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 0CDA43CE4B6; Tue, 23 Jun 2026 08:50:32 +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=1782204636; cv=none; b=lkXUcifhSIFkaTU+VasON0rAk20hzGXLRqhFIVpoyTPx1RWHnSK2Asf4BcoU9XRPai3JWiH1bdXaXwfhK9SiHejZXHLYAklrMvcINp7JmCvdpAknWZJvk62NLfBPWBurVBHJt/6s0oY1H1YnWDwW7Xgq9G/Y3+CKHj5BjdJxQAc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782204636; c=relaxed/simple; bh=SIr2vDvs0AWleStmL6oPmKjHddGSAR4/MrYLpb8EbdU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=t9e/j+8skKXFgbsxRVK4NGd5VHtZ4v5K4QpW6DHTebIyGlYNty30WoQiojGRmDQbi5jAa0S++HhAu6i+4Konx7jPIGIeLH1/Metd8d0AYe17PWcIIDFQ6517IF/jkl3rWOhQxz84pIqVzY/vP0ZnVTFxDuPKHFIEy0vRrR1HpOQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FJwUnbGs; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FJwUnbGs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 51B971F000E9; Tue, 23 Jun 2026 08:50:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782204632; bh=cby/NkFpouS46q4pLc0mukueRXBfbwYvij9ZnBXdZJk=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=FJwUnbGshGsmEZiPKt4L8heL1ZngMD58ykqyg2wIhG0ALmRms2f04kxqt1LgYGbm5 pMcNTezmDe5DrjxGHtavu8hto4nfKjhij2KJPKea0NRsvuJVz4hLhDoLLyzE/xIIlg Tc4gA/Vg/2UqmmeRmlECN38ogyXdWHgetWxCPfsivyuitYaBHAlcOD/2RMBteow12I xgeSEtOdklphyfCLW/OIVCcc53i48V/tTP6QAsu1icCsCflmaFc4iq2BY1fU5leFLk DSFYRLTr/uJ+KfEgaY8JfYpe1p5GL2jEv77uHuk8s04d/9blmUnfvW4/TIEP/fdv9P 0CU/Css1gbhHQ== Message-ID: <2d51a6ab-2d1e-4fa1-9d06-24de1ed9badf@kernel.org> Date: Tue, 23 Jun 2026 09:50:19 +0100 Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] media: as102: drop device reference on probe failure To: Jiawen Liu <1298662399@qq.com>, mchehab@kernel.org Cc: hverkuil+cisco@kernel.org, kees@kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: From: Bryan O'Donoghue Content-Language: en-US Autocrypt: addr=bod@kernel.org; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 23/06/2026 05:39, Jiawen Liu wrote: > as102_usb_probe() initializes the kref and takes a USB device reference > before registering the USB minor. > > The change named in the Fixes tag avoided freeing as102_dev directly > after usb_register_dev() succeeds, because userspace can open the minor > before a later probe failure and hold an extra kref until release. > > However, the stream-allocation and DVB-registration failure paths now > deregister the USB minor and return without dropping the probe path > initial kref. That leaves the USB device reference held by as102_dev > leaked. > > Drop the initial reference with kref_put() after usb_deregister_dev(). If > no userspace file is open, as102_usb_release() releases the USB device > and frees as102_dev immediately. If a file is open, the final free is > deferred until the last file release drops the remaining kref. > > Fixes: 8bd29dbe03fc ("media: as102: fix to not free memory after the device is registered in as102_usb_probe()") > Cc: stable@vger.kernel.org > Signed-off-by: Jiawen Liu <1298662399@qq.com> > --- > drivers/media/usb/as102/as102_usb_drv.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/media/usb/as102/as102_usb_drv.c b/drivers/media/usb/as102/as102_usb_drv.c > index a11024451ceb..ad6c5837f1d7 100644 > --- a/drivers/media/usb/as102/as102_usb_drv.c > +++ b/drivers/media/usb/as102/as102_usb_drv.c > @@ -405,6 +405,7 @@ static int as102_usb_probe(struct usb_interface *intf, > failed_stream: > usb_set_intfdata(intf, NULL); > usb_deregister_dev(intf, &as102_usb_class_driver); > + kref_put(&as102_dev->kref, as102_usb_release); > return ret; > failed: > usb_put_dev(as102_dev->bus_adap.usb_dev); > > base-commit: 9e7e6633458362db72427b48effad8d759131c35 > -- > 2.34.1 > Your kref_put() is correct but, the jump labels should be collapsed down to a single return. diff --git a/drivers/media/usb/as102/as102_usb_drv.c b/drivers/media/usb/as102/as102_usb_drv.c index a11024451cebd..2e6c9b50ee5ff 100644 --- a/drivers/media/usb/as102/as102_usb_drv.c +++ b/drivers/media/usb/as102/as102_usb_drv.c @@ -403,13 +403,10 @@ static int as102_usb_probe(struct usb_interface *intf, failed_dvb: as102_free_usb_stream_buffer(as102_dev); failed_stream: - usb_set_intfdata(intf, NULL); usb_deregister_dev(intf, &as102_usb_class_driver); - return ret; failed: - usb_put_dev(as102_dev->bus_adap.usb_dev); usb_set_intfdata(intf, NULL); - kfree(as102_dev); + kref_put(&as102_dev->kref, as102_usb_release); return ret; } --- bod