From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794061804; b=QufF8WuEDbP7arWXCWTXb10Zc/I8rz8vG2JmG71swxuMP4BChIL1h4A/kgvdfWg3Cqyx +k8hCF1rbVEA+xTE77BgFB51eXyfL4hmf3MRUFqgJtNcEYeK99yxaxJ5tGIHVvwTkDkbA W212d6BlfBZSGeqjX01GkR/It02CpC8vyM3gaFfkyrw+6Et2C/eVnn24i4TJO/Xh50Ixo Q70twD8pyWBz2qnml64TbPtJ8o8n1W+YSLAGFvEW/zyPyBwN/XSJRfB8N/j+vlN58xEHF PScmGE/xS4BbtRLmw67ehf11Q5vNtIYNFU9or/9BVvvO72PDokJusjf8MaHrCiZZyiw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794061804; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=vk9TipY78VzBICyWEBPNnhuznFFrXdnYwXD65cNCwUw=; b=hopCGyG/7UHOSzPcDfzVCSWRyTSh3u1iMy6YW+an84lHKdXVXtylVW3umq9FilIwyyTy +D5CAIbmzwaLjwnQxvhOlBOLN5MjVlKCssOXE2zaE+cGmjvp8kc09NbQ7xphRdD05TH8s E9OFRS5AZnhb4CiPomXPRUYSLClBAVOp3hxS5p6CoiR+hQaFkwauu1uB+2iOwo0ZF0Ho9 ghzak0fKKi/Mu+WQnRkTuVS/bMIDBoldubExsY8PxRBNlzZkRR85hBfv9+4z/qu/9sMOU mYdfcc2p4Buft7Vs3tlRt8mSId2z+mplbE6IltOoEOwJUhiPpRnNi4X9Esx7sKn0kpQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=VBxdW+F2; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1B694606A326; Sat, 7 Nov 2026 14:30:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=VBxdW+F2 Received: by smtp.kernel.org (Postfix) with ESMTPSA id B36AE1F008A4; Sat, 7 Nov 2026 14:30:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794061803; bh=vk9TipY78VzBICyWEBPNnhuznFFrXdnYwXD65cNCwUw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=VBxdW+F29FD+Suie3KbwBjXJeXeEdaba0QcX4tGlhrATEKv1X6pkdgplxKyZdLlBn JTJg6OfuWd/t+iuge1zE7ylIE8/xtmIuhWQpwEqVMwUm3ZsZsIaBqI2oMMz6h6RqBL 1XZVFMOazZnQ/VdxMXnSRxiFHPn9xFHPsReU0xZM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Mike Rapoport (Microsoft)" , Dave Hansen , Juergen Gross , "Lorenzo Stoakes (ARM)" , syzbot@syzkaller.appspotmail.com, Atish Patra , Nikunj A Dadhania Subject: [PATCH 6.12 0792/1536] x86/mm/pat: Fix effective RW computation in lookup_address_in_pgd_attr() Date: Sat, 7 Nov 2026 08:46:48 -0500 Message-ID: <20261107135019.786696968@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mike Rapoport (Microsoft) commit ebaf7c9bbb1e16523d7036e7e1225ad2dfcc6482 upstream. 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. Assisted-by: Copilot:claude-opus-4.8 Fixes: ceb647b4b529 ("x86/pat: Introduce lookup_address_in_pgd_attr()") Signed-off-by: Mike Rapoport (Microsoft) Signed-off-by: Dave Hansen Reviewed-by: Juergen Gross Reviewed-by: Lorenzo Stoakes (ARM) Tested-by: syzbot@syzkaller.appspotmail.com Tested-by: Atish Patra Tested-by: Nikunj A Dadhania Cc:stable@vger.kernel.org Link: https://patch.msgid.link/20260813-cpa-fixes-v2-5-39b4ff90f91d@kernel.org Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/pat/set_memory.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -682,7 +682,7 @@ pte_t *lookup_address_in_pgd_attr(pgd_t *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)) @@ -693,7 +693,7 @@ pte_t *lookup_address_in_pgd_attr(pgd_t *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)) @@ -704,7 +704,7 @@ pte_t *lookup_address_in_pgd_attr(pgd_t *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)) @@ -715,7 +715,7 @@ pte_t *lookup_address_in_pgd_attr(pgd_t *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); }