linux-ext4 - journal forget may introduce buffer aliasing problem?

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 27 Jan 2010 11:44:08 +0800
From:	丁定华 <dingdinghua85@...il.com>
To:	linux-ext4@...r.kernel.org
Cc:	Jan Kara <jack@...e.cz>
Subject: journal forget may introduce buffer aliasing problem?

Hi all:
       The following is my analysis(if wrong, please point it out),
may be I can send a patch out if it's a bug.
       If buffer_head belongs to comitting transaction,
jbd2_journal_forget do nothing except discard it from running
transaction. So this buffer will happily be inserted
into committing_transaction's checkpoint list and do write-back work,
then this buffer may be re-used as data-block, then there are two
buffer_heads maps to the same block, buffer aliasing occurs, and we
can't control the writeback order of the two buffer heads, fs may be
inconsistent.
      The same thing will happen if buffer_head doesn't belongs to
running or committing transaction, but lays in checkpoint list.

-- 
丁定华
--
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