4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: weiping zhang <zhangweiping@xxxxxxxxxxxxxxx> [ Upstream commit 623401ee33e42cee64d333877892be8db02951eb ] /sys/class/scsi_disk/0:2:0:0/manage_start_stop can be changed to 0 unexpectly by writing an invalid string. 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 @@ -233,11 +233,15 @@ manage_start_stop_store(struct device *d { struct scsi_disk *sdkp = to_scsi_disk(dev); struct scsi_device *sdp = sdkp->device; + bool v; if (!capable(CAP_SYS_ADMIN)) return -EACCES; - sdp->manage_start_stop = simple_strtoul(buf, NULL, 10); + if (kstrtobool(buf, &v)) + return -EINVAL; + + sdp->manage_start_stop = v; return count; }