From patchwork Tue Apr 23 07:54:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Patchwork-Id: 13639548 Received: from todd.t-8ch.de (todd.t-8ch.de [159.69.126.157]) (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 E1C994F895; Tue, 23 Apr 2024 08:03:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.69.126.157 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713859392; cv=none; b=B9mJr6cIlREq52RSODeNdRyiHuXUKSbOWihnyw29zFkbaRTNroUVs7YyQGW27ZTqPqUrBroP0KyDx5jWoOwPYf/3VP/pcA0I20PTQ0Tl9w30QIpcOaVJnoi92htqWnMo5nVXOdESdanNjiuByRqFvwEU5gEF4gLUuviVIhsFqv0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713859392; c=relaxed/simple; bh=D/3OJwMoANYNDnHN43YEhKh/XOzsWgZJBxcvKVpFvHo=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Pgjt2HeOaWpCD3/KmNZSLYs+dNlSDzoHT6KAie1wwV7ioDLlDYliyTUJ8Fa5RdZOB1OZpEKLO+JJZ2KJuHALyFvtV+HkZ6sLlP4WbvMWS4OVwcudrwd6R1kks1FiHDOaCAy/nWFcDTTuWYA9r708tCXeizJkfwjfxcf31o1+vHU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=weissschuh.net; spf=pass smtp.mailfrom=weissschuh.net; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b=Z4eTOEAy; arc=none smtp.client-ip=159.69.126.157 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b="Z4eTOEAy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=weissschuh.net; s=mail; t=1713858962; bh=D/3OJwMoANYNDnHN43YEhKh/XOzsWgZJBxcvKVpFvHo=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=Z4eTOEAyeZGZRhMLErDlHrOzyIn7K/DlkM60MPZgILl0NsHakg85D489lgcJ2pyps w8ZjrPHlpbLbeknooUuGV8AX44PHoyXa1MFbZ8JyqpCmrdU3drnEDl22/6rS7GAbFk mLBVLjPqI1ce59ORnQdEOqbJ1Zk5A8F74faI2Ijw= From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= Date: Tue, 23 Apr 2024 09:54:36 +0200 Subject: [PATCH v3 01/11] stackleak: don't modify ctl_table argument Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240423-sysctl-const-handler-v3-1-e0beccb836e2@weissschuh.net> References: <20240423-sysctl-const-handler-v3-0-e0beccb836e2@weissschuh.net> In-Reply-To: <20240423-sysctl-const-handler-v3-0-e0beccb836e2@weissschuh.net> To: Luis Chamberlain , Joel Granados , Kees Cook Cc: Eric Dumazet , Dave Chinner , linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, linux-mm@kvack.org, linux-security-module@vger.kernel.org, bpf@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-xfs@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, kexec@lists.infradead.org, linux-hardening@vger.kernel.org, bridge@lists.linux.dev, lvs-devel@vger.kernel.org, linux-rdma@vger.kernel.org, rds-devel@oss.oracle.com, linux-sctp@vger.kernel.org, linux-nfs@vger.kernel.org, apparmor@lists.ubuntu.com, =?utf-8?q?Thomas_Wei?= =?utf-8?q?=C3=9Fschuh?= X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1713858961; l=1205; i=linux@weissschuh.net; s=20221212; h=from:subject:message-id; bh=D/3OJwMoANYNDnHN43YEhKh/XOzsWgZJBxcvKVpFvHo=; b=1RhNomBbqj6XFaD6ZYOxEHBLV6bfBHp2WGUjkt4XBn/Ez17CpMDHBnau1hMCabUBp0fIJIUhv lq3ewsWLz9gCbCEhY4DcLZnRRhb9Y2u6rar0aoKgOs7QrHrAJv1mc4Z X-Developer-Key: i=linux@weissschuh.net; a=ed25519; pk=KcycQgFPX2wGR5azS7RhpBqedglOZVgRPfdFSPB1LNw= In a future commit the proc_handlers will change to "const struct ctl_table". As a preparation for that adapt the logic to work with a temporary variable, similar to how it is done in other parts of the kernel. Fixes: 964c9dff0091 ("stackleak: Allow runtime disabling of kernel stack erasing") Acked-by: Kees Cook Signed-off-by: Thomas Weißschuh --- kernel/stackleak.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/stackleak.c b/kernel/stackleak.c index d099f3affcf1..558b9d6d28d3 100644 --- a/kernel/stackleak.c +++ b/kernel/stackleak.c @@ -27,10 +27,11 @@ static int stack_erasing_sysctl(struct ctl_table *table, int write, int ret = 0; int state = !static_branch_unlikely(&stack_erasing_bypass); int prev_state = state; + struct ctl_table tmp = *table; - table->data = &state; - table->maxlen = sizeof(int); - ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); + tmp.data = &state; + tmp.maxlen = sizeof(int); + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); state = !!state; if (ret || !write || state == prev_state) return ret;