[PATCH 4.14 158/178] scsi: sd: change allow_restart to bool in sysfs interface

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: weiping zhang <zhangweip...@didichuxing.com>


[ Upstream commit 658e9a6dc1126f21fa417cd213e1cdbff8be0ba2 ]

/sys/class/scsi_disk/0:2:0:0/allow_restart can be changed to 0
unexpectedly by writing an invalid string such as the following:

echo asdf > /sys/class/scsi_disk/0:2:0:0/allow_restart

Signed-off-by: weiping zhang <zhangweip...@didichuxing.com>
Signed-off-by: Martin K. Petersen <martin.peter...@oracle.com>
Signed-off-by: Sasha Levin <alexander.le...@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/scsi/sd.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -257,6 +257,7 @@ static ssize_t
 allow_restart_store(struct device *dev, struct device_attribute *attr,
                    const char *buf, size_t count)
 {
+       bool v;
        struct scsi_disk *sdkp = to_scsi_disk(dev);
        struct scsi_device *sdp = sdkp->device;
 
@@ -266,7 +267,10 @@ allow_restart_store(struct device *dev,
        if (sdp->type != TYPE_DISK && sdp->type != TYPE_ZBC)
                return -EINVAL;
 
-       sdp->allow_restart = simple_strtoul(buf, NULL, 10);
+       if (kstrtobool(buf, &v))
+               return -EINVAL;
+
+       sdp->allow_restart = v;
 
        return count;
 }