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From:   Tadeusz Struk <tadeusz.struk@linaro.org>
To:     linux-scsi@vger.kernel.org
Cc:     Tadeusz Struk <tadeusz.struk@linaro.org>,
        Bart Van Assche <bvanassche@acm.org>,
        Christoph Hellwig <hch@lst.de>,
        "James E . J . Bottomley" <jejb@linux.ibm.com>,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: [PATCH 1/2] scsi: scsi_ioctl: Validate command size
Date:   Tue,  2 Nov 2021 17:37:18 -0700
Message-Id: <20211103003719.1041490-1-tadeusz.struk@linaro.org>
MIME-Version: 1.0
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Need to make sure the command size before copying the
command from user.

Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: James E.J. Bottomley <jejb@linux.ibm.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: <linux-scsi@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Cc: <stable@vger.kernel.org> # 5.15, 5.14, 5.10
Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org>
---
 drivers/scsi/scsi_ioctl.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/scsi/scsi_ioctl.c b/drivers/scsi/scsi_ioctl.c
index 6ff2207bd45a..58c1f62aca68 100644
--- a/drivers/scsi/scsi_ioctl.c
+++ b/drivers/scsi/scsi_ioctl.c
@@ -347,6 +347,8 @@ static int scsi_fill_sghdr_rq(struct scsi_device *sdev, struct request *rq,
 {
 	struct scsi_request *req = scsi_req(rq);
 
+	if (hdr->cmd_len < 6 || hdr->cmd_len > sizeof(req->__cmd))
+		return -EMSGSIZE;
 	if (copy_from_user(req->cmd, hdr->cmdp, hdr->cmd_len))
 		return -EFAULT;
 	if (!scsi_cmd_allowed(req->cmd, mode))
-- 
2.31.1