CVE-2023-23586 Use after free in io_uring in the Linux Kernel

2023-02-1712:25:35

CWE-416

Google

www.cve.org

linux kernel

vulnerability

memory leak

5.5 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

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

6.3 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

9.1%

JSON

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

CNA Affected

[
  {
    "defaultStatus": "unaffected",
    "packageName": "kernel",
    "product": "Linux Kernel",
    "repo": "https://git.kernel.org",
    "vendor": "Linux",
    "versions": [
      {
        "lessThanOrEqual": "5.10.161",
        "status": "affected",
        "version": "5.6",
        "versionType": "custom"
      }
    ]
  }
]