CVE-2022-3176 Use-after-free in io_uring in Linux Kernel

2022-09-1613:55:09

CWE-416

Google

www.cve.org

linux kernel

use-after-free

io_uring

signalfd_poll

binder_poll

waitqueue

pollfree

upgrade

commit

vulnerability

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

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

AI Score

7.7

Confidence

High

EPSS

Percentile

14.2%

JSON

There exists a use-after-free in io_uring in the Linux kernel. Signalfd_poll() and binder_poll() use a waitqueue whose lifetime is the current task. It will send a POLLFREE notification to all waiters before the queue is freed. Unfortunately, the io_uring poll doesn’t handle POLLFREE. This allows a use-after-free to occur if a signalfd or binder fd is polled with io_uring poll, and the waitqueue gets freed. We recommend upgrading past commit fc78b2fc21f10c4c9c4d5d659a685710ffa63659

CNA Affected

[
  {
    "vendor": "Linux",
    "product": "Kernel",
    "versions": [
      {
        "version": "unspecified",
        "lessThan": "fc78b2fc21f10c4c9c4d5d659a685710ffa63659",
        "status": "affected",
        "versionType": "custom"
      }
    ]
  }
]