What is CVE-2021-46942?

CVE-2021-46942 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 5.12 onward and patched in 5.12.3 and 5.13. CVE-2021-46942 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-46942?

CVE-2021-46942 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2021-46942?

Yes, CVE-2021-46942 has been patched. Fixed versions include 5.12.3 and 5.13. If you are running Linux kernel 5.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-46942 actively exploited?

CVE-2021-46942 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2021-46942

Medium

In the Linux kernel, the following vulnerability has been resolved: io_uring: fix shared sqpoll cancellation hangs [ 736.982891] INFO: task iou-sqp-4294:4295 blocked for more than 122 seconds. [ 736.982897] Call Trace: [ 736.982901] schedule+0x68/0xe0 [ 736.982903] io_uring_cancel_sqpoll+0xdb/0x110 [ 736.982908] io_sqpoll_cancel_cb+0x24/0x30 [ 736.982911] io_run_task_work_head+0x28/0x50 [ 736.982913] io_sq_thread+0x4e3/0x720 We call io_uring_cancel_sqpoll() one by one for each ctx either in sq_thread() itself or via task works, and it's intended to cancel all requests of a specified context. However the function uses per-task counters to track the number of inflight requests, so it counts more requests than available via currect io_uring ctx and goes to sleep for them to appear (e.g. from IRQ), that will never happen. Cancel a bit more than before, i.e. all ctxs that share sqpoll and continue to use shared counters. Don't forget that we should not remove ctx from the list before running that task_work sqpoll-cancel, otherwise the function wouldn't be able to find the context and will hang.

Package Linux Kernel

Published 2024-02-27

Last modified 2024-11-21

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Affected versions

Linux kernel versions 5.12 and later are affected. Fixed in 5.12.3, 5.13 and their respective stable series.

Affected from

≥ 5.12

Fixed in

✓ 5.12.3 5.12.x ✓ 5.13

References

2 total

Kernel Git
https://git.kernel.org/stable/c/734551df6f9bedfbefcd113ede665945e9de0b99

Patch
Kernel Git
https://git.kernel.org/stable/c/cb5e0b3d0f993a6268c1a2c7ede2f9aa0c17ef68

Patch

Details

CVE ID CVE-2021-46942

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-02-27

Modified 2024-11-21

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-46942?

CVE-2021-46942 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 5.12 onward and has been patched in 5.12.3 and 5.13. CVE-2021-46942 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-46942?

CVE-2021-46942 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2021-46942?

Yes. CVE-2021-46942 has been patched. Fixed versions include 5.12.3 and 5.13. If you are running Linux kernel 5.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-46942 actively exploited?

No. CVE-2021-46942 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.