CVE-2023-23586 — Due to a vulnerability in the io_uring subsystem, it is possible to leak kernel

Due to a vulnerability in the io_uring subsystem, it is possible to leak kernel memory information to the user process. timens_install calls current_is_single_threaded to determine if the current process is single-threaded, but this call does not consider io_uring's io_worke

01What is this vulnerability?

Due to a vulnerability in the io_uring subsystem, it is possible to leak kernel memory information to the user process. timens_install calls current_is_single_threaded to determine if the current process is single-threaded, but this call does not consider io_uring's io_worker threads, thus it is possible to insert a time namespace's vvar page to process's memory space via a page fault. When this…

02Affected products

Vendor	Product	Versions
Linux	Linux Kernel	5.6

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-02-17T12:25:35.000Z
• Last modified: 2025-03-12T20:08:30.870Z

09References

• git.kernel.org — https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/io_uring…
• kernel.dance — https://kernel.dance/#788d0824269bef539fe31a785b1517882eafed93