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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 AF75CC76188 for ; Sat, 20 Jul 2019 11:10:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7BE352084D for ; Sat, 20 Jul 2019 11:10:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="URTrCFk4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728001AbfGTLKb (ORCPT ); Sat, 20 Jul 2019 07:10:31 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:60874 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727974AbfGTLKb (ORCPT ); Sat, 20 Jul 2019 07:10:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=CSpqqObHAXL3FQ2tTs5Na9vOWdPfphA5nFF5rAves+c=; b=URTrCFk4EzVMuy5SsviQyIhiZ FihaCwluGuw0RwVRDexdapCcVI+KG+Njug+HVIrcUZ5OCnmGj5pjGBBP9wC8zHw3leY5a4neaDP1c wfiICAFvyStwamBskit2b6OqtZMhXWmRcGhH+IRpEfzkoLHkbzbmBHnopniT85knl355H+QHVpJ7O xP50SIi5BdiU8K7WfvtezZnPF2nkQ3KWC+549GtpMA1vgn/uyHvyt6WYG0KdNniWFuHYh54IVwnPC 2Xx3aXLFrV1OngTv6az97LW4LTzRje0IMM4O72j+REw5kL8NfPVY0qFUfbA3GL7NbNvbJ21oVAOAm RZhbIe9UA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1honFn-0007Jx-Ud; Sat, 20 Jul 2019 11:10:16 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 6CABF20BAF36C; Sat, 20 Jul 2019 13:10:13 +0200 (CEST) Date: Sat, 20 Jul 2019 13:10:13 +0200 From: Peter Zijlstra To: Luis Henriques Cc: Linus Torvalds , Waiman Long , Borislav Petkov , Will Deacon , huang ying , the arch/x86 maintainers , Thomas Gleixner , Tim Chen , Ingo Molnar , Davidlohr Bueso , Linux List Kernel Mailing , "H. Peter Anvin" , Jeff Layton Subject: Re: [PATCH v8 13/19] locking/rwsem: Make rwsem->owner an atomic_long_t Message-ID: <20190720111013.GQ3402@hirez.programming.kicks-ass.net> References: <20190520205918.22251-1-longman@redhat.com> <20190520205918.22251-14-longman@redhat.com> <20190719184538.GA20324@hermes.olymp> <2ed44afa-4528-a785-f188-2daf24343f97@redhat.com> <87h87hksim.fsf@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87h87hksim.fsf@suse.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jul 20, 2019 at 09:41:05AM +0100, Luis Henriques wrote: > [ 39.801179] ================================================================== > [ 39.801973] BUG: KASAN: use-after-free in rwsem_down_write_slowpath (/home/miguel/kernel/linux/kernel/locking/rwsem.c:669 /home/miguel/kernel/linux/kernel/locking/rwsem.c:1125) That's rwsem_can_spin_on_owner(), specifically line 669 seems to suggest owner_on_cpu(). So we'd somehow have a dead owner; I'm not immediately seeing how that can happen.