4.4-stable review patch. If anyone has any objections, please let me know.
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From: weiping zhang zhangweiping@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 zhangweiping@didichuxing.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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; }