linux-kernel - [PATCH] crypto: lib/sha256

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Message-ID: <aCcmJGuCnuyHmHbx@gondor.apana.org.au>
Date: Fri, 16 May 2025 19:48:52 +0800
From: Herbert Xu <herbert@...dor.apana.org.au>
To: Borislav Petkov <bp@...en8.de>
Cc: Jain@...menos.rohan.me.apana.org.au, Ayush <Ayush.Jain3@....com>,
	Stephen Rothwell <sfr@...b.auug.org.au>, x86-ml <x86@...nel.org>,
	lkml <linux-kernel@...r.kernel.org>, linux-crypto@...r.kernel.org,
	Eric Biggers <ebiggers@...gle.com>
Subject: [PATCH] crypto: lib/sha256 - Disable SIMD

On Fri, May 16, 2025 at 07:34:06PM +0800, Herbert Xu wrote:
> 
> So what's happened is that previously if you call sha256_update
> from lib/crypto it would only use the generic C code to perform
> the operation.
> 
> This has now been changed to automatically use SIMD instructions
> which obviously blew up in your case.

In the interim you can go back to the old ways and disable SIMD
for lib/crypto sha256 with this patch:

---8<---
Disable SIMD usage in lib/crypto sha256 as it is causing crashes.

Reported-by: Borislav Petkov <bp@...en8.de>
Fixes: 950e5c84118c ("crypto: sha256 - support arch-optimized lib and expose through shash")
Signed-off-by: Herbert Xu <herbert@...dor.apana.org.au>

diff --git a/include/crypto/internal/sha2.h b/include/crypto/internal/sha2.h
index b9bccd3ff57f..e1b0308c0539 100644
--- a/include/crypto/internal/sha2.h
+++ b/include/crypto/internal/sha2.h
@@ -32,7 +32,7 @@ static inline void sha256_choose_blocks(
 	if (!IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_SHA256) || force_generic)
 		sha256_blocks_generic(state, data, nblocks);
 	else if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_SHA256_SIMD) &&
-		 (force_simd || crypto_simd_usable()))
+		 force_simd)
 		sha256_blocks_simd(state, data, nblocks);
 	else
 		sha256_blocks_arch(state, data, nblocks);
-- 
Email: Herbert Xu <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt