Fix the following RCU warning:
===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
security/keys/request_key.c:116 invoked rcu_dereference_check() without protection!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 0
1 lock held by keyctl/5372:
#0: (key_types_sem){.+.+.+}, at: [<ffffffff811a4e3d>] key_type_lookup+0x1c/0x70
stack backtrace:
Pid: 5372, comm: keyctl Not tainted 2.6.34-rc3-cachefs #150
Call Trace:
[<ffffffff810515f8>] lockdep_rcu_dereference+0xaa/0xb2
[<ffffffff811a9220>] call_sbin_request_key+0x156/0x2b6
[<ffffffff811a4c66>] ? __key_instantiate_and_link+0xb1/0xdc
[<ffffffff811a4cd3>] ? key_instantiate_and_link+0x42/0x5f
[<ffffffff811a96b8>] ? request_key_auth_new+0x17b/0x1f3
[<ffffffff811a8e00>] ? request_key_and_link+0x271/0x400
[<ffffffff810aba6f>] ? kmem_cache_alloc+0xe1/0x118
[<ffffffff811a8f1a>] request_key_and_link+0x38b/0x400
[<ffffffff811a7b72>] sys_request_key+0xf7/0x14a
[<ffffffff81052227>] ? trace_hardirqs_on_caller+0x10c/0x130
[<ffffffff81393f5c>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[<ffffffff81001eeb>] system_call_fastpath+0x16/0x1b
This was caused by doing:
[root@andromeda ~]# keyctl newring fred @s
539196288
[root@andromeda ~]# keyctl request2 user a a 539196288
request_key: Required key not available
Signed-off-by: David Howells <dhowells@redhat.com>
---
security/keys/request_key.c | 13 ++++++++-----
1 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 03fe63e..ea97c31 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -68,7 +68,8 @@ static int call_sbin_request_key(struct key_construction *cons,
{
const struct cred *cred = current_cred();
key_serial_t prkey, sskey;
- struct key *key = cons->key, *authkey = cons->authkey, *keyring;
+ struct key *key = ...
