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=-12.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,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 62CF0C04EB8 for ; Thu, 6 Dec 2018 17:47:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 35034208E7 for ; Thu, 6 Dec 2018 17:47:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 35034208E7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726028AbeLFRrW (ORCPT ); Thu, 6 Dec 2018 12:47:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:53200 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725871AbeLFRrW (ORCPT ); Thu, 6 Dec 2018 12:47:22 -0500 Received: from vmware.local.home (unknown [208.91.3.26]) (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 2FB1920892; Thu, 6 Dec 2018 17:47:21 +0000 (UTC) Date: Thu, 6 Dec 2018 12:47:19 -0500 From: Steven Rostedt To: Linus Torvalds Cc: LKML , Ravi Bangoria , Srikar Dronamraju , Oleg Nesterov , Ingo Molnar , Andrew Morton Subject: [GIT PULL] Uprobes: Fix kernel oops with delayed_uprobe_remove() Message-ID: <20181206124719.1fa76d92@vmware.local.home> X-Mailer: Claws Mail 3.15.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus, This is a single commit that fixes a bug in uprobes SDT code due to a missing mutex protection. Please pull the latest trace-v4.20-rc5 tree, which can be found at: git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git trace-v4.20-rc5 Tag SHA1: a5405a88026387f237d97b607234db71d91c13e2 Head SHA1: 1aed58e67a6ec1e7a18bfabe8ba6ec2d27c15636 Ravi Bangoria (1): Uprobes: Fix kernel oops with delayed_uprobe_remove() ---- kernel/events/uprobes.c | 2 ++ 1 file changed, 2 insertions(+) --------------------------- commit 1aed58e67a6ec1e7a18bfabe8ba6ec2d27c15636 Author: Ravi Bangoria Date: Wed Dec 5 09:04:23 2018 +0530 Uprobes: Fix kernel oops with delayed_uprobe_remove() There could be a race between task exit and probe unregister: exit_mm() mmput() __mmput() uprobe_unregister() uprobe_clear_state() put_uprobe() delayed_uprobe_remove() delayed_uprobe_remove() put_uprobe() is calling delayed_uprobe_remove() without taking delayed_uprobe_lock and thus the race sometimes results in a kernel crash. Fix this by taking delayed_uprobe_lock before calling delayed_uprobe_remove() from put_uprobe(). Detailed crash log can be found at: Link: http://lkml.kernel.org/r/000000000000140c370577db5ece@google.com Link: http://lkml.kernel.org/r/20181205033423.26242-1-ravi.bangoria@linux.ibm.com Acked-by: Oleg Nesterov Reviewed-by: Srikar Dronamraju Reported-by: syzbot+cb1fb754b771caca0a88@syzkaller.appspotmail.com Fixes: 1cc33161a83d ("uprobes: Support SDT markers having reference count (semaphore)") Signed-off-by: Ravi Bangoria Signed-off-by: Steven Rostedt (VMware) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 96d4bee83489..98b9312ce6b2 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -572,7 +572,9 @@ static void put_uprobe(struct uprobe *uprobe) * gets called, we don't get a chance to remove uprobe from * delayed_uprobe_list from remove_breakpoint(). Do it here. */ + mutex_lock(&delayed_uprobe_lock); delayed_uprobe_remove(uprobe, NULL); + mutex_unlock(&delayed_uprobe_lock); kfree(uprobe); } }