From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-188.mta0.migadu.com (out-188.mta0.migadu.com [91.218.175.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8944E36A022; Thu, 11 Jun 2026 21:36:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781213801; cv=none; b=MaJtsRTeXlkdFv8RlmBxwmcelOUW9oUJKJYYGs08aeH3ts+X9jnJGMYS30OQUEYHvd+w/xamq6Z+vmrR1SPyTqSLzKotMuIN5NPtChDmVErm2eXvX0/e+niw58EArlGWCHbAr8f7dkw1kHIJqf/bQ764NElEwVncgMLtPqVjc4A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781213801; c=relaxed/simple; bh=t3+XshRL09d6biiCDeS6+8HgJOqrtebPzUOHS7SPm6k=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=WyvbtYXWfXoA2r3NX2QDsAbA3uubCBd5cnNVygA+twO0Pb6lgxVggOwO9Wy6dFQG6qSsZSVnSCGI+WyYGTsfwe1/nIYkAW57irBBPkTqBxsta3TuGX/rD8cXHcSPa9ExRaWfmZtz+6bhKbm+EScd+DEVsSeMgUWKwrk0P4KkG38= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=CnfkFdcz; arc=none smtp.client-ip=91.218.175.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="CnfkFdcz" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1781213796; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=4IEYPeJLO0t9DaZJvm8UdXCFj3OVpL5b6N7+5vqSmAM=; b=CnfkFdczXxEtBWpFsK09nkHE+qs7/SNLcVWSFr7Qyk68N+85DMXki4safyWUeTckt7e5eY QuNVPLYSv1SxSWhWRl8dpJEzWNb3yIqNL+JfN3uD1sBvVWbb2Ua7IQxsrFDA9isR0NoxIq fJ9cxPql9SHb/zQkl026p23CWsnnVBk= From: Thorsten Blum To: Thorsten Blum , Herbert Xu , "David S. Miller" , Nicolas Ferre , Alexandre Belloni , Claudiu Beznea , Tudor Ambarus Cc: linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] crypto: atmel-ecc - reject hardware ECDH without a public key Date: Thu, 11 Jun 2026 23:36:17 +0200 Message-ID: <20260611213617.463552-2-thorsten.blum@linux.dev> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1198; i=thorsten.blum@linux.dev; h=from:subject; bh=t3+XshRL09d6biiCDeS6+8HgJOqrtebPzUOHS7SPm6k=; b=owGbwMvMwCUWt7pQ4caZUj3G02pJDFnaWoFBFQuVMq/xcyz+nMKspOjcrf85xeLnmvo3/ktv8 pYs93vbUcrCIMbFICumyPJg1o8ZvqU1lZtMInbCzGFlAhnCwMUpABP5L8jwT/fdO3/5j8vut/Xa /b88/dvMVQxVZp1LH7e8UTu3JXri/qmMDL9t9Ld3C6TUrLuiJy8ttMm5cf52Bs6F2+ZvNhVZtsd cnhkA X-Developer-Key: i=thorsten.blum@linux.dev; a=openpgp; fpr=1D60735E8AEF3BE473B69D84733678FD8DFEEAD4 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT The hardware ECDH path in atmel_ecdh_compute_shared_secret() uses the private key stored in the device. However, the public key is cached only after atmel_ecdh_set_secret() successfully generated that private key for the current tfm. atmel_ecdh_generate_public_key() already rejects requests when no public key is cached. Add the same check to atmel_ecdh_compute_shared_secret() to prevent the device from using a private key that was not generated for the current tfm. Fixes: 11105693fa05 ("crypto: atmel-ecc - introduce Microchip / Atmel ECC driver") Signed-off-by: Thorsten Blum --- drivers/crypto/atmel-ecc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c index 93f219558c2f..542c8cc13a0f 100644 --- a/drivers/crypto/atmel-ecc.c +++ b/drivers/crypto/atmel-ecc.c @@ -173,6 +173,9 @@ static int atmel_ecdh_compute_shared_secret(struct kpp_request *req) return crypto_kpp_compute_shared_secret(req); } + if (!ctx->public_key) + return -EINVAL; + /* must have exactly two points to be on the curve */ if (req->src_len != ATMEL_ECC_PUBKEY_SIZE) return -EINVAL;