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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8393CC072A2 for ; Sun, 19 Nov 2023 15:31:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231228AbjKSPbt (ORCPT ); Sun, 19 Nov 2023 10:31:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34156 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229642AbjKSPbq (ORCPT ); Sun, 19 Nov 2023 10:31:46 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F3980C2 for ; Sun, 19 Nov 2023 07:31:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1700407902; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=VJDSDW6Pnxgedb2WwvdXdi3IPWir2LFj6HcK4uMq+TE=; b=HJ2UPx9ik7g/XWy5UxZrE1EwMopu0Wg48qHjJ+vPp2Z4k5lMYX+YAx0ZWcaY4EcPU7L1ea 2rIjfiPxhEPrqrX4CygnqgJZwzdFDtFLL4NhDChAQIpoyydMsVqblmyc0fIud//MLjouXd qPAFt66vzh8rubWoxf6r+ftD+xS5FF8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-517-aaxRoKxrNoKaooQ-KTCq4A-1; Sun, 19 Nov 2023 10:31:39 -0500 X-MC-Unique: aaxRoKxrNoKaooQ-KTCq4A-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 910D7185A782; Sun, 19 Nov 2023 15:31:38 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.31]) by smtp.corp.redhat.com (Postfix) with SMTP id 5F08D2026D4C; Sun, 19 Nov 2023 15:31:34 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Sun, 19 Nov 2023 16:30:33 +0100 (CET) Date: Sun, 19 Nov 2023 16:30:28 +0100 From: Oleg Nesterov To: Tejun Heo Cc: syzbot , boqun.feng@gmail.com, brauner@kernel.org, cgroups@vger.kernel.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, lizefan.x@bytedance.com, longman@redhat.com, michael.christie@oracle.com, mingo@redhat.com, mst@redhat.com, peterz@infradead.org, syzkaller-bugs@googlegroups.com, wander@redhat.com, will@kernel.org Subject: Re: [syzbot] [cgroups?] possible deadlock in cgroup_free Message-ID: <20231119153028.GB29401@redhat.com> References: <000000000000f5b0d0060a430995@google.com> <0000000000009642b4060a4f017f@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/19, Tejun Heo wrote: > > On Thu, Nov 16, 2023 at 05:25:05PM -0800, syzbot wrote: > > syzbot has bisected this issue to: > > > > commit 2d25a889601d2fbc87ec79b30ea315820f874b78 > > Author: Peter Zijlstra > > Date: Sun Sep 17 11:24:21 2023 +0000 > > > > ptrace: Convert ptrace_attach() to use lock guards > > Looks like the tasklist_lock conversion in ptrace_attach() forgot _irq. > Peter, Oleg? Yes, please see Re: [syzbot] [kernel?] inconsistent lock state in ptrace_attach https://lore.kernel.org/all/20231117094531.GN8262@noisy.programming.kicks-ass.net/ Oleg.