[PATCH] ps3-vuart: BUG_ON on null drv before dereferencing it on dev_dbg

Colin King colin.king at canonical.com
Tue Sep 1 20:21:16 AEST 2015

From: Colin Ian King <colin.king at canonical.com>

On the unlikely event that drv is null, the current code will
perform a null pointer dereference with it when printing a dev_dbg
message.  Instead, the BUG_ON check on drv should be performed
before we emit the dev_dbg message.

Signed-off-by: Colin Ian King <colin.king at canonical.com>
 drivers/ps3/ps3-vuart.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/ps3/ps3-vuart.c b/drivers/ps3/ps3-vuart.c
index d6db822..632701a 100644
--- a/drivers/ps3/ps3-vuart.c
+++ b/drivers/ps3/ps3-vuart.c
@@ -1000,12 +1000,11 @@ static int ps3_vuart_probe(struct ps3_system_bus_device *dev)
 	dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
 	drv = ps3_system_bus_dev_to_vuart_drv(dev);
+	BUG_ON(!drv);
 	dev_dbg(&dev->core, "%s:%d: (%s)\n", __func__, __LINE__,
-	BUG_ON(!drv);
 	if (dev->port_number >= PORT_COUNT) {
 		return -EINVAL;

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