CVE-2026-89880

In the Linux kernel, the following vulnerability has been resolved:

media: rtl2832_sdr: release URBs and stream buffers on start_streaming() failure

rtl2832_sdr_start_streaming() calls rtl2832_sdr_alloc_stream_bufs(), rtl2832_sdr_alloc_urbs() and rtl2832_sdr_submit_urbs() in sequence and shares a single err: label that only unlocks the mutex and returns. When alloc_urbs() succeeds but submit_urbs() fails, or when alloc_urbs() itself returns -ENOMEM after alloc_stream_bufs() has already succeeded, the URBs and/or the coherent DMA stream buffers stay allocated while streaming reports failure to vb2. Two latent defects follow on the next VIDIOC_STREAMON:

1. rtl2832_sdr_alloc_stream_bufs() unconditionally resets dev->buf_num to 0 and overwrites dev->buf_list[]/dev->dma_addr[], permanently leaking the coherent DMA memory allocated by the previous attempt.

2. rtl2832_sdr_alloc_urbs() never resets dev->urbs_initialized and only increments it. After a second successful pass urbs_initialized can exceed MAX_BULK_BUFS, so the subsequent rtl2832_sdr_free_urbs() walks from urbs_initialized - 1 down to 0 and reads past the end of dev->urb_list[], passing garbage pointers to usb_free_urb().

Mirror the teardown that stop_streaming() already performs: on the error path call rtl2832_sdr_free_urbs() and rtl2832_sdr_free_stream_bufs() before unlocking. Both helpers are idempotent (free_urbs kills and zeros urbs_initialized; free_stream_bufs is gated on URB_BUF and clears the buf_num counter), so partial-failure paths and the no-allocation paths remain safe.

Issue identified by automated review of the INV-003 series at https://sashiko.dev/

Affected Software

References

• https://git.kernel.org/stable/c/0337ab0759285076a3f9dcfcc40906e69ab519b3
• https://git.kernel.org/stable/c/26a2a985bbeee3eaa6f80ff7de732161a171ec9f
• https://git.kernel.org/stable/c/8bcf11a239eac4e224ad856277de9a36c91b1711
• https://git.kernel.org/stable/c/ac02b2c56ccef0788cea9b86990a8f349a3fc6d8
• https://git.kernel.org/stable/c/c819dea3a433ae790b829443fdcc1715d1586560
• https://git.kernel.org/stable/c/c91e8ae2b39c6da81f26f2c9877d3fd33a4465ce
• https://git.kernel.org/stable/c/f14a713a36a5c87568430e9770896f2a8f5bbbb7
• https://git.kernel.org/stable/c/fe50cdaebf12cd32ff9a44d92bfd6fbc2300dbd4