CVE-2026-63823

Summary

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.]

Impact & exploitability

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products we track (1)

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://git.kernel.org/stable/c/35ab4db86774d82389e4b9559e26ab7f68d8e395 ↗

Additional information

• NVD record
• https://git.kernel.org/stable/c/35ab4db86774d82389e4b9559e26ab7f68d8e395Patch
• https://git.kernel.org/stable/c/4982bfabce6b33b3c9eddb4fb900fe5568b7cf91Patch
• https://git.kernel.org/stable/c/708709c65a1832a99b0eef8ae46e343ddaca3d06Patch
• https://git.kernel.org/stable/c/7216ce8cb12fee44e309503955bb83806b106129Patch
• https://git.kernel.org/stable/c/83c0a1cb296d955d5f4d1f0bd8a769ba8ed8c29fPatch
• https://git.kernel.org/stable/c/d8274181b0f28d450b42489723a5ba81042158d7Patch
• https://git.kernel.org/stable/c/f9b68632ac93cc742f2e411021c4dbfe452ea0c2Patch
• https://git.kernel.org/stable/c/fd15b457a86939c38aa12116adabd8ff686c5e51Patch