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 E81D23B8409; Tue, 23 Jun 2026 09:00:02 +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=1782205203; cv=none; b=uHejzZObNXBoleBpOSi3PSnXH2wvkr1VP7TVECeoBNklmEwdmfje1GsAZDFX2pu8wR8m5mIliuearrnj+9CK5L9ibM7cb8dAFukpL/t1m+8URae9QET3HGJCXicu2+7rD0Q5PFMc1Aw84XwsGiaD88l9DKZFC6iP6qqmhM8kFlg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782205203; c=relaxed/simple; bh=KXCWevaiHNf2bqeT/TW3o/o4kdJsGqvIhId7jpYROMQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=J0cjovgns3J95NZJn+LrDqbE6tyBat5+APmbqxuKnirVZBbLKelV24yDZDOjau4C81gQefTiWNRAHjGO7fi/nDCOvWnvcPdoEC009dCZ/Ck1poIy3Pu4g3KP9RTeVEe4u+spKLUl1sPDqI4Sgx6JsX4es3BHb6PseY3Bm5NglN4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZM++u5wL; 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="ZM++u5wL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE9401F00A3D; Tue, 23 Jun 2026 09:00:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782205202; bh=SCC+wdNVnXZNNrHkcj5DB7AYfXe6MM5pzfdxCLChsM0=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=ZM++u5wL+YKtpmuFpGRpVwJwVgtb/L8w4mFRPTSoGDLRLuogyF9bANy8KFhZENotE ZAHcd4yF0vufCcETS9L1qDYFPaPFNkJ4/bjnkRiIH1+0sATzNkmicMeDKi8leZkzIu P3NoDcIZUa7Osq0/YfOkp7zWxcuqw2rXSEuOKKvYyiiOyqkwzYuPb1et7N1fU2W2G5 s0SWd6LDejaUj6cHQF4nx0DyGO4l26f6ymvl9WuagqXkzYqD7S0Bh3B32z6wSQpT3m x3IQvgOoVvw5a9qaisB4hW1nTvSqF7hEejJnmtgIGR3uCADgpchR3BuHvCS7+Dr3dS m1rmjyz7P5yXg== Message-ID: <3377aaa2-2f9e-4e01-9f2d-a39cee71a465@kernel.org> Date: Tue, 23 Jun 2026 09:59:49 +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 v3] 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 09:56, 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> > --- > Changes in v3: > - Collapse the error labels so failed_stream falls through to the common > kref_put() return path, as suggested by Bryan O'Donoghue. > > Changes in v2: > - Add Fixes and Cc stable tags. > - Clarify why the probe failure path must drop the initial kref rather > than free as102_dev directly. > > drivers/media/usb/as102/as102_usb_drv.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/media/usb/as102/as102_usb_drv.c b/drivers/media/usb/as102/as102_usb_drv.c > index a11024451ceb..2e6c9b50ee5f 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; > } > > > base-commit: 9e7e6633458362db72427b48effad8d759131c35 > -- > 2.34.1 > Reviewed-by: Bryan O'Donoghue --- bod