From: Colin Ian King <colin.king@canonical.com>
Date: Tue, 2 Jan 2018 17:54:19 +0000 (+0000)
Subject: slimbus: avoid null pointer dereference on msg
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7dde60c06cff611b9f88676ef9e67365dc77b19a;p=linux.git

slimbus: avoid null pointer dereference on msg

The pointer msg is checked to see if it is null at the start of
the function and jumps to the error exit label reterr that then
dereferences msg when it prints a dev_err error message. Avoid
this potential null pointer dereference by only printing the
error message if msg is not null.

Detected by CoverityScan, CID#1463141 ("Dereference after null check")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/slimbus/messaging.c b/drivers/slimbus/messaging.c
index 755462a4c75e4..8b2c77f516b95 100644
--- a/drivers/slimbus/messaging.c
+++ b/drivers/slimbus/messaging.c
@@ -170,8 +170,9 @@ static int slim_val_inf_sanity(struct slim_controller *ctrl,
 		break;
 	}
 reterr:
-	dev_err(ctrl->dev, "Sanity check failed:msg:offset:0x%x, mc:%d\n",
-		msg->start_offset, mc);
+	if (msg)
+		dev_err(ctrl->dev, "Sanity check failed:msg:offset:0x%x, mc:%d\n",
+			msg->start_offset, mc);
 	return -EINVAL;
 }