Bug 15458

during a check of the current git head of the linux kernel with the static code
analysis tool cppcheck
(http://sourceforge.net/apps/mediawiki/cppcheck/index.php?title=Main_Page) the
tool discoverd a possible nullpointer derefefence in linux-2.6/net/sunrpc/xprt.c. Cppcheck printed the following message:

Possible null pointer dereference: req - otherwise it is redundant to check if req is null at line 209

Take a look at the source:
....
	struct rpc_rqst *req = task->tk_rqstp;
#199	struct rpc_xprt	*xprt = req->rq_xprt;

	if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
		if (task == xprt->snd_task)
			return 1;
		if (task == NULL)
			return 0;
		goto out_sleep;
	}
	xprt->snd_task = task;
#209	if (req) {
		req->rq_bytes_sent = 0;
		req->rq_ntrans++;
	}
	return 1;
....

As you can see, at line 199 the pointer req is allready dereferenced, so there is no need to check for a nullpointer at line 209. In order to make the code more stable, i would recommend to move the nullpointer check to line 199!

Best regards

Ettl Martin