Re: [PATCH] SUNRPC: Fix possible NULL pointer dereference

Hi Trond,

On Mon, Feb 25, 2013 at 4:05 AM, Myklebust, Trond
[off-list ref] wrote:

On Mon, 2013-02-25 at 03:53 +0530, Syam Sidhardhan wrote:

quoted

Check for cred == NULL has to be done before accessing cred.

Signed-off-by: Syam Sidhardhan <redacted>
---
 net/sunrpc/auth.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index f529404..18678a6 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c

@@ -695,10 +695,13 @@ rpcauth_invalcred(struct rpc_task *task)
 {
      struct rpc_cred *cred = task->tk_rqstp->rq_cred;

+     if (cred == NULL)
+             return;
+
      dprintk("RPC: %5u invalidating %s cred %p\n",
              task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
-     if (cred)
-             clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+
+     clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 }

 int

Do we need that check at all?

I'm not sure whether we need that check or not. However
similar functions such as rpcauth_refreshcred(), rpcauth_uptodatecred() etc
are doing the same check inside. Cppcheck is throwing an error too.

Regards,
Syam
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html