From: Eric Biggers <ebiggers@kernel.org>
To: Alexander Larsson <alexl@redhat.com>
Cc: miklos@szeredi.hu, linux-unionfs@vger.kernel.org,
amir73il@gmail.com, tytso@mit.edu, fsverity@lists.linux.dev
Subject: Re: [PATCH v2 5/6] ovl: Validate verity xattr when resolving lowerdata
Date: Sun, 14 May 2023 12:16:47 -0700 [thread overview]
Message-ID: <20230514191647.GD9528@sol.localdomain> (raw)
In-Reply-To: <b58e57955e122b5d6c4e087cf2dd6ed664152c7b.1683102959.git.alexl@redhat.com>
On Wed, May 03, 2023 at 10:51:38AM +0200, Alexander Larsson wrote:
> When resolving lowerdata (lazily or non-lazily) we check the
> overlay.verity xattr on the metadata inode, and if set verify that the
> source lowerdata inode matches it (according to the verity options
> enabled).
Keep in mind that the lifetime of an inode's fsverity digest is from when it is
first opened to when the inode is evicted from the inode cache.
If the inode gets evicted from cache and re-instantiated, it could have been
arbitrarily changed.
Given that, does this verification happen in the right place? I would have
expected it to happen whenever the file is opened, but it seems you do it when
the dentry is looked up instead. Maybe that works too, but I'd appreciate an
explanation.
- Eric
next prev parent reply other threads:[~2023-05-14 19:16 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-03 8:51 [PATCH v2 0/6] ovl: Add support for fs-verity checking of lowerdata Alexander Larsson
2023-05-03 8:51 ` [PATCH v2 1/6] fsverity: Export fsverity_get_digest Alexander Larsson
2023-05-03 8:51 ` [PATCH v2 2/6] ovl: Break out ovl_e_path_real() from ovl_i_path_real() Alexander Larsson
2023-05-03 8:51 ` [PATCH v2 3/6] ovl: Break out ovl_e_path_lowerdata() from ovl_path_lowerdata() Alexander Larsson
2023-05-03 8:51 ` [PATCH v2 4/6] ovl: Add framework for verity support Alexander Larsson
2023-05-03 11:51 ` Amir Goldstein
2023-05-14 19:22 ` Eric Biggers
2023-05-15 5:44 ` Alexander Larsson
2023-05-15 6:00 ` Eric Biggers
2023-05-15 6:46 ` Alexander Larsson
2023-05-03 8:51 ` [PATCH v2 5/6] ovl: Validate verity xattr when resolving lowerdata Alexander Larsson
2023-05-03 15:35 ` Amir Goldstein
2023-05-14 19:16 ` Eric Biggers [this message]
2023-05-14 21:00 ` Amir Goldstein
2023-05-15 6:14 ` Alexander Larsson
2023-06-09 13:03 ` Amir Goldstein
2023-06-10 15:02 ` Alexander Larsson
2023-06-11 11:20 ` Amir Goldstein
2023-06-12 10:32 ` Alexander Larsson
2023-06-16 5:07 ` Amir Goldstein
2023-06-16 5:24 ` Eric Biggers
2023-06-16 5:55 ` Amir Goldstein
2023-06-16 7:50 ` Alexander Larsson
2023-06-16 8:12 ` Amir Goldstein
2023-06-16 8:39 ` Alexander Larsson
2023-06-16 9:27 ` Amir Goldstein
2023-06-16 11:33 ` Alexander Larsson
2023-06-16 12:24 ` Amir Goldstein
2023-06-16 12:28 ` Miklos Szeredi
2023-06-16 13:14 ` Gao Xiang
2023-05-15 6:12 ` Alexander Larsson
2023-05-03 8:51 ` [PATCH v2 6/6] ovl: Handle verity during copy-up Alexander Larsson
2023-05-03 15:33 ` Amir Goldstein
2023-05-14 19:09 ` [PATCH v2 0/6] ovl: Add support for fs-verity checking of lowerdata Eric Biggers
2023-05-14 21:25 ` Amir Goldstein
2023-05-14 22:19 ` Gao Xiang
2023-05-15 5:55 ` Alexander Larsson
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