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
Awaiting data

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

References

The following references provide additional information about CVE-2021-47163 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

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) . 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?

    No patch is currently available for CVE-2021-47163. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

  • 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.

  • What is Improper Locking (CWE-667)?

    The product does not properly acquire or release a lock, which can lead to unexpected behaviour. View CWE-667 on MITRE CWE →