From: James Bottomley <jejb@linux.ibm.com>
Date: Sat, 28 Nov 2020 15:27:21 -0800
Subject: scsi: ses: Don't attach if enclosure has no components
Git-commit: 3fe97ff3d94934649abb0652028dd7296170c8d0
Patch-mainline: v6.3-rc1
References: git-fixes

An enclosure with no components can't usefully be operated by the driver
(since effectively it has nothing to manage), so report the problem and
don't attach. Not attaching also fixes an oops which could occur if the
driver tries to manage a zero component enclosure.

[mkp: Switched to KERN_WARNING since this scenario is common]

Link: https://lore.kernel.org/r/c5deac044ac409e32d9ad9968ce0dcbc996bfc7a.camel@linux.ibm.com
Cc: stable@vger.kernel.org
Reported-by: Ding Hui <dinghui@sangfor.com.cn>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Lee Duncan <lduncan@suse.com>
---
 drivers/scsi/ses.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/scsi/ses.c b/drivers/scsi/ses.c
index 9d4fb09acc1e..b11a9162e73a 100644
--- a/drivers/scsi/ses.c
+++ b/drivers/scsi/ses.c
@@ -733,6 +733,12 @@ static int ses_intf_add(struct device *cdev,
 		    type_ptr[0] == ENCLOSURE_COMPONENT_ARRAY_DEVICE)
 			components += type_ptr[1];
 	}
+
+	if (components == 0) {
+		sdev_printk(KERN_WARNING, sdev, "enclosure has no enumerated components\n");
+		goto err_free;
+	}
+
 	ses_dev->page1 = buf;
 	ses_dev->page1_len = len;
 	buf = NULL;