linux-kernel - Re: [PATCH -tip] remove the BKL: remove "BKL auto-drop" assumption from ext3

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: <20090426163924.GD6236@elte.hu>
Date:	Sun, 26 Apr 2009 18:39:24 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Alessio Igor Bogani <abogani@...ware.it>
Cc:	Jonathan Corbet <corbet@....net>,
	Frédéric Weisbecker <fweisbec@...il.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH -tip] remove the BKL: remove "BKL auto-drop" assumption
	from ext3_remount()


* Alessio Igor Bogani <abogani@...ware.it> wrote:

> Fix ext3_remount()'s "schedule() drops the BKL automatically" assumption,
> when ext3_mark_recovery_complete(), which can sleep, does not do that it can
> lock up.
> 
> Signed-off-by: Alessio Igor Bogani <abogani@...ware.it>
> ---
>  fs/ext3/super.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/ext3/super.c b/fs/ext3/super.c
> index dc905f9..3fa457a 100644
> --- a/fs/ext3/super.c
> +++ b/fs/ext3/super.c
> @@ -2561,9 +2561,11 @@ static int ext3_remount (struct super_block * sb, int * flags, char * data)
>  			 * We have to unlock super so that we can wait for
>  			 * transactions.
>  			 */
> +			unlock_kernel();
>  			unlock_super(sb);
>  			ext3_mark_recovery_complete(sb, es);
>  			lock_super(sb);
> +			lock_kernel();

Shouldnt this be a conditional-unlock, so that if the remount moves 
away from under the BKL we dont break in this place?

	Ingo
--
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/