From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 C50BB3839BD; Thu, 6 Aug 2026 15:29:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786030183; cv=none; b=m8hwp2SjmMN2iW79DrFcoumbseFx0rviUJ+N2r1gMSdqV3Bl2U+wUNT1sesZvkWas6JHEuInBgg4mpT7ef9sBYOhUx+NzV0EiFZmC9XxsfpRvgBUXTWw01kAUa3eD+r1yOtC/lRBK34c0XYw3rvcPzNHelOzmKBCx53pZX/GLKI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786030183; c=relaxed/simple; bh=kqrTdqTxsSFEwpyxOMxu0i2WeLbZuurMpbJw2mE/1VI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=oo73wOcVr1PZn2ERo+2+WpsNlIJbnZu517GB7gfPx2U9Fo915RZe3rT4fglzQeRHB6HRrRzzdmGkon2r+7WHS+ltsNw2n8x2/Qrj1cLIL2QnGn+gTrE9lEdWlt3XfSaS6D6YJ4sQ0dKP/zkAxZhhAfRAb1BIQYyobV3iF1XNrzI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HX5OBluE; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="HX5OBluE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3E711F000E9; Thu, 6 Aug 2026 15:29:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786030182; bh=1xeD69Ldhyg8SF15ND4Gphd2g+OF9/6lMyGYU7KCDWc=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=HX5OBluEaWkJ1hu+TlG/xqt6fb6mWLDWakkoRaYVnqEbPf/J8cGl3tAnhLUoNOhxN eLUYaNnh9iyNjcm+DyWumHt25eCbmvQk8KIYVr37B+LZJkn9RquzvhAeHP1V75xDpV t7y7IT8Lle+KfPang7lrvgakqj4T8DxNIj4IU0jo= Date: Thu, 6 Aug 2026 17:29:24 +0200 From: Greg KH To: xk c Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 6.1.y] Fix memory leak in io_wq_create() on success path Message-ID: <2026080636-financial-iron-4bd9@gregkh> References: <20260806142314.557312-1-shinnkka1@gmail.com> <2026080644-suffix-earthy-2f30@gregkh> 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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Thu, Aug 06, 2026 at 10:47:02PM +0800, xk c wrote: > Greg KH 于2026年8月6日周四 22:33写道： > > > > On Thu, Aug 06, 2026 at 10:23:14PM +0800, Chen Xiaokun wrote: > > > The commit 657ca82526d0 introduced a temporary allowed_mask cpumask in > > > io_wq_create(), which was freed only on the error path. This caused a > > > memory leak of cpumask_size() bytes on every successful io_wq_create(). > > > > > > Fixes: 657ca82526d0 ("io_uring/io-wq: inherit cpuset of cgroup in io worker") > > > Signed-off-by: Chen Xiaokun > > > --- > > > io_uring/io-wq.c | 1 + > > > 1 file changed, 1 insertion(+) > > > > > > diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c > > > index 66fdd69fd6cb..34a1a9067cc2 100644 > > > --- a/io_uring/io-wq.c > > > +++ b/io_uring/io-wq.c > > > @@ -1218,6 +1218,7 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data) > > > wq->task = get_task_struct(data->task); > > > atomic_set(&wq->worker_refs, 1); > > > init_completion(&wq->worker_done); > > > + free_cpumask_var(allowed_mask); > > > return wq; > > > err: > > > io_wq_put_hash(data->hash); > > > -- > > > 2.55.0 > > > > > > > > > > Why is this a stable-only patch? Was the backport wrong? Or is this > > also in Linus's tree? > > > > Linus's tree has not this issue. You need to explain why, in great detail, Linus's tree does not have this problem in the changelog. For example, try answering the questions I asked here, that should provide you a framework for what to write. thnanks, greg k-h