SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2022-3176

There exists a use-after-free in io_uring in the Linux kernel.

HIGH 7.8EPSS 0.29%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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

CVSS 3.1
7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.29% probability · 22th percentile
CISA KEV
Not listed
Weakness
CWE-416
Affected
linux/linux kernel · debian/debian linux
Source
cve-coordination@google.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.