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 ACE8832D7F8; Sat, 12 Sep 2026 18:22:11 +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=1789237332; cv=none; b=OU7zf47cFQiniEtNguH0qd8KUICtgtysk5iLiBQslB+wociroiN4fvmucLksuSTlUclfsc449o61ey4ePqccVzRFR6WNict4ZrPNLNq4Xf1LZdHES7/VyX0uxsn4nXAJf3MEGsbK7uPmvB+rNb+M1LvOZLZaJn5yk95YklJlLMs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789237332; c=relaxed/simple; bh=z4fbBYNtzPruzVccasRe61JLTkeO8QHcBQwSmnFF+tQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=E2YNIk5Bc9492tgX4HaM+DnJSu4X4nwa4tfvQ53Axm37Ux9nmrFMlZHmVRvUJ8EeYrFG1IrO7FDiG6DklKtEi0VvaMrqxu+tUj5wWDAE9uATcnoMnsI48ZcftYPcDwV2y0w/xbbP8A5t8vVuNX2kEUXLwf8kMeZY5ObhJ7J3mvw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fuF7+b1N; 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="fuF7+b1N" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3FCD1F000FF; Sat, 12 Sep 2026 18:22:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789237331; bh=PAmZ+yRmpNBH9nSGBVdVlBv8nKdDtNP8H9DehM/ktQs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fuF7+b1NwcPTslPc21CVWJ1Zl7r7k8OFJk9K8A1BzdqQe3er2XsRrxSr+WAJ1E6PA Rvv2OmusvjUg/lc9ksgsDBNULQU1OMXDNY305ytnP+TnVFeoMsOoVl/vyX8yE/dBo7 5jD/yxx5lvvkT+tFTAi7BoyL0e7hRlCZBV72314M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shuangpeng Bai , Hans Verkuil Subject: [PATCH 5.15 237/935] media: usbtv: keep device alive while ALSA card exists Date: Sat, 12 Sep 2026 08:54:27 +0200 Message-ID: <20260912065532.263176336@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065526.833703348@linuxfoundation.org> References: <20260912065526.833703348@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 5.15-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),