[PATCH] mmc: bcm2835: Fix possible NULL ptr dereference in bcm2835_request

[Stefan Wahren]

This fixes a NULL pointer dereference in case of a MMC request with a
set block count command and no data.

Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
Signed-off-by: Stefan Wahren <stefan.wahren at i2se.com>
---
 drivers/mmc/host/bcm2835.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
index 7d1b0db..1f343a4 100644
--- a/drivers/mmc/host/bcm2835.c
+++ b/drivers/mmc/host/bcm2835.c
@@ -1200,7 +1200,8 @@ static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq)
 		return;
 	}
 
-	host->use_sbc = !!mrq->sbc && (host->mrq->data->flags & MMC_DATA_READ);
+	host->use_sbc = !!mrq->sbc && host->mrq->data &&
+			(host->mrq->data->flags & MMC_DATA_READ);
 	if (host->use_sbc) {
 		if (bcm2835_send_command(host, mrq->sbc)) {
 			if (!host->use_busy)
-- 
1.7.9.5