linux-kernel - [RESEND PATCH] scsi: shost->async_scan should be protected by mutex

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <aae2bdef-2c21-d97d-43f5-5aff2934e8a9@huawei.com>
Date:   Fri, 13 Oct 2017 14:55:18 +0800
From:   "Ouyangzhaowei (Charles)" <ouyangzhaowei@...wei.com>
To:     Tyrel Datwyler <turtle.in.the.kernel@...il.com>,
        <jejb@...ux.vnet.ibm.com>, <martin.petersen@...cle.com>,
        <linux-kernel@...r.kernel.org>
CC:     <linux-scsi@...r.kernel.org>, Suoben <suoben@...wei.com>,
        "Wulizhen (Pss)" <pss.wulizhen@...wei.com>
Subject: [RESEND PATCH] scsi: shost->async_scan should be protected by
 mutex_lock

shost->async_scan should be protected by mutex_lock, otherwise the check
of "called twice" won't work.

Signed-off-by: Ouyang Zhaowei <ouyangzhaowei@...wei.com>
---
 drivers/scsi/scsi_scan.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index fd88dab..20d539b 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1722,9 +1722,10 @@ static struct async_scan_data
*scsi_prep_async_scan(struct Scsi_Host *shost)
        if (strncmp(scsi_scan_type, "sync", 4) == 0)
                return NULL;

+       mutex_lock(&shost->scan_mutex);
        if (shost->async_scan) {
                shost_printk(KERN_DEBUG, shost, "%s called twice\n",
__func__);
-               return NULL;
+               goto unlock;
        }

        data = kmalloc(sizeof(*data), GFP_KERNEL);
@@ -1735,7 +1736,6 @@ static struct async_scan_data
*scsi_prep_async_scan(struct Scsi_Host *shost)
                goto err;
        init_completion(&data->prev_finished);

-       mutex_lock(&shost->scan_mutex);
        spin_lock_irqsave(shost->host_lock, flags);
        shost->async_scan = 1;
        spin_unlock_irqrestore(shost->host_lock, flags);
@@ -1751,6 +1751,8 @@ static struct async_scan_data
*scsi_prep_async_scan(struct Scsi_Host *shost)

  err:
        kfree(data);
+ unlock:
+       mutex_unlock(&shost->scan_mutex);
        return NULL;
 }