From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8195A3161BB for ; Wed, 7 Jan 2026 14:54:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767797668; cv=none; b=TlaEf+KxouDED18juDbQYevESG9qcKZHZ8v/rsFbc/Q3Kl57qsNKzcDlSzSCSwq75xRYK0r7dfNoejQoR8TZbpR21/rmtbFZ7Q0vEEgPSacfuWsPgjPeNCya2dl6WNp08hpPezy3K5Ay75r1NF8DHoO6oIzj8t5EuI0PxQ8TtJ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767797668; c=relaxed/simple; bh=6wyb8ZxQTIgf1YIncqjJTeEg2p0X5JV9XaAhpNnwme4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=M80PVewe14xjDvvBA6y2GEsv+RdY2CwQRCOSCRCvVN89d489nLzWaxoyotvaVwo3d7W/zPxEJ0i9ibgmcAe4ciV6SyDa/27+PJBLgzYQt2Do3n87vH0RuwdXvc2zqqKzzJ4T7nSAnvPjK/ZVnhduwxAjjlQiePIHLsYHPVHkQn4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=E3Cp8yTp; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="E3Cp8yTp" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1767797665; 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=6wyb8ZxQTIgf1YIncqjJTeEg2p0X5JV9XaAhpNnwme4=; b=E3Cp8yTpYc6bN2kjg7a0b4Os59eQoCbnjOlVbsrLe3ZYu1oUV6gyyoElVOpYhu4yZ1xX2S G9BJ49apoNpKWNvIrhocZRdjxHWeZ1YOxtmblYQbFfKSjYXqMMkDCzD8aTf5ZFjz8FLSid 3wfr75dfWiotV9ikNZgd2KnFjzCUhLs= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-650-8K8Pi8sMPeixCglUgUHioA-1; Wed, 07 Jan 2026 09:54:20 -0500 X-MC-Unique: 8K8Pi8sMPeixCglUgUHioA-1 X-Mimecast-MFC-AGG-ID: 8K8Pi8sMPeixCglUgUHioA_1767797658 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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 mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 67EBD1800371; Wed, 7 Jan 2026 14:54:17 +0000 (UTC) Received: from fedora (unknown [10.45.226.75]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id B768030002D2; Wed, 7 Jan 2026 14:54:11 +0000 (UTC) Received: by fedora (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 7 Jan 2026 15:54:17 +0100 (CET) Date: Wed, 7 Jan 2026 15:54:10 +0100 From: Oleg Nesterov To: Qing Wang Cc: thaumy.love@gmail.com, Liam.Howlett@oracle.com, akpm@linux-foundation.org, brauner@kernel.org, bsegall@google.com, jack@suse.cz, joel.granados@kernel.org, juri.lelli@redhat.com, linux-kernel@vger.kernel.org, lorenzo.stoakes@oracle.com, mingo@redhat.com, mjguzik@gmail.com, peterz@infradead.org, rostedt@goodmis.org, rppt@kernel.org, syzbot+e0378d4f4fe57aa2bdd0@syzkaller.appspotmail.com Subject: Re: [PATCH] fork/pid: Fix use-after-free in __task_pid_nr_ns Message-ID: References: <20260107094058.3753465-1-wangqing7171@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260107094058.3753465-1-wangqing7171@gmail.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 On 01/07, Qing Wang wrote: > > I agree with your idea. But we don't need to fix this issue anymore, > because after reviewing the current mainline code, I found that it has > already been resolved(c418d8b4d7a4 "perf/core: Fix missing read event > generation on task exit") by moving sync_child_event() from > perf_child_detach() into perf_event_exit_event(). > > Here https://patch.msgid.link/20251209041600.963586-1-thaumy.love@gmail.com > > As a result, perf_event_read_event() no longer occurs on the problematic > path reported (i.e., the close()->perf_release() path). Great, thanks. So we can forget this problem ;) Oleg.