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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 24EAAC0650F for ; Mon, 5 Aug 2019 13:22:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F02092075B for ; Mon, 5 Aug 2019 13:22:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565011367; bh=iqHwHrhpIETGLfGzdmgKsSWSRbnrsCeUGwFDY/Lb73g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JCaeGZyOzgefHiZxjg0wytlx3vXe+c7QMNu94G62HJUeLuCk03s0tAoqCt0UWIZNb 1gCqes/FgqrbrkDS3jN/wvXf1OQvZ8PbDz6N55tVsgoeO+t6/3JEndxsTkOzPYGyf4 TRGC65WI00Ejfhp45NcrbS8ut/Ri2RvoMsUwFn3c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729989AbfHENWq (ORCPT ); Mon, 5 Aug 2019 09:22:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:59364 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730748AbfHENWp (ORCPT ); Mon, 5 Aug 2019 09:22:45 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 33B2B20657; Mon, 5 Aug 2019 13:22:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565011364; bh=iqHwHrhpIETGLfGzdmgKsSWSRbnrsCeUGwFDY/Lb73g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ra3jWoW9Y1D/CK4YrpLujSsCpkwbblYd2n3zPjZeAjdb4wJ6AZ9Sy3FQ6YVsj+pRw xNH45rmOY5Ibtek6xhfrioIL0ypHmY0fu2JF1yNMlI0fLcmGgC3FJvUD7oAobt8dOv 1H65qRo0bmadIuwJEdFo2grjG3DK/yiLdvwTtUn4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vegard Nossum , Eiichi Tsukata , "Peter Zijlstra (Intel)" , Thomas Gleixner , "Joel Fernandes (Google)" , Sasha Levin Subject: [PATCH 5.2 065/131] stacktrace: Force USER_DS for stack_trace_save_user() Date: Mon, 5 Aug 2019 15:02:32 +0200 Message-Id: <20190805124955.820469238@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190805124951.453337465@linuxfoundation.org> References: <20190805124951.453337465@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit cac9b9a4b08304f11daace03b8b48659355e44c1 ] When walking userspace stacks, USER_DS needs to be set, otherwise access_ok() will not function as expected. Reported-by: Vegard Nossum Reported-by: Eiichi Tsukata Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Tested-by: Vegard Nossum Reviewed-by: Joel Fernandes (Google) Link: https://lkml.kernel.org/r/20190718085754.GM3402@hirez.programming.kicks-ass.net Signed-off-by: Sasha Levin --- kernel/stacktrace.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c index 36139de0a3c4b..899b726c9e98f 100644 --- a/kernel/stacktrace.c +++ b/kernel/stacktrace.c @@ -226,12 +226,17 @@ unsigned int stack_trace_save_user(unsigned long *store, unsigned int size) .store = store, .size = size, }; + mm_segment_t fs; /* Trace user stack if not a kernel thread */ if (!current->mm) return 0; + fs = get_fs(); + set_fs(USER_DS); arch_stack_walk_user(consume_entry, &c, task_pt_regs(current)); + set_fs(fs); + return c.len; } #endif -- 2.20.1