linux-ext4 - Re: [PATCH] jbd2: correctly unescape journal data blocks

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, 17 Mar 2008 16:38:54 +0100
From:	Jan Kara <jack@...e.cz>
To:	Duane Griffin <duaneg@...da.com>
Cc:	sct@...hat.com, akpm@...ux-foundation.org,
	linux-ext4@...r.kernel.org
Subject: Re: [PATCH] jbd2: correctly unescape journal data blocks

> Fix a long-standing typo (predating git) that will cause data corruption if a
> journal data block needs unescaping. At the moment the wrong buffer head's data
> is being unescaped.
> 
> To test this case mount a filesystem with data=journal, start creating and
> deleting a bunch of files containing only JBD2_MAGIC_NUMBER (0xc03b3998), then
> pull the plug on the device. Without this patch the files will contain zeros
> instead of the correct data after recovery.
> 
> Signed-off-by: Duane Griffin <duaneg@...da.com>
> ---
>  fs/jbd2/recovery.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
> index 1464113..5d0405a 100644
> --- a/fs/jbd2/recovery.c
> +++ b/fs/jbd2/recovery.c
> @@ -535,7 +535,7 @@ static int do_one_pass(journal_t *journal,
>  					memcpy(nbh->b_data, obh->b_data,
>  							journal->j_blocksize);
>  					if (flags & JBD2_FLAG_ESCAPE) {
> -						*((__be32 *)bh->b_data) =
> +						*((__be32 *)nbh->b_data) =
>  						cpu_to_be32(JBD2_MAGIC_NUMBER);
>  					}
  Acked-by: Jan Kara <jack@...e.cz>

									Honza
-- 
Jan Kara <jack@...e.cz>
SuSE CR Labs
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html