From: Eric Biggers <ebiggers@google.com>
To: Richard Weinberger <richard@nod.at>
Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
linux-fscrypt@vger.kernel.org, david@sigma-star.at,
David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Subject: Re: [PATCH] ubifs: Return -ENOKEY from rename if encryption keys are missing
Date: Tue, 25 Apr 2017 10:54:42 -0700 [thread overview]
Message-ID: <20170425175442.GB41477@google.com> (raw)
In-Reply-To: <1493070381-20075-1-git-send-email-richard@nod.at>
Hi David and Richard,
On Mon, Apr 24, 2017 at 11:46:21PM +0200, Richard Weinberger wrote:
> From: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
>
> If either source or destination directory is encrypted and the
> encryption key is unknown, make sure we return -ENOKEY instead
> of -EPERM, similar to how this case is handled in ext4.
>
> Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
> Signed-off-by: Richard Weinberger <richard@nod.at>
>
> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
> index ff77a0aa2f2b..c342f23581d2 100644
> --- a/fs/ubifs/dir.c
> +++ b/fs/ubifs/dir.c
> @@ -1340,6 +1340,12 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
> if (unlink)
> ubifs_assert(inode_is_locked(new_inode));
>
> + if ((ubifs_crypt_is_encrypted(old_dir) &&
> + !fscrypt_has_encryption_key(old_dir)) ||
> + (ubifs_crypt_is_encrypted(new_dir) &&
> + !fscrypt_has_encryption_key(new_dir)))
> + return -ENOKEY;
> +
> if (old_dir != new_dir) {
> if (ubifs_crypt_is_encrypted(new_dir) &&
> !fscrypt_has_permitted_context(new_dir, old_inode))
> @@ -1564,6 +1570,12 @@ static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
>
> ubifs_assert(fst_inode && snd_inode);
>
> + if ((ubifs_crypt_is_encrypted(old_dir) &&
> + !fscrypt_has_encryption_key(old_dir)) ||
> + (ubifs_crypt_is_encrypted(new_dir) &&
> + !fscrypt_has_encryption_key(new_dir)))
> + return -ENOKEY;
> +
> if ((ubifs_crypt_is_encrypted(old_dir) ||
> ubifs_crypt_is_encrypted(new_dir)) &&
> (old_dir != new_dir) &&
> --
Did you test that this change actually does anything? Unlike ext4 and f2fs,
ubifs calls fscrypt_setup_filename() from its rename methods rather than through
a helper function ${FS}_find_entry(). Therefore it's able to pass in lookup=0,
which means that the key is required. So it should already be failing with
ENOKEY. You can verify this by running xfstests generic/419.
- Eric
next prev parent reply other threads:[~2017-04-25 17:55 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-24 21:46 [PATCH] ubifs: Return -ENOKEY from rename if encryption keys are missing Richard Weinberger
2017-04-25 17:54 ` Eric Biggers [this message]
2017-04-26 11:48 ` David Oberhollenzer
2017-04-26 22:52 ` Eric Biggers
2017-04-27 8:59 ` David Oberhollenzer
2017-04-27 19:34 ` Eric Biggers
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