linux-kernel - [PATCH 17/36] sysdev: detect multiple driver registrations

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

Message-Id: <1208688366-9252-17-git-send-email-gregkh@suse.de>
Date:	Sun, 20 Apr 2008 03:45:47 -0700
From:	Greg Kroah-Hartman <gregkh@...e.de>
To:	linux-kernel@...r.kernel.org
Cc:	Ben Dooks <ben@...ff.org>, Kay Sievers <kay.sievers@...y.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Greg Kroah-Hartman <gregkh@...e.de>
Subject: [PATCH 17/36] sysdev: detect multiple driver registrations

From: Ben Dooks <ben@...ff.org>

I've just found how easy it is to accidentally register a sysdev_driver for
two different classes.  When this happens, bad things happen as the
sysdev_driver structure keeps has the list entry for the driver
registration.

The following patch makes a WARN_ON() if this happens, although I think
BUG_ON or returning -EAGAIN could also be valid responses to this.

Signed-off-by: Ben Dooks <ben@...ff.org>
Cc: Kay Sievers <kay.sievers@...y.org>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>
---
 drivers/base/sys.c |   16 ++++++++++++++++
 1 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/drivers/base/sys.c b/drivers/base/sys.c
index 8e13fd9..1a06c23 100644
--- a/drivers/base/sys.c
+++ b/drivers/base/sys.c
@@ -167,6 +167,22 @@ int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)
 {
 	int err = 0;
 
+	if (!cls) {
+		printk(KERN_WARNING "sysdev: invalid class passed to "
+			"sysdev_driver_register!\n");
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	/* Check whether this driver has already been added to a class. */
+	if ((drv->entry.next != drv->entry.prev) ||
+	    (drv->entry.next != NULL)) {
+		printk(KERN_WARNING "sysdev: class %s: driver (%p) has already"
+			" been registered to a class, something is wrong, but "
+			"will forge on!\n", cls->name, drv);
+		WARN_ON(1);
+	}
+
 	mutex_lock(&sysdev_drivers_lock);
 	if (cls && kset_get(&cls->kset)) {
 		list_add_tail(&drv->entry, &cls->drivers);
-- 
1.5.4.5

--
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/