CVE-2021-47439
net: dsa: microchip: Added the condition for scheduling ksz_mib_read_work
Description
In the Linux kernel, the following vulnerability has been resolved: net: dsa: microchip: Added the condition for scheduling ksz_mib_read_work When the ksz module is installed and removed using rmmod, kernel crashes with null pointer dereferrence error. During rmmod, ksz_switch_remove function tries to cancel the mib_read_workqueue using cancel_delayed_work_sync routine and unregister switch from dsa. During dsa_unregister_switch it calls ksz_mac_link_down, which in turn reschedules the workqueue since mib_interval is non-zero. Due to which queue executed after mib_interval and it tries to access dp->slave. But the slave is unregistered in the ksz_switch_remove function. Hence kernel crashes. To avoid this crash, before canceling the workqueue, resetted the mib_interval to 0. v1 -> v2: -Removed the if condition in ksz_mib_read_work
INFO
Published Date :
May 22, 2024, 7:15 a.m.
Last Modified :
April 2, 2025, 3:14 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update the Linux kernel to a patched version.
- Reboot the system after the update.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-47439.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47439 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47439
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-47439 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47439 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Apr. 02, 2025
Action Type Old Value New Value Added CWE CWE-476 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.14.14 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.7 up to (excluding) 5.10.75 Added Reference Type CVE: https://git.kernel.org/stable/c/383239a33cf29ebee9ce0d4e0e5c900b77a16148 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/383239a33cf29ebee9ce0d4e0e5c900b77a16148 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/ef1100ef20f29aec4e62abeccdb5bdbebba1e378 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/ef1100ef20f29aec4e62abeccdb5bdbebba1e378 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/f2e1de075018cf71bcd7d628e9f759cb8540b0c3 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/f2e1de075018cf71bcd7d628e9f759cb8540b0c3 Types: Patch -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/383239a33cf29ebee9ce0d4e0e5c900b77a16148 Added Reference https://git.kernel.org/stable/c/ef1100ef20f29aec4e62abeccdb5bdbebba1e378 Added Reference https://git.kernel.org/stable/c/f2e1de075018cf71bcd7d628e9f759cb8540b0c3 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 31, 2024
Action Type Old Value New Value Added CVSS V3.1 CISA-ADP AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 22, 2024
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: net: dsa: microchip: Added the condition for scheduling ksz_mib_read_work When the ksz module is installed and removed using rmmod, kernel crashes with null pointer dereferrence error. During rmmod, ksz_switch_remove function tries to cancel the mib_read_workqueue using cancel_delayed_work_sync routine and unregister switch from dsa. During dsa_unregister_switch it calls ksz_mac_link_down, which in turn reschedules the workqueue since mib_interval is non-zero. Due to which queue executed after mib_interval and it tries to access dp->slave. But the slave is unregistered in the ksz_switch_remove function. Hence kernel crashes. To avoid this crash, before canceling the workqueue, resetted the mib_interval to 0. v1 -> v2: -Removed the if condition in ksz_mib_read_work Added Reference kernel.org https://git.kernel.org/stable/c/f2e1de075018cf71bcd7d628e9f759cb8540b0c3 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/383239a33cf29ebee9ce0d4e0e5c900b77a16148 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/ef1100ef20f29aec4e62abeccdb5bdbebba1e378 [No types assigned]