From: Jarek Poplawski <jarkao2@o2.pl>
To: netdev@vger.kernel.org
Subject: Re: [PATCH] locking bug in fib_semantics.c
Date: Mon, 21 Aug 2006 10:16:43 +0200 [thread overview]
Message-ID: <20060821081642.GA2637@ff.dom.local> (raw)
In-Reply-To: <20060817093615.GA25553@ms2.inr.ac.ru>
On 17-08-2006 11:36, Alexey Kuznetsov wrote:
> Hello!
>
> [IPV4]: severe locking bug in fib_semantics.c
>
> The patch is for net-2.6.19, but the bug is present in all the kernels
> since yore.
>
> Found in 2.4 by Yixin Pan <yxpan@hotmail.com>. Why do we need lockdep,
> when sharp-sighted eyes are available? :-)
>
>> When I read fib_semantics.c of Linux-2.4.32, write_lock(&fib_info_lock) =
>> is used in fib_release_info() instead of write_lock_bh(&fib_info_lock). =
>> Is the following case possible: a BH interrupts fib_release_info() while =
>> holding the write lock, and calls ip_check_fib_default() which calls =
>> read_lock(&fib_info_lock), and spin forever.
But I hope the real reason for this patch isn't exactly like that.
Could fib_release_info() be interrupted by BH really?
Jarek P.
next prev parent reply other threads:[~2006-08-21 8:13 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-17 9:36 [PATCH] locking bug in fib_semantics.c Alexey Kuznetsov
2006-08-18 1:29 ` David Miller
2006-08-21 8:16 ` Jarek Poplawski [this message]
2006-08-21 8:17 ` David Miller
2006-08-21 11:02 ` Jarek Poplawski
2006-08-22 10:35 ` Jarek Poplawski
2006-08-23 6:34 ` Jarek Poplawski
2006-08-23 18:31 ` Stephen Hemminger
2006-08-24 11:04 ` Jarek Poplawski
2006-08-24 14:18 ` Stephen Hemminger
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=20060821081642.GA2637@ff.dom.local \
--to=jarkao2@o2.pl \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).