[PATCH] ubifs: replay: Detect and kill orphaned xattrs

[Richard Weinberger]

Am Montag, 9. Oktober 2017, 15:49:56 CEST schrieb Marc Kleine-Budde:
> On 06/26/2017 01:19 PM, Richard Weinberger wrote:
> > Creating an xattr is an independent journal transaction and the xattr
> > code assumes that there is always a valid host inode present when a new
> > xattr is created. This assumption is not correct for LSM and now
> > fscrypt, for these users UBIFS creates the xattr before the host inode
> > is created and visible to the user. Since these are two journal
> > transactions it can happen that due to a power-cut only the xattr is
> > present but not the host inode nor the directory entry for it. As result
> > of this UBIFS will lose free space and can run out of space at some
> > time.
> > It is also not possible to create the xattr after the host inode because
> > this would violate LSM and fscrypt model. After a power-cut we could end
> > up with a inode without security context.
> > 
> > This is an intermediate fix that can go into -stable, as long term
> > solution we have to make sure that creating the xattr and the host inode
> > is a single journal transaction. But to achieve this the journal code
> > need some rework first.
> > 
> > Cc: Subodh Nijsure <snijsure at grid-net.com>
> > Cc: Marc Kleine-Budde <mkl at pengutronix.de>
> > Cc: Ben Shelton <ben.shelton at ni.com>
> > Cc: Brad Mouring <brad.mouring at ni.com>
> > Cc: Terry Wilcox <terry.wilcox at ni.com>
> > Cc: Gratian Crisan <gratian.crisan at ni.com>
> > Cc: stable at vger.kernel.org
> > Fixes: d7f0b70d30ff ("UBIFS: Add security.* XATTR support for the UBIFS")
> > Signed-off-by: Richard Weinberger <richard at nod.at>
> 
> What happended to this patch? It's not on mainline (and thus not on the
> stable branches). Was there a better fix?

Since the patch is non-trivial I hoped to get a review or tested-by.
Therefore I didn't merge it so far.

Thanks,
//richard