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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A71A9C5CFDB for ; Thu, 13 Aug 2026 09:02:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7254B6B024D; Thu, 13 Aug 2026 05:02:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6FC806B0431; Thu, 13 Aug 2026 05:02:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5ECA96B0432; Thu, 13 Aug 2026 05:02:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 2DC196B024D for ; Thu, 13 Aug 2026 05:02:24 -0400 (EDT) Received: from smtpin11.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 88FF1140561 for ; Thu, 13 Aug 2026 09:02:23 +0000 (UTC) X-FDA: 85095654966.11.29A5550 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf22.hostedemail.com (Postfix) with ESMTP id 983CFC0002 for ; Thu, 13 Aug 2026 09:02:21 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b="Cq9h/biY"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf22.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1786611741; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=itFc+ei9wQ2AisPFkcdPDGQXQgvzV1zw/qg30HEZpkg=; b=lB3bpNVaP4gEjk39uGCsQsr4tzZb5UnVd45VVOyi9AJmAYpfIllKI+IpfYFzzK0an5wTnH VhEj3lSAadmq9prowQZAlBWDwDADFuMpgEsA+bL4oozuxYS3aa4DHEcbJDKTKcpKd1rqIT WwkWgrIMxgFC4YsPbl9Qrile6tBOEf0= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b="Cq9h/biY"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf22.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1786611741; b=PgMQr25ABC9ZLbQXDgRwP9BYY/38HCISz4rTjBaXp6HhFMUp+DvLH5An1qDS0m8wYYnZsZ xbELW4ipVSRxBh9zyTIIDDHTbwywYRcC6f7e+nbH1FZDhOeHPZdF+IHujjBRuWjPSVzGUh NvIYHgqk9MS75L2UeBZCR5UwIYZl6ZU= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id E25B443BA9; Thu, 13 Aug 2026 09:02:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B3E31F00A3A; Thu, 13 Aug 2026 09:02:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786611740; bh=itFc+ei9wQ2AisPFkcdPDGQXQgvzV1zw/qg30HEZpkg=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=Cq9h/biYez7ZDggx1XDAyzOQtOqE3YYHzs46iGAd2rMJH+kJ6f4CsQzyDIQEKlHLL qqxDLE7ZdCbpGYdokBQR6rehGnNDLU/HD1bmmhBJ17QiPWej9urwhBlftexAsFFhNP PxXyIg49vQ57AlcYJtxGOs8kCJt53ADPmY/AJJpdxs3R2tElKhI2feDZARQdhtIplK AYOxBo7dxrdwdhdm8Ro90htp3Ie1zkYOjil7DSKlZ4RVfOKZOPNFIQPSft63kM5oMz 7kpA6swRbGH4Z7d8HV8uBp67PYWfhkhbp5LPncNJO09xCKi6mIJNbMm6VDrVcuHja6 QWXfeu4J7BtBg== From: "Mike Rapoport (Microsoft)" Date: Thu, 13 Aug 2026 12:01:28 +0300 Subject: [PATCH v2 5/5] x86/mm/pat: fix effective RW computation in lookup_address_in_pgd_attr() MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260813-cpa-fixes-v2-5-39b4ff90f91d@kernel.org> References: <20260813-cpa-fixes-v2-0-39b4ff90f91d@kernel.org> In-Reply-To: <20260813-cpa-fixes-v2-0-39b4ff90f91d@kernel.org> To: Dave Hansen Cc: Andrew Morton , Andy Lutomirski , Borislav Petkov , David CARLIER , David Hildenbrand , Ingo Molnar , Jason Gunthorpe , Jiri Slaby , Juergen Gross , Kevin Tian , Kiryl Shutsemau , "Liam R. Howlett" , Lorenzo Stoakes , Lu Baolu , Mike Rapoport , Nikunj A Dadhania , Pedro Falcato , "H. Peter Anvin" , Peter Zijlstra , Shakeel Butt , Steffen Dirkwinkel , Suren Baghdasaryan , Thomas Gleixner , Toshi Kani , Vishal Moola , Vlastimil Babka , Will Deacon , iommu@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, syzbot@syzkaller.appspotmail.com, x86@kernel.org X-Mailer: b4 0.17-dev X-Rspam-User: X-Stat-Signature: kp7fsehmynb6e397spjsmrnpw7c59s88 X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 983CFC0002 X-HE-Tag: 1786611741-42687 X-HE-Meta: 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 pRp+q9wt 2+K7AkgXqdfLKW1xfjlo4TMIA7ytfCDW9icmyGPQnu6kjNOI68l46eUELZPzVYK1D7OtOe/IW2bFn2qk7+VRE4LU9qiZOZwQhJYNc+7NXbgGfUlB9W+JqkYz05tm1F+Je5qtcUb+FE7C6tvAf4UTyrWUNyiw6Y9Y7NVOvJbRSgGgI4yxL4QApsV1nM1KUd3nKc5M3XBKw745VmIwScPd7vZdtzlVZ38iMLTRLlLBmWyykZfFMoMMnOLT5NFop6ZFgPkfgFRJTrnCqBmmWdzp70WJlmJGl10bY0EGOHfaqucyGCD1F3KQr8fIKgd7OG9h6qPo5umcLfDCx1nOeGhiVRlyzK+oPTcHuK7glThko96zmLvs1ALvktOjCF4B1bxL+TjNM/zsWN3RyRrsMkYoVYDLPoGVlML7+2Gk8Xmy9ysl+fFjhh+WaFzwDYZHxleArhcm4rZXQ9+mmvz0UfbFpYX7YoqiHGgfVSAMA8PcafjWaTuY= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: lookup_address_in_pgd_attr() accumulates the effective NX and RW bits of the walked page table levels so that verify_rwx() can detect mappings that are both writable and executable. The RW bits are folded into a bool with rw &= pXd_flags(*pXd) & _PAGE_RW; but _PAGE_RW is 0x2. So consider the accumulation line: rw &= pXd_flags(*pXd) & _PAGE_RW; where rw=0x1 and the right side evaluates down to 0x2. It'll end up doing: rw = 0x1 & 0x2 and rw always ends up 0. This way rw becomes false at the first level walked, regardless of the actual permissions, and verify_rwx() treats every mapping as non-writable and never reports a W^X violation. Add double negation to the right side to normalize the _PAGE_RW flag to 0 or 1. Fixes: ceb647b4b529 ("x86/pat: Introduce lookup_address_in_pgd_attr()") Cc: stable@vger.kernel.org Assisted-by: Copilot:claude-opus-4.8 Reviewed-by: Juergen Gross Tested-by: syzbot@syzkaller.appspotmail.com Signed-off-by: Mike Rapoport (Microsoft) --- arch/x86/mm/pat/set_memory.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index fbc418dfc597..430d0b448371 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -754,7 +754,7 @@ pte_t *lookup_address_in_pgd_attr(pgd_t *pgd, unsigned long address, *level = PG_LEVEL_512G; *nx |= pgd_flags(*pgd) & _PAGE_NX; - *rw &= pgd_flags(*pgd) & _PAGE_RW; + *rw &= !!(pgd_flags(*pgd) & _PAGE_RW); p4d = p4d_offset(pgd, address); if (p4d_none(*p4d)) @@ -765,7 +765,7 @@ pte_t *lookup_address_in_pgd_attr(pgd_t *pgd, unsigned long address, *level = PG_LEVEL_1G; *nx |= p4d_flags(*p4d) & _PAGE_NX; - *rw &= p4d_flags(*p4d) & _PAGE_RW; + *rw &= !!(p4d_flags(*p4d) & _PAGE_RW); pud = pud_offset(p4d, address); if (pud_none(*pud)) @@ -776,7 +776,7 @@ pte_t *lookup_address_in_pgd_attr(pgd_t *pgd, unsigned long address, *level = PG_LEVEL_2M; *nx |= pud_flags(*pud) & _PAGE_NX; - *rw &= pud_flags(*pud) & _PAGE_RW; + *rw &= !!(pud_flags(*pud) & _PAGE_RW); pmd = pmd_offset(pud, address); if (pmd_none(*pmd)) @@ -787,7 +787,7 @@ pte_t *lookup_address_in_pgd_attr(pgd_t *pgd, unsigned long address, *level = PG_LEVEL_4K; *nx |= pmd_flags(*pmd) & _PAGE_NX; - *rw &= pmd_flags(*pmd) & _PAGE_RW; + *rw &= !!(pmd_flags(*pmd) & _PAGE_RW); return pte_offset_kernel(pmd, address); } -- 2.53.0