From mboxrd@z Thu Jan 1 00:00:00 1970 From: weiping zhang Subject: [PATCH] scsi: sd: add check for changing allow_restart Date: Thu, 28 Sep 2017 00:53:18 +0800 Message-ID: <20170927165313.GA36250@localhost.didichuxing.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Received: from 22.17.110.36.static.bjtelecom.net ([36.110.17.22]:29247 "EHLO BJEXCAS002.didichuxing.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751163AbdI0Qxb (ORCPT ); Wed, 27 Sep 2017 12:53:31 -0400 Content-Disposition: inline Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: martin.petersen@oracle.com, jejb@linux.vnet.ibm.com Cc: linux-scsi@vger.kernel.org /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 --- drivers/scsi/sd.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 3ef2214..d18639f 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -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; } -- 2.9.4