In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
media: rtl2832_sdr: use vb2_video_unregister_device() on remove to fix DMA leak<\/p>\n
rtl2832_sdr_remove() runs on USB disconnect and clears dev->udev to
\nNULL before any pending streaming teardown has run. When user space
\nlater closes its file descriptor, vb2 calls rtl2832_sdr_stop_streaming()
\nwhich in turn calls rtl2832_sdr_free_stream_bufs(). That helper releases
\neach coherent buffer with:<\/p>\n
usb_free_coherent(dev->udev, dev->buf_size,
\n dev->buf_list[dev->buf_num],
\n dev->dma_addr[dev->buf_num]);<\/p>\n
usb_free_coherent() returns immediately when its dev argument is NULL,
\nso every DMA stream buffer that was live at disconnect is silently
\nleaked. The URBs allocated in rtl2832_sdr_alloc_urbs() outlive the
\ndevice for the same reason.<\/p>\n
The rtl2832_sdr driver uses vb2_fop_release() in its file_operations,
\nso replace video_unregister_device(&dev->vdev) with
\nvb2_video_unregister_device(&dev->vdev) and move it before clearing
\ndev->udev. vb2_video_unregister_device() releases the vb2 queue, which
\nsynchronously runs rtl2832_sdr_stop_streaming() if streaming is active,
\nso URBs and coherent DMA stream buffers are freed while dev->udev is
\nstill valid.<\/p>\n
vb2_video_unregister_device() locks vdev->queue->lock (vb_queue_lock)
\ninternally, and stop_streaming() locks v4l2_lock, so the previous outer
\nmutex_lock(&dev->vb_queue_lock) \/ mutex_lock(&dev->v4l2_lock) pair
\naround the unregister sequence would self-deadlock and has been removed.
\nA short v4l2_lock critical section around dev->udev = NULL remains so
\nany ioctl path that still holds the file descriptor sees coherent state.<\/p>\n
Issue identified by automated review of the INV-003 series at
\nhttps:\/\/sashiko.dev\/<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
media: rtl2832_sdr: use vb2_video_unregister_device() on remove to fix DMA leak<\/p>\n
rtl2832_sdr_remove() runs on USB disconnect and cl<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-24568","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/24568","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=24568"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=24568"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=24568"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}