4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: weiping zhang <zhangweiping@xxxxxxxxxxxxxxx>
[ 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 <zhangweiping@xxxxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/sd.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -259,6 +259,7 @@ 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;
@@ -268,7 +269,10 @@ allow_restart_store(struct device *dev,
if (sdp->type != TYPE_DISK)
return -EINVAL;
- sdp->allow_restart = simple_strtoul(buf, NULL, 10);
+ if (kstrtobool(buf, &v))
+ return -EINVAL;
+
+ sdp->allow_restart = v;
return count;
}