On Fri, Jun 27, 2025 at 11:56:49AM -0700, Eric Biggers wrote:
> Commit 88c02b3f79a6 ("s390/sha3: Support sha3 performance enhancements")
> added the field s390_sha_ctx::first_message_part and made it be used by
> s390_sha_update_blocks(). At the time, s390_sha_update_blocks() was
> used by all the s390 SHA-1, SHA-2, and SHA-3 algorithms. However, only
> the initialization functions for SHA-3 were updated, leaving SHA-1 and
> SHA-2 using first_message_part uninitialized.
>
> This could cause e.g. CPACF_KIMD_SHA_512 | CPACF_KIMD_NIP to be used
> instead of just CPACF_KIMD_NIP. It's unclear why this didn't cause a
> problem earlier; this bug was found only when UBSAN detected the
> uninitialized boolean. Perhaps the CPU ignores CPACF_KIMD_NIP for SHA-1
> and SHA-2. Regardless, let's fix this. For now just initialize to
> false, i.e. don't try to "optimize" the SHA state initialization.
>
> Note: in 6.16, we need to patch SHA-1, SHA-384, and SHA-512. In 6.15
> and earlier, we'll also need to patch SHA-224 and SHA-256, as they
> hadn't yet been librarified (which incidentally fixed this bug).
>
> Fixes: 88c02b3f79a6 ("s390/sha3: Support sha3 performance enhancements")
> Cc: stable@xxxxxxxxxxxxxxx
> Reported-by: Ingo Franzki <ifranzki@xxxxxxxxxxxxx>
> Closes: https://lore.kernel.org/r/12740696-595c-4604-873e-aefe8b405fbf@xxxxxxxxxxxxx
> Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
> ---
>
> This is targeting 6.16. I'd prefer to take this through
> libcrypto-fixes, since the librarification work is also touching this
> area. But let me know if there's a preference for the crypto tree or
> the s390 tree instead.
Applied to https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux.git/log/?h=libcrypto-fixes
- Eric
