Date: Fri, 28 Jun 2013 14:54:08 +0100
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Joakim Tjernlund <joakim.tjernlund@transmode.se>
Subject: Re: [PATCH 1/2] UBIFS: prepare to fix a horrid bug
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On Fri, Jun 28, 2013 at 02:27:58PM +0200, Joakim Tjernlund wrote:
> > So here we introduce a local variable 'pos', read 'file->f_pose' once at 
> very
> > the beginning, and then stick to 'pos'. The result of this is that when
> > 'ubifs_dir_llseek()' changes 'file->f_pos' while we are in the middle of
> > 'ubifs_readdir()', the latter "wins".
> 
> Ouch, I hope JFFS2 doesn't have the same bug?

FWIW, this class of bugs (f_pos races, *not* kfree-under-us) is dealt with
by switch to saner API - see commits in linux-next marked [readdir] <something>