From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 224BDCCF9E3 for ; Tue, 4 Nov 2025 17:39:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=7xYqpK7gk35tODd0h5yiaeI/qICBJPOlqhRGit3KyAY=; b=gC4okyw0E2SxiSbMosZlhnLYh+ Mc4XxwdWmH6M1DIfriHI65F/glTxKwONJmLrowGolT5wAXT2+hFSmuorfsLtTxbkw6DfDRuQCvfZR 2Xdve3y7h/6WwhogRd950YhZB8LaGxcCIyqdejCUWt9G3cIk1A9sEfDn5hzb2Jg23M6NKvwbhcKKJ 39ZGHlNL76VYxMt/mg7Ev/Ufx9/fteMlIVyPKmWgSbPSeaD1aN2j0dNoxr43Muw4+li45xdSK8ebT 9oEdI79ilpCt3P5s4ziU0Gua5jOYCt0Liu8idZwv3Sa52A9+9M7KWEqHLipfzf+GCNx2ZlHO5N53O 0+SjtCmg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vGL0G-0000000CI0A-32Qp; Tue, 04 Nov 2025 17:39:32 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vGL0F-0000000CI01-0w4h for linux-arm-kernel@lists.infradead.org; Tue, 04 Nov 2025 17:39:31 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 9C8B9601EC; Tue, 4 Nov 2025 17:39:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 14414C4CEF7; Tue, 4 Nov 2025 17:39:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762277970; bh=dFzXmIcBVlOGJZ/dA9ocxVm/GMTXIf6nZ4evM0sDxuA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=os7nvEy1/d3dzd2cJwR05Bti4sEOxgANxbGmOd9Yx2rsUDSsFAQ+qsZjTzAhbTaVP nY1NXejKptIuqUc0mdWD68OjE667k55JI0s83nphDygfBrlUb8P93QJ8LOMK6HyCCh xnLS0q2bEMpVIQFRWhlTkmJ9q0YCySOsLr/I3frvkerAp0h12MzExYtQoIGtUVzzHX 3HPpNjZSua69NZswC6eUjOTFDkoNSmPceETGRkgZECW0U0p+AMGXiDahJBQgsB68IO FY9g1Uj2zVJyh4CrdkPrG7hzEEmzVdLfUHB/ELA7QHN1IMvDfNr3+CPiauXanXFasN 2fAdfYr/a97XQ== Date: Tue, 4 Nov 2025 09:37:49 -0800 From: Eric Biggers To: linux-crypto@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Ard Biesheuvel , "Jason A . Donenfeld" , Herbert Xu , linux-arm-kernel@lists.infradead.org, stable@vger.kernel.org Subject: Re: [PATCH] lib/crypto: arm/curve25519: Disable on CPU_BIG_ENDIAN Message-ID: <20251104173749.GA1780@sol> References: <20251104054906.716914-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251104054906.716914-1-ebiggers@kernel.org> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Nov 03, 2025 at 09:49:06PM -0800, Eric Biggers wrote: > On big endian arm kernels, the arm optimized Curve25519 code produces > incorrect outputs and fails the Curve25519 test. This has been true > ever since this code was added. > > It seems that hardly anyone (or even no one?) actually uses big endian > arm kernels. But as long as they're ostensibly supported, we should > disable this code on them so that it's not accidentally used. > > Note: for future-proofing, use !CPU_BIG_ENDIAN instead of > CPU_LITTLE_ENDIAN. Both of these are arch-specific options that could > get removed in the future if big endian support gets dropped. > > Fixes: d8f1308a025f ("crypto: arm/curve25519 - wire up NEON implementation") > Cc: stable@vger.kernel.org > Signed-off-by: Eric Biggers > --- > > This patch is targeting libcrypto-fixes > > lib/crypto/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig > index 8886055e938f..16859c6226dd 100644 > --- a/lib/crypto/Kconfig > +++ b/lib/crypto/Kconfig > @@ -62,11 +62,11 @@ config CRYPTO_LIB_CURVE25519 > of the functions from . > > config CRYPTO_LIB_CURVE25519_ARCH > bool > depends on CRYPTO_LIB_CURVE25519 && !UML && !KMSAN > - default y if ARM && KERNEL_MODE_NEON > + default y if ARM && KERNEL_MODE_NEON && !CPU_BIG_ENDIAN > default y if PPC64 && CPU_LITTLE_ENDIAN > default y if X86_64 > > config CRYPTO_LIB_CURVE25519_GENERIC > bool > > base-commit: 1af424b15401d2be789c4dc2279889514e7c5c94 > -- > 2.51.2 > Applied to https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux.git/log/?h=libcrypto-fixes - Eric