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=-11.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 862D0C76188 for ; Mon, 22 Jul 2019 08:46:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5AA2F21E6B for ; Mon, 22 Jul 2019 08:46:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="rUfzbbSQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728514AbfGVIqM (ORCPT ); Mon, 22 Jul 2019 04:46:12 -0400 Received: from terminus.zytor.com ([198.137.202.136]:39529 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725989AbfGVIqL (ORCPT ); Mon, 22 Jul 2019 04:46:11 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x6M8k4xL3747427 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Mon, 22 Jul 2019 01:46:04 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 terminus.zytor.com x6M8k4xL3747427 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2019071901; t=1563785165; bh=52RxQEACFNHpKKDiBYwtFQzgC/9MJCvBPNDWb/0PFbA=; h=Date:From:Cc:Reply-To:In-Reply-To:References:To:Subject:From; b=rUfzbbSQzojaElFWJESDMaJyHPDRPPmHOgtbySaG7PUoipYSzYsHcPmx+5zDnEfbo G9c7mRfa0mf5jKO6oI1tOXKZj21aP0BLh93kkeQO7SlhA8jqQIgJyJO9qKSSSVnp3Z kGlbWWA0BTNFHcRxjmK+qqYeoO0BTc+NYGjIQVI4hyXF9KXEnI4zEwhp2lvFvQj+8u 7oDd3Hw+lJo2lQGuTLTwlyiyEqp8BM4nDQG5OHnTT8mgaMu1jDvakJPg1lg8tRkxlO P2H6KKWNXCF2ryXEQIp/Zb5QfjC20lwDenVQR6CeH+QOArDKM8f9L1FDmOmPTzsNki Iy5gt77hhwEFA== Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x6M8k4OZ3747424; Mon, 22 Jul 2019 01:46:04 -0700 Date: Mon, 22 Jul 2019 01:46:04 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Eiichi Tsukata Message-ID: Cc: hpa@zytor.com, juri.lelli@gmail.com, mingo@kernel.org, tglx@linutronix.de, devel@etsukata.com, linux-kernel@vger.kernel.org Reply-To: hpa@zytor.com, juri.lelli@gmail.com, devel@etsukata.com, tglx@linutronix.de, mingo@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20190722083216.16192-2-devel@etsukata.com> References: <20190722083216.16192-2-devel@etsukata.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/stacktrace: Prevent access_ok() warnings in arch_stack_walk_user() Git-Commit-ID: 2af7c85714d8cafadf925d55441458eae312cd6b X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 2af7c85714d8cafadf925d55441458eae312cd6b Gitweb: https://git.kernel.org/tip/2af7c85714d8cafadf925d55441458eae312cd6b Author: Eiichi Tsukata AuthorDate: Mon, 22 Jul 2019 17:32:16 +0900 Committer: Thomas Gleixner CommitDate: Mon, 22 Jul 2019 10:42:36 +0200 x86/stacktrace: Prevent access_ok() warnings in arch_stack_walk_user() When arch_stack_walk_user() is called from atomic contexts, access_ok() can trigger the following warning if compiled with CONFIG_DEBUG_ATOMIC_SLEEP=y. Reproducer: // CONFIG_DEBUG_ATOMIC_SLEEP=y # cd /sys/kernel/debug/tracing # echo 1 > options/userstacktrace # echo 1 > events/irq/irq_handler_entry/enable WARNING: CPU: 0 PID: 2649 at arch/x86/kernel/stacktrace.c:103 arch_stack_walk_user+0x6e/0xf6 CPU: 0 PID: 2649 Comm: bash Not tainted 5.3.0-rc1+ #99 RIP: 0010:arch_stack_walk_user+0x6e/0xf6 Call Trace: stack_trace_save_user+0x10a/0x16d trace_buffer_unlock_commit_regs+0x185/0x240 trace_event_buffer_commit+0xec/0x330 trace_event_raw_event_irq_handler_entry+0x159/0x1e0 __handle_irq_event_percpu+0x22d/0x440 handle_irq_event_percpu+0x70/0x100 handle_irq_event+0x5a/0x8b handle_edge_irq+0x12f/0x3f0 handle_irq+0x34/0x40 do_IRQ+0xa6/0x1f0 common_interrupt+0xf/0xf Fix it by calling __range_not_ok() directly instead of access_ok() as copy_from_user_nmi() does. This is fine here because the actual copy is inside a pagefault disabled region. Reported-by: Juri Lelli Signed-off-by: Eiichi Tsukata Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20190722083216.16192-2-devel@etsukata.com --- arch/x86/kernel/stacktrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c index 4f36d3241faf..2d6898c2cb64 100644 --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -100,7 +100,7 @@ copy_stack_frame(const void __user *fp, struct stack_frame_user *frame) { int ret; - if (!access_ok(fp, sizeof(*frame))) + if (__range_not_ok(fp, sizeof(*frame), TASK_SIZE)) return 0; ret = 1;