What is CVE-2021-47163?

CVE-2021-47163 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, classified as a Improper Locking flaw (CWE-667), affecting Linux kernel versions from 4.1 onward and patched in 5.4.124, 5.10.42, 5.12.9 and others. CVE-2021-47163 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47163?

CVE-2021-47163 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-2021-47163?

Yes, CVE-2021-47163 has been patched. Fixed versions include 5.4.124, 5.10.42, 5.12.9 and others. If you are running Linux kernel 4.1 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47163 actively exploited?

CVE-2021-47163 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Improper Locking (CWE-667)?

The product does not properly acquire or release a lock, which can lead to unexpected behaviour. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/667.html

CVE-2021-47163

Medium

In the Linux kernel, the following vulnerability has been resolved: tipc: wait and exit until all work queues are done On some host, a crash could be triggered simply by repeating these commands several times: # modprobe tipc # tipc bearer enable media udp name UDP1 localip 127.0.0.1 # rmmod tipc [] BUG: unable to handle kernel paging request at ffffffffc096bb00 [] Workqueue: events 0xffffffffc096bb00 [] Call Trace: [] ? process_one_work+0x1a7/0x360 [] ? worker_thread+0x30/0x390 [] ? create_worker+0x1a0/0x1a0 [] ? kthread+0x116/0x130 [] ? kthread_flush_work_fn+0x10/0x10 [] ? ret_from_fork+0x35/0x40 When removing the TIPC module, the UDP tunnel sock will be delayed to release in a work queue as sock_release() can't be done in rtnl_lock(). If the work queue is schedule to run after the TIPC module is removed, kernel will crash as the work queue function cleanup_beareri() code no longer exists when trying to invoke it. To fix it, this patch introduce a member wq_count in tipc_net to track the numbers of work queues in schedule, and wait and exit until all work queues are done in tipc_exit_net().

Package Linux Kernel

Published 2024-03-25

Last modified 2025-03-13

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

Weakness type

CWE-667

CVE-2021-47163 is a Improper Locking vulnerability

What is Improper Locking?

The product does not properly acquire or release a lock, which can lead to unexpected behaviour. Learn more on MITRE CWE

Affected versions

Linux kernel versions 4.1 and later are affected. Fixed in 5.4.124, 5.10.42, 5.12.9, 5.13 and their respective stable series.

Affected from

≥ 4.1

Fixed in

✓ 5.4.124 5.4.x ✓ 5.10.42 5.10.x ✓ 5.12.9 5.12.x ✓ 5.13

References

4 total

Kernel Git
https://git.kernel.org/stable/c/04c26faa51d1e2fe71cf13c45791f5174c37f986

Patch
Kernel Git
https://git.kernel.org/stable/c/5195ec5e365a2a9331bfeb585b613a6e94f98dba

Patch
Kernel Git
https://git.kernel.org/stable/c/b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d

Patch
Kernel Git
https://git.kernel.org/stable/c/d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa

Patch

Details

CVE ID CVE-2021-47163

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-03-25

Modified 2025-03-13

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47163?

CVE-2021-47163 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Improper Locking flaw (CWE-667) . It affects Linux kernel versions from 4.1 onward and has been patched in 5.4.124, 5.10.42, 5.12.9 and others. CVE-2021-47163 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47163?

CVE-2021-47163 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-2021-47163?

Yes. CVE-2021-47163 has been patched. Fixed versions include 5.4.124, 5.10.42, 5.12.9 and others. If you are running Linux kernel 4.1 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47163 actively exploited?

No. CVE-2021-47163 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.