From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue, 5 Dec 2017 14:38:43 +0000 (+0300)
Subject: xen/pvcalls: check for xenbus_read() errors
X-Git-Tag: v4.15-rc3~14^2~1
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=8c71fa88f7778eb093ee22cba13a3813a82113ad;p=linux-block.git

xen/pvcalls: check for xenbus_read() errors

Smatch complains that "len" is uninitialized if xenbus_read() fails so
let's add some error handling.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---

diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
index 40caa92bff33..afa3f1b5d807 100644
--- a/drivers/xen/pvcalls-front.c
+++ b/drivers/xen/pvcalls-front.c
@@ -1128,6 +1128,8 @@ static int pvcalls_front_probe(struct xenbus_device *dev,
 	}
 
 	versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len);
+	if (IS_ERR(versions))
+		return PTR_ERR(versions);
 	if (!len)
 		return -EINVAL;
 	if (strcmp(versions, "1")) {