SCSI: fix race in device_create

There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.

This patch fixes the problem by using the new function,
device_create_drvdata().  It fixes the problem in all of the scsi
drivers that need it.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index c9d7f721b9e2..ea0edd1b2e76 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1441,17 +1441,18 @@ sg_add(struct device *cl_dev, struct class_interface *cl_intf)
         if (sg_sysfs_valid) {
                 struct device *sg_class_member;
 
-                sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
-                                                MKDEV(SCSI_GENERIC_MAJOR,
-                                                      sdp->index),
-                                                "%s", disk->disk_name);
+                sg_class_member = device_create_drvdata(sg_sysfs_class,
+                                                        cl_dev->parent,
+                                                        MKDEV(SCSI_GENERIC_MAJOR,
+                                                              sdp->index),
+                                                        sdp,
+                                                        "%s", disk->disk_name);
                 if (IS_ERR(sg_class_member)) {
                         printk(KERN_ERR "sg_add: "
                                "device_create failed\n");
                         error = PTR_ERR(sg_class_member);
                         goto cdev_add_err;
                 }
-                dev_set_drvdata(sg_class_member, sdp);
                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
                                           &sg_class_member->kobj, "generic");
                 if (error)