5.5

CVE-2021-47439: net: dsa: microchip: Added the condition for scheduling ksz_mib_read_work

Analyzed
AliasesUBUNTU-CVE-2021-47439DEBIAN-CVE-2021-47439
Published 22-05-2024Last modified 11-05-2026

Vulnerability summary

CVE-2021-47439 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 13.2% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.22%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 5 · Related 5
SUSE-SU-2024:2008-1SUSE-SU-2024:2011-1SUSE-SU-2024:2019-1SUSE-SU-2024:2189-1SUSE-SU-2024:2190-1

Timeline

  1. 22-05-2024
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

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

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.22%

Chance of exploitation in the next 30 days

Percentile

13%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.22% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu62 products
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
  • linux-aws-5.13All versions (No fix recorded)
  • linux-aws-5.19All versions (No fix recorded)
Linux2 products
  • linux≥ 469b390e1ba330e888175e55d78573db2e9a8cb4, < f2e1de075018cf71bcd7d628e9f759cb8540b0c3 | ≥ 469b390e1ba330e888175e55d78573db2e9a8cb4, < 383239a33cf29ebee9ce0d4e0e5c900b77a16148 | ≥ 469b390e1ba330e888175e55d78573db2e9a8cb4, < ef1100ef20f29aec4e62abeccdb5bdbebba1e378 | 5.7
  • linux_kernel≥ 5.7, < 5.10.75 | ≥ 5.11, < 5.14.14 | 5.15:rc1 | 5.15:rc2 | 5.15:rc3 | 5.15:rc4 | 5.15:rc5
Debian1 product
  • linux< 5.14.16-1

3 vendors · 65 products

References

7 links