From patchwork Thu Sep 12 18:13:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Reinette Chatre X-Patchwork-Id: 828032 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.21]) (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 3128D1BF7F8; Thu, 12 Sep 2024 18:04:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.21 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726164296; cv=none; b=c5Uas364DJnM1mgX0Kq/jFyXUeLGainxvi8v8m9UFi2E/++tR7epgq1v/tWHvW62FdYZ5OCW6bFHX0tXUabeErkT2Rpl3jiyhGZ6RrymwNWqQF8RsqzVpv+mrO3Vfez6LAoovPlzc53DHCR9fqN0Gax0CANM7W4TLOk6BdEnWjU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726164296; c=relaxed/simple; bh=wPJfXOB/WVc5EYyKPe+kkP9moln0nfDFpBDGwXFRjwE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=H3iuZibApQCceMNEId2cdXcG53Ph6sLFt3U+Cnz3+1l9P4wrAx9XmmS8Ix+mFbjoUeAaQ2texdB91MM3CFNxbI/GsHEupcd6LYPkUCKVeMhcBBly8TwjRfUXsrXY7odR4WdTBU1aZjyg345gP6tHWogxoUpKLHY0zHOy4b6zXAw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=dfgeJKyP; arc=none smtp.client-ip=198.175.65.21 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="dfgeJKyP" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1726164296; x=1757700296; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=wPJfXOB/WVc5EYyKPe+kkP9moln0nfDFpBDGwXFRjwE=; b=dfgeJKyPCF1tooCUW6W0NQlb0MrjTUCmNyeIB7BR/j3exdNQkJc9JCkv NyS07LF+Bfa+H55WYWZEHkfBw9RSh0KRCrQ+mLJlguehMZEsuqjigWbKJ 01qWjnU9d97cJlzElvufvJMi345bugyFmMbJrb8y6YwsSH+QCZtoErrY6 eYLuzeb4ODpgOdqjJt0ua1YC/dh2FwVyFgbUTjWqLl3FhrL4nHl9qz8rT CpWfwg1GhB/qx12M4aqAO4A0HXvmi9A34SGJQnbiWE0oxYBLUzsuW3+NK b5RyJA1O8bcaSFBziJFQkBw2ydryYi3W3Iv7CosNdPbVZ7bbKWJeRvPnD Q==; X-CSE-ConnectionGUID: XHU55XhTSdGYTXpMulopnw== X-CSE-MsgGUID: HxL06+KwQuWHWceUm8PJ1w== X-IronPort-AV: E=McAfee;i="6700,10204,11193"; a="24976582" X-IronPort-AV: E=Sophos;i="6.10,223,1719903600"; d="scan'208";a="24976582" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by orvoesa113.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Sep 2024 11:04:52 -0700 X-CSE-ConnectionGUID: Z8Lh74GYRJ+9J7qmaMRRcg== X-CSE-MsgGUID: OD91f+VeTjaPx6Ev2nAgHQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,223,1719903600"; d="scan'208";a="67724606" Received: from b04f130c85c0.jf.intel.com (HELO rchatre-desk1.jf.intel.com) ([10.165.154.99]) by orviesa009-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Sep 2024 11:04:52 -0700 From: Reinette Chatre To: fenghua.yu@intel.com, shuah@kernel.org, tony.luck@intel.com, peternewman@google.com, babu.moger@amd.com, ilpo.jarvinen@linux.intel.com Cc: maciej.wieczor-retman@intel.com, reinette.chatre@intel.com, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH V2 03/13] selftests/resctrl: Fix memory overflow due to unhandled wraparound Date: Thu, 12 Sep 2024 11:13:52 -0700 Message-ID: X-Mailer: git-send-email 2.46.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 alloc_buffer() allocates and initializes (with random data) a buffer of requested size. The initialization starts from the beginning of the allocated buffer and incrementally assigns sizeof(uint64_t) random data to each cache line. The initialization uses the size of the buffer to control the initialization flow, decrementing the amount of buffer needing to be initialized after each iteration. The size of the buffer is stored in an unsigned (size_t) variable s64 and the test "s64 > 0" is used to decide if initialization is complete. The problem is that decrementing the buffer size may wrap around if the buffer size is not divisible by "CL_SIZE / sizeof(uint64_t)" resulting in the "s64 > 0" test being true and memory beyond the buffer "initialized". Use a signed value for the buffer size to support all buffer sizes. Fixes: a2561b12fe39 ("selftests/resctrl: Add built in benchmark") Signed-off-by: Reinette Chatre --- Changes since V1: - New patch. --- tools/testing/selftests/resctrl/fill_buf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/resctrl/fill_buf.c b/tools/testing/selftests/resctrl/fill_buf.c index ae120f1735c0..34e5df721430 100644 --- a/tools/testing/selftests/resctrl/fill_buf.c +++ b/tools/testing/selftests/resctrl/fill_buf.c @@ -127,7 +127,7 @@ unsigned char *alloc_buffer(size_t buf_size, int memflush) { void *buf = NULL; uint64_t *p64; - size_t s64; + ssize_t s64; int ret; ret = posix_memalign(&buf, PAGE_SIZE, buf_size);