DMA: PL330: Check the pointer returned by kzalloc

commit 61c6e753 upstream.

kzalloc could return NULL. Hence add a check to avoid
NULL pointer dereference.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
[bwh: Backported to 3.2: adjust context and error label]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/dma/pl330.c

@@ -858,6 +858,11 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
 	/* Initialize channel parameters */
 	num_chan = max(pdat ? pdat->nr_valid_peri : 0, (u8)pi->pcfg.num_chan);
 	pdmac->peripherals = kzalloc(num_chan * sizeof(*pch), GFP_KERNEL);
+	if (!pdmac->peripherals) {
+		ret = -ENOMEM;
+		dev_err(&adev->dev, "unable to allocate pdmac->peripherals\n");
+		goto probe_err4;
+	}
 
 	for (i = 0; i < num_chan; i++) {
 		pch = &pdmac->peripherals[i];