From nobody Mon Feb 9 23:15:31 2026 Received: from thorn.bewilderbeest.net (thorn.bewilderbeest.net [71.19.156.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 982781DFC9; Thu, 8 Feb 2024 01:26:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=71.19.156.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707355597; cv=none; b=td1B8pyCURM0Bs9/QwDOuvLIEmpImmlLO57zsx4T6QYfIN9psv0sdW5vVs1PjeVSpXUiEAndZir8gqgTrH2IQMYVzut1b9AMEd7bEEuYG5IdVvGPWiaDA1wbA1oI2im+ljmBVu4dI7QagZJJ+vBzQkmiGeCTUkADeuK3wyP+Tmk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707355597; c=relaxed/simple; bh=OLe7cAlE7GWmn6Aw0nOYxdFDKvQ+HmBGQMrUtAdT8nM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pbYAdsZJd353StdQ1d4jrmMrmbILiRlVyOfRBYvrgl2tk/aHp3PBMEjQnwOCvfOp2eJvzw8m0VsLtmM/Oy4IHgnTpynlq7Xc/glLkCCyM6fJOm9IUUWat9XZYqSenohIru6SY/hjUfcK7xYw7GEDEYLMPRdv1KRHZxWI4+w5eq4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=bewilderbeest.net; spf=pass smtp.mailfrom=bewilderbeest.net; dkim=pass (1024-bit key) header.d=bewilderbeest.net header.i=@bewilderbeest.net header.b=WE/8Lz4f; arc=none smtp.client-ip=71.19.156.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=bewilderbeest.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bewilderbeest.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=bewilderbeest.net header.i=@bewilderbeest.net header.b="WE/8Lz4f" Received: from hatter.bewilderbeest.net (unknown [IPv6:2602:61:712b:6300::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: zev) by thorn.bewilderbeest.net (Postfix) with ESMTPSA id 90C25DD9; Wed, 7 Feb 2024 17:26:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bewilderbeest.net; s=thorn; t=1707355589; bh=jCfZxrSPfJRHCvrnkx78xqXBFO8QXL5lwiLPbS+xTAw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WE/8Lz4fbNW5hsXgLypZFn60E7qq3727+grkoIAgUAZO+kPRV+GimPEAfRtWnfs8N BHEObsnhOydmXdgmSyMAojdnhwMYrIFvSnPrwMl8MGW8gyVf330s4rIozE0T5/dEE9 47SLwGlLubpXFlRqB6hCTSQk3VHSnmIl2CW0Z4oQ= From: Zev Weiss To: Russell King , linux-arm-kernel@lists.infradead.org Cc: Zev Weiss , openbmc@lists.ozlabs.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 2/2] ARM: prctl: Reject PR_SET_MDWE on pre-ARMv6 Date: Wed, 7 Feb 2024 17:26:20 -0800 Message-ID: <20240208012620.32604-6-zev@bewilderbeest.net> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240208012620.32604-4-zev@bewilderbeest.net> References: <20240208012620.32604-4-zev@bewilderbeest.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" On v5 and lower CPUs we can't provide MDWE protection, so ensure we fail any attempt to enable it via prctl(PR_SET_MDWE). Previously such an attempt would misleadingly succeed, leading to any subsequent mmap(PROT_READ|PROT_WRITE) or execve() failing unconditionally (the latter somewhat violently via force_fatal_sig(SIGSEGV) due to READ_IMPLIES_EXEC). Signed-off-by: Zev Weiss Cc: # v6.3+ --- arch/arm/include/asm/mman.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) create mode 100644 arch/arm/include/asm/mman.h diff --git a/arch/arm/include/asm/mman.h b/arch/arm/include/asm/mman.h new file mode 100644 index 000000000000..2189e507c8e0 --- /dev/null +++ b/arch/arm/include/asm/mman.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_MMAN_H__ +#define __ASM_MMAN_H__ + +#include +#include + +static inline bool arch_memory_deny_write_exec_supported(void) +{ + return cpu_architecture() >=3D CPU_ARCH_ARMv6; +} +#define arch_memory_deny_write_exec_supported arch_memory_deny_write_exec_= supported + +#endif /* __ASM_MMAN_H__ */ --=20 2.43.0