CVE-2026-63823
Published: July 22, 2026Last modified: July 22, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: keys: Pin request_key_auth payload in instantiate paths A: request_key() B: KEYCTL_INSTANTIATE_IOV ================ ========================= create auth key store rka in auth key wait for helper get auth key load rka from auth key copy user payload sleep on #PF helper completed detach and free rka destroy auth key wake up use rka->target_key **USE-AFTER-FREE** Give request_key_auth payloads a refcount. Take a payload reference while authkey->sem stabilizes the payload and revocation state. Hold that reference across the instantiate and reject paths. Drop the auth key owning reference from revoke and destroy. [jarkko: Replaced the first two paragraphs of text with an actual concurrency scenario.]
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.8 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.177-r0) |
| 25 LTS | linux-lts | Fixed (6.12.95-r0) | |
| Stream | linux-lts | Fixed (6.18.38-r0) |
References
- https://git.kernel.org/stable/c/35ab4db86774d82389e4b9559e26ab7f68d8e395
- https://git.kernel.org/stable/c/4982bfabce6b33b3c9eddb4fb900fe5568b7cf91
- https://git.kernel.org/stable/c/708709c65a1832a99b0eef8ae46e343ddaca3d06
- https://git.kernel.org/stable/c/7216ce8cb12fee44e309503955bb83806b106129
- https://git.kernel.org/stable/c/83c0a1cb296d955d5f4d1f0bd8a769ba8ed8c29f
- https://git.kernel.org/stable/c/d8274181b0f28d450b42489723a5ba81042158d7
- https://git.kernel.org/stable/c/f9b68632ac93cc742f2e411021c4dbfe452ea0c2
- https://git.kernel.org/stable/c/fd15b457a86939c38aa12116adabd8ff686c5e51