netdev - Re: [PATCH] net: Fix userspace RTM

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]

Date:	Mon, 14 Dec 2009 03:05:36 +0100
From:	Marcel Holtmann <marcel@...tmann.org>
To:	"Eric W. Biederman" <ebiederm@...ssion.com>
Cc:	David Miller <davem@...emloft.net>, netdev@...r.kernel.org,
	stable@...nel.org
Subject: Re: [PATCH] net: Fix userspace RTM_NEWLINK notifications.

Hi Eric,

> I received some bug reports about userspace programs having problems
> because after RTM_NEWLINK was received they could not immediate access
> files under /proc/sys/net/ because they had not been registered yet.
> 
> The original problem was trivially fixed by moving the userspace
> notification from rtnetlink_event() to the end of
> register_netdevice().
> 
> When testing that change I discovered I was still getting RTM_NEWLINK
> events before I could access proc and I was also getting RTM_NEWLINK
> events after I was seeing RTM_DELLINK.  Things practically guaranteed
> to confuse userspace.
> 
> After a little more investigation these extra notifications proved to
> be from the new notifiers NETDEV_POST_INIT and NETDEV_UNREGISTER_BATCH
> hitting the default case in rtnetlink_event, and triggering
> unnecessary RTM_NEWLINK messages.
> 
> rtnetlink_event now explicitly handles NETDEV_UNREGISTER_BATCH and
> NETDEV_POST_INIT to avoid sending the incorrect userspace
> notifications.

the POST_INIT and UNREGISTER_BATCH are not 2.6.32 features. They are
2.6.33 features and thus you need to create a separate patch for -stable
if you wanna fix the /proc access issue.

Regards

Marcel


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html