All of lore.kernel.org
 help / color / mirror / Atom feed
From: Oliver Hartkopp <socketcan@hartkopp.net>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>,
	Linux Netdev List <netdev@vger.kernel.org>
Subject: Re: [PATCH] can: should not use __dev_get_by_index() without locks
Date: Fri, 06 Nov 2009 12:04:16 +0100	[thread overview]
Message-ID: <4AF402B0.7090202@hartkopp.net> (raw)
In-Reply-To: <4AF3F905.4030608@gmail.com>

Eric Dumazet wrote:
> David
> 
> A more elegant patch will be possible for 2.6.33, but for 2.6.32,
> I think following patch is needed (Please note I did not test it)
> 
> (More elegant : use RCU lookups ;) , I'll wait for net-next-2.6 
>  upgrade as well)
> 
> Thanks
> 
> [PATCH] can: should not use __dev_get_by_index() without locks
> 
> bcm_proc_getifname() is called with RTNL and dev_base_lock
> not held. It calls __dev_get_by_index() without locks, and
> this is illegal (might crash)
> 
> Close the race by holding dev_base_lock and copying dev->name
> in the protected section.
> 
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>

Thanks for pointing this out.
This is a quite old code section which is not used very often at runtime - and
usually the netdevice is not removed at that time ;-)

Btw. this is no excuse for that missing locking, sorry.

Thanks for the fix!

Compiled and tested successfully.

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>



  reply	other threads:[~2009-11-06 11:04 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-11-06 10:23 [PATCH] can: should not use __dev_get_by_index() without locks Eric Dumazet
2009-11-06 11:04 ` Oliver Hartkopp [this message]
2009-11-08  8:34   ` David Miller

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4AF402B0.7090202@hartkopp.net \
    --to=socketcan@hartkopp.net \
    --cc=davem@davemloft.net \
    --cc=eric.dumazet@gmail.com \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.