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 7B9C038B7D2; Sat, 12 Sep 2026 11:35:40 +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=1789212941; cv=none; b=Fs3gtyrvJ1vNtMClg/BAg8eB4f2voTp1OTnKbNsKEWEtVc4OF2cpFiUdRmPxv1ax5kVOFnw54lUZ3M0cjq5c+0ygNEa2KKC4jqPIqIQP1jscYtyrjKADBJD2giBS1/Fyket/gkch/8RbnrGzap2hjbGlixtvdaF+R5ByIHnYhWA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789212941; c=relaxed/simple; bh=kIHCNYZDCnxt5ICIoe9MbCJbyzwwda7ahX91MDmm7fo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SgNMEKA/cHzbICz4J4h/KIMzrD/xENabUGsRZKuXQq+W4ttxJm0ryhQITdwgLeB7HDBei80moneA748tH25ZAzuAnjC4pgoTXK7lbjeRMwLg0dRzpLTp0z75T09DjE2tKduAVwsWtbtoHQz3/Kg+Dub2TRWPcfnGaEZvrttOF5c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VT8v6ZEp; 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="VT8v6ZEp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 806681F000FF; Sat, 12 Sep 2026 11:35:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789212940; bh=VOPnCazks1KggxNU4DvKhuQJscu+zqZoPoTpvC0aUSg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=VT8v6ZEp8rC5L+sjid0kkSr2QtYwtVbsfdwyk/66szbGM9372hhMEFvy1evAmTH65 dKwZp0r3wwSoljC/grSZHRgTfQkndRH3zGNuMEPKIAiKDsrUeC+hyZBX7RH9j67t6e knKpUWxCVrDl6zjMJP0YXvBOGFi7Gzk5XEXXgA60= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shuangpeng Bai , Hans Verkuil Subject: [PATCH 6.12 0020/1376] media: usbtv: keep device alive while ALSA card exists Date: Sat, 12 Sep 2026 08:40:46 +0200 Message-ID: <20260912065607.999108430@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.535295758@linuxfoundation.org> References: <20260912065607.535295758@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shuangpeng Bai commit fc530fe168bb2b745a93f553ad21fc25fd9cba3d upstream. The ALSA PCM callbacks store the driver state in pcm->private_data. An open PCM file can outlive USB disconnect because usbtv_audio_free() uses snd_card_free_when_closed(). The disconnect path can then drop the V4L2 device reference and free struct usbtv before ALSA releases the substream, so a later close dereferences freed memory in snd_usbtv_pcm_close(). Take a V4L2 device reference for the ALSA card and drop it from the card private_free callback. This keeps struct usbtv valid until ALSA has closed the remaining files and freed the card. Closes: https://lore.kernel.org/r/178144969601.60470.4852887710381872458@gmail.com Fixes: 63ddf68de52e ("[media] usbtv: add audio support") Cc: stable@vger.kernel.org Signed-off-by: Shuangpeng Bai Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/usbtv/usbtv-audio.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/media/usb/usbtv/usbtv-audio.c +++ b/drivers/media/usb/usbtv/usbtv-audio.c @@ -317,6 +317,13 @@ static const struct snd_pcm_ops snd_usbt .pointer = snd_usbtv_pointer, }; +static void usbtv_audio_card_free(struct snd_card *card) +{ + struct usbtv *usbtv = card->private_data; + + v4l2_device_put(&usbtv->v4l2_dev); +} + int usbtv_audio_init(struct usbtv *usbtv) { int rv; @@ -331,6 +338,10 @@ int usbtv_audio_init(struct usbtv *usbtv if (rv < 0) return rv; + v4l2_device_get(&usbtv->v4l2_dev); + card->private_data = usbtv; + card->private_free = usbtv_audio_card_free; + strscpy(card->driver, usbtv->dev->driver->name, sizeof(card->driver)); strscpy(card->shortname, "usbtv", sizeof(card->shortname)); snprintf(card->longname, sizeof(card->longname),