when
using keyctl(KEYCTL_SESSION_TO_PARENT) with a keyring shared with
the parent.

Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com>
---
 security/keys/keyctl.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 74c9685..60983f3 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1319,6 +1319,7 @@ long keyctl_session_to_parent(void)
 already_same:
 	ret = 0;
 not_permitted:
+	write_unlock_irq(&tasklist_lock);
 	put_cred(cred);
 	return ret;
 
-- 
1.6.4.2