Patch "mmc: pxamci: fix potential oops" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

mmc: pxamci: fix potential oops

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mmc-pxamci-fix-potential-oops.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Robert Jarzmik <[email protected]>
Date: Thu, 14 Jul 2016 17:05:50 +0200
Subject: mmc: pxamci: fix potential oops

From: Robert Jarzmik <[email protected]>

commit b3802db5eb72d2a96f4aa4ff0abb937033df2acf upstream.

As reported by Dan in his report in [1], there is a potential NULL pointer derefence if these conditions are met :
- there is no platform_data provided, ie. host->pdata = NULL

Fix this by only using the platform data ro_invert when a gpio for read-only is provided by the platform data.

This doesn't appear yet as every pxa board provides a platform_data, and calls pxa_set_mci_info() with a non NULL pointer.

[1] [bug report] mmc: pxamci: fix card detect with slot-gpio API. The commit fd546ee6a7dc ("mmc: pxamci: fix card detect with slot-gpio API") from Sep 26, 2015, leads to the following static checker warning:

	drivers/mmc/host/pxamci.c:809 pxamci_probe()
	warn: variable dereferenced before check 'host->pdata' (see line 798)

---
 drivers/mmc/host/pxamci.c |   16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

@@ -798,14 +798,16 @@ static int pxamci_probe(struct platform_
 		gpio_direction_output(gpio_power,
 				      host->pdata->gpio_power_invert);
 	}
-	if (gpio_is_valid(gpio_ro))
+	if (gpio_is_valid(gpio_ro)) {
 		ret = mmc_gpio_request_ro(mmc, gpio_ro);
-	if (ret) {
-		dev_err(&pdev->dev, "Failed requesting gpio_ro %d\n", gpio_ro);
-		goto out;
-	} else {
-		mmc->caps2 |= host->pdata->gpio_card_ro_invert ?
-			0 : MMC_CAP2_RO_ACTIVE_HIGH;
+		if (ret) {
+			dev_err(&pdev->dev, "Failed requesting gpio_ro %d\n",
+				gpio_ro);
+			goto out;
+		} else {
+			mmc->caps2 |= host->pdata->gpio_card_ro_invert ?
+				0 : MMC_CAP2_RO_ACTIVE_HIGH;
+		}
 	}
 
 	if (gpio_is_valid(gpio_cd))

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/mmc-pxamci-fix-potential-oops.patch