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 39F482F8EB0; Sat, 12 Sep 2026 13:52:33 +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=1789221154; cv=none; b=ZyK/VnbJAjyq6JSFyFVMMTEv79NFfQGcxvZowyUlU1ZGL/zpf4k+Aum+dWq+p5q3bxzwMmEWcK3BJZ3Ma/6n/9dwcLoVxdwx2jnro9Rl4SHBj6bH3iiF1mxQopejWNMnOEBdrRJ/8YERCg/TemoszqrK3zzq6onmfLb2Wp+I688= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789221154; c=relaxed/simple; bh=aeCgUmGAi3rPYNI4N/g7Nm0/2HT9lfzhn8BoRlye+6o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Mzf9It6BHDqiJDkfAa4Yqvzl5tSuTBjN5g/dg8dV57WQtZxZCvGxBfSgMxI4acBNk0kI+Wn/f5/dx2MPJpS7XaolEmWTTIGj0jVvolQb2SVWqyxZixkQGYWEOXya9R0CQSe9Zw9r42DbchLTNIVG9o2kAfC2vepUglnvlw7L3vE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vqvX+XZT; 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="vqvX+XZT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3FBD01F000FF; Sat, 12 Sep 2026 13:52:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789221153; bh=hc/IdaWuBQJjQmdns8KQzmRNgC2J0FSP9pYelr1GvgM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=vqvX+XZThs9DA0tHyXZBHyBuRsa/TRqf7+HFIMBh8wp9qquMDwoKWVMkFygXWq0Zb 4FoHmfr85T9/a/y6OJPUjXR/x1ZyRnjZhfnyA87b+tq+brlHg2Ybq+icjrFWHaFlFv si5eftjg2F39573b8Pl3u2av5jS8yUk8bRGTXtFw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shuangpeng Bai , Hans Verkuil Subject: [PATCH 6.6 0325/1424] media: usbtv: keep device alive while ALSA card exists Date: Sat, 12 Sep 2026 08:45:57 +0200 Message-ID: <20260912065614.563416789@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.279695368@linuxfoundation.org> References: <20260912065607.279695368@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 6.6-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),