From patchwork Tue Jan 23 00:27:21 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 13526738 Received: from mail-oi1-f169.google.com (mail-oi1-f169.google.com [209.85.167.169]) (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 B99BA13BE8D for ; Tue, 23 Jan 2024 00:46:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.169 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705970766; cv=none; b=Ztvn57HKE+v1Qcx0APmYb+R/kicO2Urfz09MlmcaRzx5PPhT7+kZmn3xv7BhYDjcxLAsa905pC1SjJXiAhan7HDHtKEPLxxfUSWOGaVb5QV+xgygzTW7pgBVZ6HWOBXGL0FBDe7uREpqwQ0Zk6jpR7nUc+yYf3dSPcjNu69JjZg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705970766; c=relaxed/simple; bh=S3lE7Ai2Kf7cSpp8TfXi2drtS9rqiWeq8QqsQWJ+YHQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=XxJpo2skReAC73/ByslZMXI6aMBflc+NN37UdDDH0mydUjsmDUOJmddvBzHUZrYOklrwnAArDcSzDhZPLKjGDFXRaIzQ9JVAjJixattDu0mZM8anvPWqC81hSqlqy3E3Ll6YgwTgurBT7SsAwnfPWlret9xEbACV73s6ry53jl0= 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=h0bylp0f; arc=none smtp.client-ip=209.85.167.169 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="h0bylp0f" Received: by mail-oi1-f169.google.com with SMTP id 5614622812f47-3bd7c5b2439so2220907b6e.1 for ; Mon, 22 Jan 2024 16:46:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1705970764; x=1706575564; 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=MA2z3IWjgPLju653GpnPneuk8sSXMYIY7MDwgOrEeUA=; b=h0bylp0fFqwPx5/BKMBfmW9USISNvvpat7KoDOX5suv4LUlXw9P7Q3Sxv3EjiwwCTE cdMxROs0Fyiallp3UyEZVE5/2Sb+yBk2Ec64nZq1M4Cz5J/W14VmMQETuvQtAkPgxVvl F6uD1ygL6z4fkZcaIzqI//b2tj7OGwZcVOFaA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705970764; x=1706575564; 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=MA2z3IWjgPLju653GpnPneuk8sSXMYIY7MDwgOrEeUA=; b=Vyd7LMG64PN5dHtV7JIaMt3gSAG8EUIgt/dTtg8MDN+g3x+Brbe6TWrlqre0aPGDK1 0NjMXqRIft0X52sRjvcDIAcyQMbWvLQ7zgyGddBPIe7sCB6719DZ8GUUtC4PiWEAypT1 Chw1iWqPv0uELH74+YNxgHO08GVoLIVQpwog7Ps3JP6GPA7fnTIRkjM5HImgEf78Y/fZ gHFAeow8ayomcue9Ua+Y85TnQTTiPHq7tFpx5JTsGrIPau+f4acXwzAfp0HDZGltmtBl LMMT5EzD4FXYsLR+ihpdFCcIZZb7RN8kVfNVRvxZDrKOlvmYSJnSDHc/Sbz5OiwK7xYH A5Rw== X-Gm-Message-State: AOJu0YwEqhwPWtsc26IdQdc5a74JEVGGSytf1+BaVghBl4WFdkTCFm2l Sx8Jv6ja9zRfXNjt6UVUDSGAh6AEyBmu6iMZfWa1H5WXB+WmcsICFiFZOMBXvuLYluwi3BJRipw = X-Google-Smtp-Source: AGHT+IE82MRtpWX2VuxmOTfFHh+1PdFwz2wQFqX8x+zaJmrylEg5bhZ1KNGEdB6W0UvaQn+s9Twnpg== X-Received: by 2002:a05:6808:2129:b0:3bd:bc0b:c87f with SMTP id r41-20020a056808212900b003bdbc0bc87fmr1947843oiw.4.1705970763993; Mon, 22 Jan 2024 16:46:03 -0800 (PST) Received: from www.outflux.net ([198.0.35.241]) by smtp.gmail.com with ESMTPSA id fm27-20020a056a002f9b00b006d9af7f09easm10145496pfb.29.2024.01.22.16.45.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Jan 2024 16:45:57 -0800 (PST) From: Kees Cook To: linux-hardening@vger.kernel.org Cc: Kees Cook , Herbert Xu , "David S. Miller" , Aditya Srivastava , Randy Dunlap , linux-crypto@vger.kernel.org, "Gustavo A. R. Silva" , Bill Wendling , Justin Stitt , linux-kernel@vger.kernel.org Subject: [PATCH 46/82] crypto: Refactor intentional wrap-around test Date: Mon, 22 Jan 2024 16:27:21 -0800 Message-Id: <20240123002814.1396804-46-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=2489; i=keescook@chromium.org; h=from:subject; bh=S3lE7Ai2Kf7cSpp8TfXi2drtS9rqiWeq8QqsQWJ+YHQ=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBlrwgIFrBJhDm8/jRsFp5KXXGFXlyQFO17YIpWk HrPa3eVKkyJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCZa8ICAAKCRCJcvTf3G3A Jv49D/46BDju32aQxhOHgZ6jc2ZxPYAa53gwYTEJs+crMQPxDAN2g9jCf9nyc2aDOCuLyDxZWKv rBrW3Ld9k2n7w4TWBQjl2B89slARHYYcfCgy71yrkGMpZhP+AVm/9C/sLAH69LUI9ODAmK1q12F LkTNTAnPMY6dinzgDjQ+tllqpakQz2Ah6/lrR3H3r7Re7yOd3Xe48z9tLhWRDb2kjaYYw+t+yE8 SWyHOWVvBt9a8zReyFGDuTVfk7XOf95taKBrnX+O0UonyU7lyjzXWBNobIV1c66tELuOSswIo/i 1kTJjl33xCiawkV/3eVMtvKZSUrQtFkckdg97HTQGJLKfLRzsfuWCEk4D7kgZ34+moGOI552zpo JTeh90ye5RwpqdtGoFBHCcs8+SfYFKRqtWwXtfj+iT5bvKGS318taLFS8/8ewnoI6V5dfbIxPwS FKj0LY8yDtgFnuDBJc+KqgeeCLIbsUeaYVQGccyMg+wbILzGUqTSbFLhtOLuBaPRT/hAcSexQ0Y /zji0LX72YqpF4NiRVweeuBbx2CTHDIuhko3l5ci0fTQhzvn+0kcjMjikO8YqQPgE/0IfdQ4o7V KPl6sJgP/PwfUOy6JiC5Xva6wJJ7Zh3AmgEWDbmyjPyAX4iD9JbKa+gndk+Wkk1RABXlj1qz+UT 3sDol/meOz7ZHoQ== 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: Herbert Xu Cc: "David S. Miller" Cc: Aditya Srivastava Cc: Randy Dunlap Cc: linux-crypto@vger.kernel.org Signed-off-by: Kees Cook --- crypto/adiantum.c | 2 +- drivers/crypto/amcc/crypto4xx_alg.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/crypto/adiantum.c b/crypto/adiantum.c index 60f3883b736a..c2f62ca455af 100644 --- a/crypto/adiantum.c +++ b/crypto/adiantum.c @@ -190,7 +190,7 @@ static inline void le128_add(le128 *r, const le128 *v1, const le128 *v2) r->b = cpu_to_le64(x + y); r->a = cpu_to_le64(le64_to_cpu(v1->a) + le64_to_cpu(v2->a) + - (x + y < x)); + (add_would_overflow(x, y))); } /* Subtraction in Z/(2^{128}Z) */ diff --git a/drivers/crypto/amcc/crypto4xx_alg.c b/drivers/crypto/amcc/crypto4xx_alg.c index e0af611a95d8..33f73234ddd9 100644 --- a/drivers/crypto/amcc/crypto4xx_alg.c +++ b/drivers/crypto/amcc/crypto4xx_alg.c @@ -251,7 +251,7 @@ crypto4xx_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)) { SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, ctx->sw_cipher.cipher); int ret;