From patchwork Tue Jan 23 00:27:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 13526693 Received: from mail-pl1-f171.google.com (mail-pl1-f171.google.com [209.85.214.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0F22A5FF00 for ; Tue, 23 Jan 2024 00:36:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705970168; cv=none; b=o4JVtQ6zBMz4KTLRIAiC6NP1vkiWEwrKnEj/S7hDWHk9QTyYKQsSOfNPPj/4dKeJvmHNZoQG1BhikntlLgGJ937mWhwwdAR/6hVvj+8f1zZ3ZwHMgVttGHKeKTAZEoHLx1BCMYYGeq9/HuFLY6EM1hAs9KK0jjp7C0fvfxMdpW4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705970168; c=relaxed/simple; bh=08gzPVNqKaIThrka0PRUXmbx8gcHwrKCAMm1CuCF8P8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=p9s5P26sa9O9POCmeqBQWflJzqGM7AAQ8y8FiWOkANmCML+90dlMytDjFJsEQLvlOs4i+5Qfg2/2edySYEykVTHUk/0Wef5cMofTxY3Vbj06u7Cdv854xQpnYibvYZC0WlPgRb1abtDsU1jhNh8jXmtW9LVtuts2ndnXwGEuVWo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=fRT0qu1b; arc=none smtp.client-ip=209.85.214.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="fRT0qu1b" Received: by mail-pl1-f171.google.com with SMTP id d9443c01a7336-1d751bc0c15so13286625ad.2 for ; Mon, 22 Jan 2024 16:36:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1705970166; x=1706574966; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=C0IWBalbPa7nBe+7qRPGByHWNgNICkmEQCfSed9PR50=; b=fRT0qu1bXS9ZtGZoXpSXONIkIFh7UtLb2IsyepAXfL2Ah8wh6fmE1Rw/ORb449ACUy l+r4Qk61/jFFe+d7sn6aEOzHuwc1rlvgXkxYKqu0ue9qh1HG3yPOQbdHILED/U1EvK8a eVemySHgabNAisfyG01oG9nwc9qNLUogv+eAw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705970166; x=1706574966; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=C0IWBalbPa7nBe+7qRPGByHWNgNICkmEQCfSed9PR50=; b=XjQDa/ECXe21zXhh5VTmAU/sKG1KL8qrTtsz2B5/muiM9vfdt92uYsjVBaMO+SemM4 1RKV+mi68T4rw8AK4pq4kfuZBRbS8gODcj7XxIt9U31R6y9sSGASf0JtbE35YW9ozvcL KGfZrNpbwCfotsD7LKx+swoAS+W8ewBuzNGNttJ9d4bdwT9h3J9QL77034UnkBW7Lsgp PNNT8gGGvCxfjrBLhR+xaObDm+7ULIGB2Abd5i9laN3AnVW/9q/KQmz3OL37CKxGufyi oXV8XE5z5qkxMS55u1qJGquIEx7UeObUC3hYOdAmYqZi7uxLSWQn+e6TnPvCiya2MwhN QW/w== X-Gm-Message-State: AOJu0Yx5HJTanvjMfe6jEQ72XqM4WWPtCPm9jsS0ayolbYdVN64c2lFa Z78gtIfj35uGWUkEpnJMyOGMGDKMkraddSBzzRQajXiXuV7d7sqpvOYs3NN7wLKGugHlfXEa5Tw = X-Google-Smtp-Source: AGHT+IFAeQqI3FFXQ9+1Lb9KSwrHLPJKfBRcl5zF9RvXxq3cLLHLHaogLpM0B8iNqUxW5Y7pLSv+tw== X-Received: by 2002:a17:903:482:b0:1d4:79b6:101a with SMTP id jj2-20020a170903048200b001d479b6101amr4643124plb.41.1705970166511; Mon, 22 Jan 2024 16:36:06 -0800 (PST) Received: from www.outflux.net ([198.0.35.241]) by smtp.gmail.com with ESMTPSA id k17-20020a170902f29100b001d707a14316sm7490995plc.75.2024.01.22.16.35.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Jan 2024 16:35:59 -0800 (PST) From: Kees Cook To: linux-hardening@vger.kernel.org Cc: Kees Cook , Jesper Nilsson , Lars Persson , Herbert Xu , "David S. Miller" , linux-arm-kernel@axis.com, linux-crypto@vger.kernel.org, "Gustavo A. R. Silva" , Bill Wendling , Justin Stitt , linux-kernel@vger.kernel.org Subject: [PATCH 39/82] crypto: Refactor intentional wrap-around test Date: Mon, 22 Jan 2024 16:27:14 -0800 Message-Id: <20240123002814.1396804-39-keescook@chromium.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240122235208.work.748-kees@kernel.org> References: <20240122235208.work.748-kees@kernel.org> Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2049; i=keescook@chromium.org; h=from:subject; bh=08gzPVNqKaIThrka0PRUXmbx8gcHwrKCAMm1CuCF8P8=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBlrwgIRQrU4z+xZKgZEZXKAJfo17xdTxqMyiWe6 GGw7oiVmY2JAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCZa8ICAAKCRCJcvTf3G3A JtNlD/0d9ZXpSr+O/WY+Z8RnA0WFcmb8q8dHDR+pV9DASBchjSH3T7j/DJE7/4sN+voKM6jipuP +b4X/XvukaDPGcJID6ZCEETKBPkMpdxZthLJ9z3AD+pID8v8vvqxW+pRFzY4po/kjeOset6zPFO 7YxbAUWVwSXk7QDgV3gYX/lK9QILRqXGRAhvOcubjgDREfAc2MbuJk4ItNqk2WcMnk53cEFtYji lJKFR1cHbwVPaSk2x/UmWTY9FIg9orR7rjJtFSCaZPayWmA4lNONN5MKTyl9QbNbB6LkGju5DJM Hd0T890SCjvldjd2bfSaiG9wW3fOFHydZMzdTnzla2TMofjeNAsC6odLW9rM59EO6ovdpQJ1M0y 4TeZl+acwIvrGJuRvXNx0Nokuls+m/qhpft8nMxOcVOmd3BVu+jgvguImnYNwmX/2gdr1tHBEEq uBNgF0pN3/zlUJqLU6Jaa55akZsk3vMrVRP+A2Tr00GdajqCWKlEYuwX7N2mQ+PojwYVoKRfsnA wgQYhoKfgkZAFdaSlsNJcKY6N951w+i8ooSo5xvTH/8LATZEBNEZ30239h/apCk/ho5GUZ/fXJM RLglccDfc4V+1WVhsOdPVy53he2MDI39X+mro/t056xBMjwT3L1D9ZvHF5GnpW4GVJs19uUshk+ ZHeju5Fy9h8Zijw== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 In an effort to separate intentional arithmetic wrap-around from unexpected wrap-around, we need to refactor places that depend on this kind of math. One of the most common code patterns of this is: VAR + value < VAR Notably, this is considered "undefined behavior" for signed and pointer types, which the kernel works around by using the -fno-strict-overflow option in the build[1] (which used to just be -fwrapv). Regardless, we want to get the kernel source to the position where we can meaningfully instrument arithmetic wrap-around conditions and catch them when they are unexpected, regardless of whether they are signed[2], unsigned[3], or pointer[4] types. Refactor open-coded wrap-around addition test to use add_would_overflow(). This paves the way to enabling the wrap-around sanitizers in the future. Link: https://git.kernel.org/linus/68df3755e383e6fecf2354a67b08f92f18536594 [1] Link: https://github.com/KSPP/linux/issues/26 [2] Link: https://github.com/KSPP/linux/issues/27 [3] Link: https://github.com/KSPP/linux/issues/344 [4] Cc: Jesper Nilsson Cc: Lars Persson Cc: Herbert Xu Cc: "David S. Miller" Cc: linux-arm-kernel@axis.com Cc: linux-crypto@vger.kernel.org Signed-off-by: Kees Cook --- drivers/crypto/axis/artpec6_crypto.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/crypto/axis/artpec6_crypto.c b/drivers/crypto/axis/artpec6_crypto.c index dbc1d483f2af..cbec539f0e20 100644 --- a/drivers/crypto/axis/artpec6_crypto.c +++ b/drivers/crypto/axis/artpec6_crypto.c @@ -1190,7 +1190,7 @@ artpec6_crypto_ctr_crypt(struct skcipher_request *req, bool encrypt) * the whole IV is a counter. So fallback if the counter is going to * overlow. */ - if (counter + nblks < counter) { + if (add_would_overflow(counter, nblks)) { int ret; pr_debug("counter %x will overflow (nblks %u), falling back\n",