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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 911E9C04EB8 for ; Thu, 6 Dec 2018 21:55:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 561EF2081C for ; Thu, 6 Dec 2018 21:55:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 561EF2081C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.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 S1726034AbeLFVzD (ORCPT ); Thu, 6 Dec 2018 16:55:03 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:56582 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725936AbeLFVzC (ORCPT ); Thu, 6 Dec 2018 16:55:02 -0500 Received: from localhost.localdomain (c-24-6-170-16.hsd1.ca.comcast.net [24.6.170.16]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 950F886D; Thu, 6 Dec 2018 21:55:01 +0000 (UTC) Date: Thu, 6 Dec 2018 13:54:57 -0800 From: Andrew Morton To: Steven Rostedt Cc: Linus Torvalds , LKML , Ravi Bangoria , Srikar Dronamraju , Oleg Nesterov , Ingo Molnar Subject: Re: [GIT PULL] Uprobes: Fix kernel oops with delayed_uprobe_remove() Message-Id: <20181206135457.d934354e6c1fb5ab4f5c81cc@linux-foundation.org> In-Reply-To: <20181206124719.1fa76d92@vmware.local.home> References: <20181206124719.1fa76d92@vmware.local.home> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; 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 On Thu, 6 Dec 2018 12:47:19 -0500 Steven Rostedt wrote: > > 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) > No cc:stable?