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=1793829110; b=GJ1wk5+va+6BqR/G65ofvTA9IgTl8TeXCyXvMWlv5eeYjb5is9KY6K3Y2+y+frULQAgj U3oAfsW18S87iDf0wKvcR1Qq5BvQG1h1FFyf8WgRS04v/NmwrSUB8Uk0dUwv/aWIncQG2 eAlPlDzjWC7akXCdNzURMK0xO4pinnBbP1nXkM/YAxiPW7AKf9hUM9zihcIgLQWQJVW9i 964IrY9KMxpIuGgOeX412u2z/7pMb95vsfaLwnetbqeQnhbiU1ctCXWCk1jJxSUTd6TrV XEZl+wAr4rzGE5OfHp//m/A8+EOWIMuU2RxFVyCt3wTUZSjZK1lmbCJuf4/9ipPKKSA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793829110; 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=19VqxPuxk7aOKyJhn8YT1Ce/Gxd7pdLsaojrsNzEMLM=; b=sTVf75KeBAkR1qMAlt7c+5G2k+yxtbpKx5Tae1AD1j+30OQvmdd99fUrx1KhNxu76rXa LmPRoojVb6uavA9TgUPKXb/lGzs8wM2VWBH8o6TlHTqitZeAVrGYqaTAv/GKLiI03h1E9 CX2OF8PA/qpyw+9X6GUpuPGEVwgIMogMJ7Her07EtRRPIg5eF3pQrLhSUIpDfWu3fH//v An1SYH6lxzhuVCJEWYtlBWbKBKYIdsleLXiPkaHKGDcs/krBYI7AFzcmi5Ma/Quzn8XK/ sbgkhyBALjYWJuB3BEfP+Pc61RP+R+o65EG2dwr6InNxWVZpNgIhB5U7O/GT48kpNJg== 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=0OzynzaI; 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 7031C6070757; Wed, 4 Nov 2026 21:51:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=0OzynzaI Received: by smtp.kernel.org (Postfix) with ESMTPSA id 165681F00919; Wed, 4 Nov 2026 21:51:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793829110; bh=19VqxPuxk7aOKyJhn8YT1Ce/Gxd7pdLsaojrsNzEMLM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=0OzynzaIUHhtgukllUChLk4EGhFapx4RJp4VMM+PnpgjZJ6sJXFBgSjxdv3/dbqHZ lqY9OdhyywCuLv94etuSP7cyH0ITyQ1byzCEiOcyyw4JNDTF39CeeY9jUCqP83p6io VNRza6QV44j0pY7Ynbael1OKTYMjfudDUalz7Tl8= 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 7.3 452/547] x86/mm/pat: Fix effective RW computation in lookup_address_in_pgd_attr() Date: Wed, 4 Nov 2026 16:10:36 -0500 Message-ID: <20261104211051.197401969@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211038.406938024@linuxfoundation.org> References: <20261104211038.406938024@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.3-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 @@ -754,7 +754,7 @@ 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)) @@ -765,7 +765,7 @@ 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)) @@ -776,7 +776,7 @@ 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)) @@ -787,7 +787,7 @@ 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); }