From patchwork Fri Dec 6 10:11:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Brodsky X-Patchwork-Id: 13896862 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6361B20127D; Fri, 6 Dec 2024 10:13:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733480026; cv=none; b=MFwqt+f6voFb1J1eJbQgHKRiQ7CEYNJJLLyF5Fx12lrjvybtF5B569qgpvYR01yCXRAVFtmIbrWA59ebBNSX9nJvCgGTLNjzbMT2BWzR+WyIIgJ7OihniB+5OU4FjLMRe80b4Ie2qr5AyXiO1aHl7MxJ/ZTzqy4BPn0UUmlOMsA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733480026; c=relaxed/simple; bh=v63oPnv4YNCZSimALan027RzoLGb6aTQUE4tll0ATKE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jX2BmIFts1FL6rQKYTeB+FknHCu7eirJizmD1uFScajnufYJpyvuPp3yz/o64scihtcyeWKOWfzEsnogv65xk6PHqaVXEdVW8vhV/kP++JYF7piCTYGYTOQAuj+xRFkRRab3qRRp03Ajm0P258X7jerMIHHZWEL9Oqw7tHnq61w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DD1011691; Fri, 6 Dec 2024 02:14:12 -0800 (PST) Received: from e123572-lin.arm.com (e123572-lin.cambridge.arm.com [10.1.194.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F3AD33F71E; Fri, 6 Dec 2024 02:13:41 -0800 (PST) From: Kevin Brodsky To: linux-hardening@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Kevin Brodsky , aruna.ramakrishna@oracle.com, broonie@kernel.org, catalin.marinas@arm.com, dave.hansen@linux.intel.com, jannh@google.com, jeffxu@chromium.org, joey.gouly@arm.com, kees@kernel.org, maz@kernel.org, pierre.langlois@arm.com, qperret@google.com, ryan.roberts@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org Subject: [RFC PATCH 10/16] mm: Map page tables with privileged pkey Date: Fri, 6 Dec 2024 10:11:04 +0000 Message-ID: <20241206101110.1646108-11-kevin.brodsky@arm.com> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241206101110.1646108-1-kevin.brodsky@arm.com> References: <20241206101110.1646108-1-kevin.brodsky@arm.com> Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 If CONFIG_KPKEYS_HARDENED_PGTABLES is enabled, map allocated page table pages using a privileged pkey (KPKEYS_PKEY_PGTABLES), so that page tables can only be written under guard(kpkeys_hardened_pgtables). This patch is a no-op if CONFIG_KPKEYS_HARDENED_PGTABLES is disabled (default). Signed-off-by: Kevin Brodsky --- include/linux/mm.h | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 683e883dae77..4fb25454ba85 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -31,6 +31,7 @@ #include #include #include +#include struct mempolicy; struct anon_vma; @@ -2895,7 +2896,19 @@ static inline bool pagetable_is_reserved(struct ptdesc *pt) */ static inline struct ptdesc *pagetable_alloc_noprof(gfp_t gfp, unsigned int order) { - struct page *page = alloc_pages_noprof(gfp | __GFP_COMP, order); + struct page *page; + int ret; + + page = alloc_pages_noprof(gfp | __GFP_COMP, order); + if (!page) + return NULL; + + ret = kpkeys_protect_pgtable_memory((unsigned long)page_address(page), + 1 << order); + if (ret) { + __free_pages(page, order); + return NULL; + } return page_ptdesc(page); } @@ -2911,8 +2924,11 @@ static inline struct ptdesc *pagetable_alloc_noprof(gfp_t gfp, unsigned int orde static inline void pagetable_free(struct ptdesc *pt) { struct page *page = ptdesc_page(pt); + unsigned int order = compound_order(page); - __free_pages(page, compound_order(page)); + kpkeys_unprotect_pgtable_memory((unsigned long)page_address(page), + 1 << order); + __free_pages(page, order); } #if defined(CONFIG_SPLIT_PTE_PTLOCKS)