Vulnerability Description
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 time namespace is destroyed, the vvar page is also freed, but not removed from the process' memory, and a next page allocated by the kernel will be still available from the user-space process and can leak memory contents via this (read-only) use-after-free vulnerability. We recommend upgrading past version 5.10.161 or commit 788d0824269bef539fe31a785b1517882eafed93 https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/io_uring
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 5.6, < 5.10.161 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/io_uringMailing ListPatch
- https://kernel.dance/#788d0824269bef539fe31a785b1517882eafed93Patch
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/io_uringMailing ListPatch
- https://kernel.dance/#788d0824269bef539fe31a785b1517882eafed93Patch
FAQ
What is CVE-2023-23586?
CVE-2023-23586 is a vulnerability with a CVSS score of 5.5 (MEDIUM). 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 proc...
How severe is CVE-2023-23586?
CVE-2023-23586 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2023-23586?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.