scsi: sd: add check for changing allow_restart

/sys/class/scsi_disk/0:2:0:0/allow_restart can be changed to 0 unexpectly by writing invalid string, like following:

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

Signed-off-by weiping zhang <[email protected]>

---
 drivers/scsi/sd.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

drivers/scsi/sd.c +6 -1

index 3ef2214..d18639f 100644
@@ -253,6 +253,7 @@ static ssize_t
 allow_restart_store(struct device *dev, struct device_attribute *attr,
 		    const char *buf, size_t count)
 {
+	int err, v;
 	struct scsi_disk *sdkp = to_scsi_disk(dev);
 	struct scsi_device *sdp = sdkp->device;
 

@@ -262,7 +263,11 @@ allow_restart_store(struct device *dev, struct device_attribute *attr,
 	if (sdp->type != TYPE_DISK && sdp->type != TYPE_ZBC)
 		return -EINVAL;
 
-	sdp->allow_restart = simple_strtoul(buf, NULL, 10);
+	err = kstrtoint(buf, 10, &v);
+	if (err || (v != 0 && v != 1))
+		return -EINVAL;
+
+	sdp->allow_restart = v;
 
 	return count;
 }

Signature · 1 line

2.9.4

/sys/class/scsi_disk/0:2:0:0/allow_restart can be changed to 0 unexpectly by writing invalid string, like following:

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

weiping,

Quoted 4 lines

/sys/class/scsi_disk/0:2:0:0/allow_restart can be changed to 0 unexpectly by writing invalid string, like following:

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

Please switch to kstrtobool() and fix up manage_start_stop as well.

Thanks!