Re: [PATCH bpf v2 2/2] fsverity: Fix silent truncation in bpf_get_fsverity_digest()
Song Liu <[email protected]> Mon, 3 Aug 2026 22:41:22 -0700
| Newsgroups | org.kernel.vger.bpf,dev.linux.lists.fsverity,org.kernel.vger.linux-kernel,org.kernel.vger.stable |
|---|---|
| Message-ID | <CAPhsuW5HJbh0LP3FW6-LjYJHvKXYAYuQsvxAX8VuemXS+CAi6A@mail.gmail.com> |
On Mon, Aug 3, 2026 at 11:13=E2=80=AFAM Eric Biggers <[email protected]> = wrote: > > bpf_get_fsverity_digest() silently truncates the digest if the provided > buffer is too small. This is a footgun, and it doesn't match the > semantics of the equivalent UAPI (FS_IOC_MEASURE_VERITY). > > Change it to return -EOVERFLOW instead, matching FS_IOC_MEASURE_VERITY. > > Fixes: 67814c00de31 ("bpf, fsverity: Add kfunc bpf_get_fsverity_digest") > Cc: [email protected] > Signed-off-by: Eric Biggers <[email protected]> Acked-by: Song Liu <[email protected]>