linux-kernel - get_device in device_create

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>] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 1 Aug 2006 13:25:09 -0700
From:	Pete Zaitcev <zaitcev@...hat.com>
To:	greg@...ah.com
Cc:	linux-kernel@...r.kernel.org
Subject: get_device in device_create_file

Hi, Greg:

This code makes no sense to me:

> int device_create_file(struct device * dev, struct device_attribute * attr)
> {
> 	int error = 0;
> 	if (get_device(dev)) {
> 		error = sysfs_create_file(&dev->kobj, &attr->attr);
> 		put_device(dev);
> 	}
> 	return error;
> }

If the struct device *dev, and its presumably enclosing structure,
can be freed by a different CPU (or pre-empt), then get_device
does not protect it. It can be freed before get_device is reached.
Buf it not, and the caller has a reference, then the call to
get_device is redundant.

How is this supposed to work?

-- Pete
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/