From: Eric Biggers <ebiggers@kernel.org>
To: Yichong Chen <chenyichong@uniontech.com>
Cc: tytso@mit.edu, ast@kernel.org, song@kernel.org,
fsverity@lists.linux.dev, bpf@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] fsverity: reject short BPF digest buffers
Date: Wed, 5 Aug 2026 12:50:13 -0700 [thread overview]
Message-ID: <20260805195013.GD3438@quark> (raw)
In-Reply-To: <20260805075655.950308-1-chenyichong@uniontech.com>
On Wed, Aug 05, 2026 at 03:56:55PM +0800, Yichong Chen wrote:
> bpf_get_fsverity_digest() reports the digest size as the full hash digest
> size. However, when the provided dynptr only has room for part of the
> digest, the helper currently copies the truncated digest and still returns
> success.
>
> Returning success with a digest_size that is larger than the actual copied
> digest is misleading for integrity policy code. Match the ioctl
> measurement path and reject too-small output buffers with -EOVERFLOW.
>
> Fixes: 67814c00de31 ("bpf, fsverity: Add kfunc bpf_get_fsverity_digest")
> Signed-off-by: Yichong Chen <chenyichong@uniontech.com>
> ---
> fs/verity/measure.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
Already handled by https://lore.kernel.org/bpf/20260803181232.14743-1-ebiggers@kernel.org/
- Eric
prev parent reply other threads:[~2026-08-05 19:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-05 7:56 [PATCH] fsverity: reject short BPF digest buffers Yichong Chen
2026-08-05 8:07 ` sashiko-bot
2026-08-05 19:50 ` Eric Biggers [this message]
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