Re: [PATCH v5 4/6] ubifs: don't trigger assertion on invalid no-key filename

From: Eric Biggers <ebiggers@kernel.org>
To: Richard Weinberger <richard@nod.at>, linux-mtd@lists.infradead.org
Cc: Daniel Rosenberg <drosen@google.com>,
	Gabriel Krisman Bertazi <krisman@collabora.com>,
	linux-kernel@vger.kernel.org,
	linux-f2fs-devel@lists.sourceforge.net,
	linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-ext4@vger.kernel.org, kernel-team@android.com
Subject: Re: [PATCH v5 4/6] ubifs: don't trigger assertion on invalid no-key filename
Date: Fri, 24 Jan 2020 12:14:02 -0800	[thread overview]
Message-ID: <20200124201317.GC41762@gmail.com> (raw)
In-Reply-To: <20200122003014.GA180824@gmail.com>

On Tue, Jan 21, 2020 at 04:30:15PM -0800, Eric Biggers wrote:
> On Mon, Jan 20, 2020 at 02:31:59PM -0800, Eric Biggers wrote:
> > From: Eric Biggers <ebiggers@google.com>
> > 
> > If userspace provides an invalid fscrypt no-key filename which encodes a
> > hash value with any of the UBIFS node type bits set (i.e. the high 3
> > bits), gracefully report ENOENT rather than triggering ubifs_assert().
> > 
> > Test case with kvm-xfstests shell:
> > 
> >     . fs/ubifs/config
> >     . ~/xfstests/common/encrypt
> >     dev=$(__blkdev_to_ubi_volume /dev/vdc)
> >     ubiupdatevol $dev -t
> >     mount $dev /mnt -t ubifs
> >     mkdir /mnt/edir
> >     xfs_io -c set_encpolicy /mnt/edir
> >     rm /mnt/edir/_,,,,,DAAAAAAAAAAAAAAAAAAAAAAAAAA
> > 
> > With the bug, the following assertion fails on the 'rm' command:
> > 
> >     [   19.066048] UBIFS error (ubi0:0 pid 379): ubifs_assert_failed: UBIFS assert failed: !(hash & ~UBIFS_S_KEY_HASH_MASK), in fs/ubifs/key.h:170
> > 
> > Fixes: f4f61d2cc6d8 ("ubifs: Implement encrypted filenames")
> > Cc: <stable@vger.kernel.org> # v4.10+
> > Signed-off-by: Eric Biggers <ebiggers@google.com>
> 
> Richard, can you review the two UBIFS patches in this series, and if you're okay
> with them, provide Acked-by's so that we can take them through the fscrypt tree?
> They don't conflict with anything currently in the UBIFS tree.
> 

Richard, any objection to us taking these patches through the fscrypt tree?

- Eric