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 X-Spam-Level: X-Spam-Status: No, score=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD436C433DB for ; Mon, 15 Mar 2021 14:18:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9319464FE1 for ; Mon, 15 Mar 2021 14:18:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237486AbhCOOR4 (ORCPT ); Mon, 15 Mar 2021 10:17:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:37670 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229862AbhCON7h (ORCPT ); Mon, 15 Mar 2021 09:59:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id ACCDD64FA5; Mon, 15 Mar 2021 13:59:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615816760; bh=kqGk0XuYjjRsOWNK4lG836j9SdgxgTuwrNWE5f5K6Ik=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bG/JT3TG3BNLKgPQlB/q7ghTt0ZCqSgjgC4AgtTFwefZxSzeoHUMiQ6bP6PSN9oBh Bab2ufUSDY9MV0ji28YUAcQGi/ZujdKDw9eEaFGp73rudNP51SFuKbmSJdOeg4cLeu epHwB7chrOYR1dl9bBYtErpfIrXXTG4yEUhCm0xk= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jann Horn , Christoph Hellwig , Catalin Marinas , Khalid Aziz , "David S. Miller" , Sasha Levin Subject: [PATCH 4.19 050/120] sparc64: Use arch_validate_flags() to validate ADI flag Date: Mon, 15 Mar 2021 14:56:41 +0100 Message-Id: <20210315135721.627067532@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135720.002213995@linuxfoundation.org> References: <20210315135720.002213995@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg Kroah-Hartman From: Khalid Aziz [ Upstream commit 147d8622f2a26ef34beacc60e1ed8b66c2fa457f ] When userspace calls mprotect() to enable ADI on an address range, do_mprotect_pkey() calls arch_validate_prot() to validate new protection flags. arch_validate_prot() for sparc looks at the first VMA associated with address range to verify if ADI can indeed be enabled on this address range. This has two issues - (1) Address range might cover multiple VMAs while arch_validate_prot() looks at only the first VMA, (2) arch_validate_prot() peeks at VMA without holding mmap lock which can result in race condition. arch_validate_flags() from commit c462ac288f2c ("mm: Introduce arch_validate_flags()") allows for VMA flags to be validated for all VMAs that cover the address range given by user while holding mmap lock. This patch updates sparc code to move the VMA check from arch_validate_prot() to arch_validate_flags() to fix above two issues. Suggested-by: Jann Horn Suggested-by: Christoph Hellwig Suggested-by: Catalin Marinas Signed-off-by: Khalid Aziz Reviewed-by: Catalin Marinas Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- arch/sparc/include/asm/mman.h | 54 +++++++++++++++++++---------------- 1 file changed, 29 insertions(+), 25 deletions(-) diff --git a/arch/sparc/include/asm/mman.h b/arch/sparc/include/asm/mman.h index f94532f25db1..274217e7ed70 100644 --- a/arch/sparc/include/asm/mman.h +++ b/arch/sparc/include/asm/mman.h @@ -57,35 +57,39 @@ static inline int sparc_validate_prot(unsigned long prot, unsigned long addr) { if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_ADI)) return 0; - if (prot & PROT_ADI) { - if (!adi_capable()) - return 0; + return 1; +} - if (addr) { - struct vm_area_struct *vma; +#define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags) +/* arch_validate_flags() - Ensure combination of flags is valid for a + * VMA. + */ +static inline bool arch_validate_flags(unsigned long vm_flags) +{ + /* If ADI is being enabled on this VMA, check for ADI + * capability on the platform and ensure VMA is suitable + * for ADI + */ + if (vm_flags & VM_SPARC_ADI) { + if (!adi_capable()) + return false; - vma = find_vma(current->mm, addr); - if (vma) { - /* ADI can not be enabled on PFN - * mapped pages - */ - if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP)) - return 0; + /* ADI can not be enabled on PFN mapped pages */ + if (vm_flags & (VM_PFNMAP | VM_MIXEDMAP)) + return false; - /* Mergeable pages can become unmergeable - * if ADI is enabled on them even if they - * have identical data on them. This can be - * because ADI enabled pages with identical - * data may still not have identical ADI - * tags on them. Disallow ADI on mergeable - * pages. - */ - if (vma->vm_flags & VM_MERGEABLE) - return 0; - } - } + /* Mergeable pages can become unmergeable + * if ADI is enabled on them even if they + * have identical data on them. This can be + * because ADI enabled pages with identical + * data may still not have identical ADI + * tags on them. Disallow ADI on mergeable + * pages. + */ + if (vm_flags & VM_MERGEABLE) + return false; } - return 1; + return true; } #endif /* CONFIG_SPARC64 */ -- 2.30.1