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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E939C4332F for ; Wed, 2 Nov 2022 02:47:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230425AbiKBCrf (ORCPT ); Tue, 1 Nov 2022 22:47:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230442AbiKBCra (ORCPT ); Tue, 1 Nov 2022 22:47:30 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAC3821822 for ; Tue, 1 Nov 2022 19:47:29 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 94993B8206C for ; Wed, 2 Nov 2022 02:47:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 71F5AC433D6; Wed, 2 Nov 2022 02:47:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1667357247; bh=tCf5rG/h/6/aUqsXCcJal3Vnhg3LW1thM2ItTkEteA4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CLC5BkokQYyuBXDjMmny05xOBs4R9djOhKbdJhmh/rBKqd2YWha4jhxW1jnb/fdzl wVdquXmRmFAoNXX7xFgED63jmwc7DWJbtW8skwcxQIoLEp6bCMadi5raWcaC+kefIS uTdnMzvzy+/ueMn1oSLvOnEThLUZlF/ZwsQKkqw8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Chang S. Bae" , Thomas Gleixner , Sasha Levin Subject: [PATCH 6.0 138/240] x86/fpu: Fix the init_fpstate size check with the actual size Date: Wed, 2 Nov 2022 03:31:53 +0100 Message-Id: <20221102022114.499640069@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221102022111.398283374@linuxfoundation.org> References: <20221102022111.398283374@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chang S. Bae [ Upstream commit d3e021adac7c51a26d9ede167c789fcc1b878467 ] The init_fpstate buffer is statically allocated. Thus, the sanity test was established to check whether the pre-allocated buffer is enough for the calculated size or not. The currently measured size is not strictly relevant. Fix to validate the calculated init_fpstate size with the pre-allocated area. Also, replace the sanity check function with open code for clarity. The abstraction itself and the function naming do not tend to represent simply what it does. Fixes: 2ae996e0c1a3 ("x86/fpu: Calculate the default sizes independently") Signed-off-by: Chang S. Bae Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20220824191223.1248-3-chang.seok.bae@intel.com Signed-off-by: Sasha Levin --- arch/x86/kernel/fpu/xstate.c | 24 ++++++------------------ 1 file changed, 6 insertions(+), 18 deletions(-) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index f0ce10620ab0..f5ef78633b4c 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -678,20 +678,6 @@ static unsigned int __init get_xsave_size_user(void) return ebx; } -/* - * Will the runtime-enumerated 'xstate_size' fit in the init - * task's statically-allocated buffer? - */ -static bool __init is_supported_xstate_size(unsigned int test_xstate_size) -{ - if (test_xstate_size <= sizeof(init_fpstate.regs)) - return true; - - pr_warn("x86/fpu: xstate buffer too small (%zu < %d), disabling xsave\n", - sizeof(init_fpstate.regs), test_xstate_size); - return false; -} - static int __init init_xstate_size(void) { /* Recompute the context size for enabled features: */ @@ -717,10 +703,6 @@ static int __init init_xstate_size(void) kernel_default_size = xstate_calculate_size(fpu_kernel_cfg.default_features, compacted); - /* Ensure we have the space to store all default enabled features. */ - if (!is_supported_xstate_size(kernel_default_size)) - return -EINVAL; - if (!paranoid_xstate_size_valid(kernel_size)) return -EINVAL; @@ -879,6 +861,12 @@ void __init fpu__init_system_xstate(unsigned int legacy_size) init_fpstate.size = fpu_kernel_cfg.max_size; init_fpstate.xfeatures = fpu_kernel_cfg.max_features; + if (init_fpstate.size > sizeof(init_fpstate.regs)) { + pr_warn("x86/fpu: init_fpstate buffer too small (%zu < %d), disabling XSAVE\n", + sizeof(init_fpstate.regs), init_fpstate.size); + goto out_disable; + } + setup_init_fpu_buf(); /* -- 2.35.1