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 8795F42882B; Sat, 12 Sep 2026 11:48:47 +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=1789213728; cv=none; b=i3Lwd4sA81S95Z3ZcA6Ab5gRUXCWJSU56XRR+gub6k8Jcw7+cBOLoOuX3HCFxJN1UKLJHiDmO12puEAPkrJXiignP8gk+IZ6qEo0ySglGAkS5VSCkChltuY+Nri8M/d8942ll+kI6J8LPARGzx76T1lJnIdT0+S9mWMGd0G8CCg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789213728; c=relaxed/simple; bh=uiM6qpZSalopRnKCWl7CZVrbs1seGay9787WxjARQkg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MuG5uvXrjjJ7EqtJKKWVMPB1HFTyRr3fQv5dpavX4ApF2Zxf2MeKLQthSp6GNEYkGm8BiYrLifLLh/7KTIInjqAXhrR4Pex2/jwhzHLTh0jOwCzYbVy+zkx6/c3rR6HxKGVnxccUam3b4+IY+qYTrpglu4waiLa9H89lLv0AHcw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Kw/tMOla; 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="Kw/tMOla" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29AD31F00893; Sat, 12 Sep 2026 11:48:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789213727; bh=exqMFh5Q0j8AuR3NXSgM5soBCSi5+V8c3znc+xXTbBg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Kw/tMOlaYc2wmRccqkx17dmj1xDmSK3VrcnXTQUPE5RLgw2ybDNcoKz5iizTQwB4s FnwsHS1YbDaEV/KZep1EulLV+uNTZK7cN1NVpJ7cFJC1ePESNuCeWdB5tDi7gQb0GL F4xUR2nOXi3HFaB7hK1qVGa22AphlRpDdEBD9/SY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hans Verkuil , Valery Borovsky Subject: [PATCH 6.12 0179/1376] media: airspy: use vb2_video_unregister_device() on disconnect to fix NULL deref Date: Sat, 12 Sep 2026 08:43:25 +0200 Message-ID: <20260912065611.540855320@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: Valery Borovsky commit 2f378dc45e685fc825d2dd08e7864666d6fcc009 upstream. airspy_disconnect() clears s->udev under v4l2_lock, but airspy_stop_streaming() unconditionally calls airspy_ctrl_msg() and airspy_free_stream_bufs() afterwards. If a streaming user closes the device after disconnect, stop_streaming() runs and dereferences the NULL s->udev: airspy_stop_streaming() airspy_ctrl_msg(s, CMD_RECEIVER_MODE, 0, 0, NULL, 0) usb_sndctrlpipe(s->udev, 0) /* NULL deref */ airspy_free_stream_bufs(s) usb_free_coherent(s->udev, ...) /* NULL deref */ The airspy driver uses vb2_fop_release() in its file_operations, so replace video_unregister_device(&s->vdev) with vb2_video_unregister_device(&s->vdev) and move it before clearing s->udev. vb2_video_unregister_device() releases the vb2 queue, which synchronously runs airspy_stop_streaming() if streaming is active, so the URBs, coherent DMA stream buffers and the hardware stop control message all execute while s->udev is still valid. vb2_video_unregister_device() locks vdev->queue->lock (vb_queue_lock) internally, and stop_streaming() locks v4l2_lock, so the previous outer mutex_lock(&s->vb_queue_lock) / mutex_lock(&s->v4l2_lock) pair around the unregister sequence would self-deadlock and has been removed. A short v4l2_lock critical section around s->udev = NULL remains so any ioctl path that still holds the file descriptor sees coherent state. Issue identified by automated review of the INV-003 series at https://sashiko.dev/ Fixes: 634fe5033951 ("[media] airspy: AirSpy SDR driver") Cc: stable@vger.kernel.org Suggested-by: Hans Verkuil Signed-off-by: Valery Borovsky Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/airspy/airspy.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) --- a/drivers/media/usb/airspy/airspy.c +++ b/drivers/media/usb/airspy/airspy.c @@ -464,14 +464,21 @@ static void airspy_disconnect(struct usb dev_dbg(s->dev, "\n"); - mutex_lock(&s->vb_queue_lock); + /* + * vb2_video_unregister_device() releases the vb2 queue, which + * triggers airspy_stop_streaming() if streaming is active. + * stop_streaming() dereferences s->udev via airspy_ctrl_msg() and + * airspy_free_stream_bufs(), so it must run before s->udev is + * cleared. vb2_video_unregister_device() locks vb_queue_lock + * internally and stop_streaming() locks v4l2_lock, so neither may + * be held by the caller. + */ + v4l2_device_disconnect(&s->v4l2_dev); + vb2_video_unregister_device(&s->vdev); + mutex_lock(&s->v4l2_lock); - /* No need to keep the urbs around after disconnection */ s->udev = NULL; - v4l2_device_disconnect(&s->v4l2_dev); - video_unregister_device(&s->vdev); mutex_unlock(&s->v4l2_lock); - mutex_unlock(&s->vb_queue_lock); v4l2_device_put(&s->v4l2_dev); }