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 X-Spam-Level: X-Spam-Status: No, score=-14.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D2ABC433E1 for ; Fri, 12 Jun 2020 04:53:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55AA220792 for ; Fri, 12 Jun 2020 04:53:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="JcsAjc7w" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726391AbgFLExW (ORCPT ); Fri, 12 Jun 2020 00:53:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725862AbgFLExW (ORCPT ); Fri, 12 Jun 2020 00:53:22 -0400 Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 057D5C03E96F; Thu, 11 Jun 2020 21:53:22 -0700 (PDT) Received: by mail-pl1-x642.google.com with SMTP id g12so3255574pll.10; Thu, 11 Jun 2020 21:53:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=zCSuxwEDtuJ9zf1mhrD1sDdbW3HCFiaQTMtlkEwhjQg=; b=JcsAjc7wbX41+n8F9s6SlcLw2idm+q+x/n8TTJXnZimxnYNQsui0Zo6TV2pZ8jVnT7 lNNjYw1R42kj45fYrPe2M4Kh/iLbRCpdqFIqQ8wZ07GCiY4vwS/ipCyt/r1BpScjdrXS RTCeWhu9tHqjqThXOozO3KFYawMFO9KxdO/xW9Ih+DBb6O0Rast/WtgX/we5T2HDHXCt OxrLTdcLDVNl4CuYyLEhTr+vkBcy78wdvnQIKHHhIdUcRJdsIsIr+bsDFOwc3u1r2mEf +OQ5O1y+xZJNeE35BVjLnhr9ROfILM0GotEhUy5Xw9wf5dOfjKRzXiwsH7fCgf1b8AxO 2BGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=zCSuxwEDtuJ9zf1mhrD1sDdbW3HCFiaQTMtlkEwhjQg=; b=QB4Dn5DVwi7IfHYvK8ltXieVF+MMdSgGkuYZD+jVSPN+z1GaSYfC7OMrVbKykA05jK Vn3kaaXq5YqcPvRr8fAG+3z+H0mWw2md4xrk4HGOPpk3opWIiwi9INjh9pV5pMXgzQQk TPwTxjxO3GNoJ1sUipXG3YtDt9afiw89ioiso8n9gv4ucc2gkaOPn+h7JhkIaO/KB4UQ C0Qxx9UHl6QiP6rXF1knkRFue9BbWzRXvDG0QIjfkp+2CXITHjTq1PykQERthXC1TIr3 gApG6wQ/LF2Rs4ugGT+9LvZGsZD/gJn941UAQ/v/3kgzLxUpmqsLFG6GDSUbPcCxouDs 2StA== X-Gm-Message-State: AOAM531UA6fjysv988VlslnI3qfrOelhWE1/pysKifxp5o928HzAIPrE h5wb08jMWHLS+XfBH/l57H0= X-Google-Smtp-Source: ABdhPJww5vV+JroKn6WK+lcyhxjWEBwGZRdmKGmudYnyrLCVr1n8VtcddT8rciIVS+2HFoKQIb0anA== X-Received: by 2002:a17:90a:f0d4:: with SMTP id fa20mr11226260pjb.160.1591937600684; Thu, 11 Jun 2020 21:53:20 -0700 (PDT) Received: from Ryzen-9-3900X.localdomain ([89.46.114.134]) by smtp.gmail.com with ESMTPSA id w206sm4735757pfc.28.2020.06.11.21.53.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Jun 2020 21:53:20 -0700 (PDT) From: Nathan Chancellor To: "Rafael J. Wysocki" , Len Brown Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Kees Cook , Sami Tolvanen , Nathan Chancellor , yuu ichii Subject: [PATCH] ACPI: sysfs: Fix pm_profile_attr type Date: Thu, 11 Jun 2020 21:51:50 -0700 Message-Id: <20200612045149.1837-1-natechancellor@gmail.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 X-Patchwork-Bot: notify Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When running a kernel with Clang's Control Flow Integrity implemented, there is a violation that happens when accessing /sys/firmware/acpi/pm_profile: $ cat /sys/firmware/acpi/pm_profile 0 $ dmesg ... [ 17.352564] ------------[ cut here ]------------ [ 17.352568] CFI failure (target: acpi_show_profile+0x0/0x8): [ 17.352572] WARNING: CPU: 3 PID: 497 at kernel/cfi.c:29 __cfi_check_fail+0x33/0x40 [ 17.352573] Modules linked in: [ 17.352575] CPU: 3 PID: 497 Comm: cat Tainted: G W 5.7.0-microsoft-standard+ #1 [ 17.352576] RIP: 0010:__cfi_check_fail+0x33/0x40 [ 17.352577] Code: 48 c7 c7 50 b3 85 84 48 c7 c6 50 0a 4e 84 e8 a4 d8 60 00 85 c0 75 02 5b c3 48 c7 c7 dc 5e 49 84 48 89 de 31 c0 e8 7d 06 eb ff <0f> 0b 5b c3 00 00 cc cc 00 00 cc cc 00 85 f6 74 25 41 b9 ea ff ff [ 17.352577] RSP: 0018:ffffaa6dc3c53d30 EFLAGS: 00010246 [ 17.352578] RAX: 331267e0c06cee00 RBX: ffffffff83d85890 RCX: ffffffff8483a6f8 [ 17.352579] RDX: ffff9cceabbb37c0 RSI: 0000000000000082 RDI: ffffffff84bb9e1c [ 17.352579] RBP: ffffffff845b2bc8 R08: 0000000000000001 R09: ffff9cceabbba200 [ 17.352579] R10: 000000000000019d R11: 0000000000000000 R12: ffff9cc947766f00 [ 17.352580] R13: ffffffff83d6bd50 R14: ffff9ccc6fa80000 R15: ffffffff845bd328 [ 17.352582] FS: 00007fdbc8d13580(0000) GS:ffff9cce91ac0000(0000) knlGS:0000000000000000 [ 17.352582] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 17.352583] CR2: 00007fdbc858e000 CR3: 00000005174d0000 CR4: 0000000000340ea0 [ 17.352584] Call Trace: [ 17.352586] ? rev_id_show+0x8/0x8 [ 17.352587] ? __cfi_check+0x45bac/0x4b640 [ 17.352589] ? kobj_attr_show+0x73/0x80 [ 17.352590] ? sysfs_kf_seq_show+0xc1/0x140 [ 17.352592] ? ext4_seq_options_show.cfi_jt+0x8/0x8 [ 17.352593] ? seq_read+0x180/0x600 [ 17.352595] ? sysfs_create_file_ns.cfi_jt+0x10/0x10 [ 17.352596] ? tlbflush_read_file+0x8/0x8 [ 17.352597] ? __vfs_read+0x6b/0x220 [ 17.352598] ? handle_mm_fault+0xa23/0x11b0 [ 17.352599] ? vfs_read+0xa2/0x130 [ 17.352599] ? ksys_read+0x6a/0xd0 [ 17.352601] ? __do_sys_getpgrp+0x8/0x8 [ 17.352602] ? do_syscall_64+0x72/0x120 [ 17.352603] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 17.352604] ---[ end trace 7b1fa81dc897e419 ]--- When /sys/firmware/acpi/pm_profile is read, sysfs_kf_seq_show is called, which in turn calls kobj_attr_show, which gets the ->show callback member by calling container_of on attr (casting it to struct kobj_attribute) then calls it. There is a CFI violation because pm_profile_attr is of type struct device_attribute but kobj_attr_show calls ->show expecting it to be from struct kobj_attribute. CFI checking ensures that function pointer types match when doing indirect calls. Fix pm_profile_attr to be defined in terms of kobj_attribute so there is no violation or mismatch. Fixes: 362b646062b2 ("ACPI: Export FADT pm_profile integer value to userspace") Link: https://github.com/ClangBuiltLinux/linux/issues/1051 Reported-by: yuu ichii Signed-off-by: Nathan Chancellor --- drivers/acpi/sysfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c index 3a89909b50a6..76c668c05fa0 100644 --- a/drivers/acpi/sysfs.c +++ b/drivers/acpi/sysfs.c @@ -938,13 +938,13 @@ static void __exit interrupt_stats_exit(void) } static ssize_t -acpi_show_profile(struct device *dev, struct device_attribute *attr, +acpi_show_profile(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%d\n", acpi_gbl_FADT.preferred_profile); } -static const struct device_attribute pm_profile_attr = +static const struct kobj_attribute pm_profile_attr = __ATTR(pm_profile, S_IRUGO, acpi_show_profile, NULL); static ssize_t hotplug_enabled_show(struct kobject *kobj, base-commit: b791d1bdf9212d944d749a5c7ff6febdba241771 -- 2.27.0