7.5

CVE-2021-47559: net/smc: Fix NULL pointer dereferencing in smc_vlan_by_tcpsk()

Modified
AliasesUBUNTU-CVE-2021-47559DEBIAN-CVE-2021-47559
Published 24-05-2024Last modified 05-08-2026

Vulnerability summary

CVE-2021-47559 is a high (CVSS 7.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.47% chance of exploitation in the next 30 days, higher than 40.5% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.47%
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 10 · Related 8
RHSA-2024:6990RHSA-2024:6991SUSE-SU-2024:2008-1SUSE-SU-2024:2011-1SUSE-SU-2024:2019-1SUSE-SU-2024:2189-1

Timeline

  1. 24-05-2024
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: net/smc: Fix NULL pointer dereferencing in smc_vlan_by_tcpsk() Coverity reports a possible NULL dereferencing problem: in smc_vlan_by_tcpsk(): 6. returned_null: netdev_lower_get_next returns NULL (checked 29 out of 30 times). 7. var_assigned: Assigning: ndev = NULL return value from netdev_lower_get_next. 1623 ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower); CID 1468509 (#1 of 1): Dereference null return value (NULL_RETURNS) 8. dereference: Dereferencing a pointer that might be NULL ndev when calling is_vlan_dev. 1624 if (is_vlan_dev(ndev)) { Remove the manual implementation and use netdev_walk_all_lower_dev() to iterate over the lower devices. While on it remove an obsolete function parameter comment.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.47%

Chance of exploitation in the next 30 days

Percentile

41%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.47% 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: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu86 products
  • linuxAll versions (No fix recorded)
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ cb9d43f6775457cac75544bc4197f26ac2b6f294, < c94cbd262b6aa3b54d73a1ed1f9c0d19df57f4ff | ≥ cb9d43f6775457cac75544bc4197f26ac2b6f294, < bb851d0fb02547d03cd40106b5f2391c4fed6ed1 | ≥ cb9d43f6775457cac75544bc4197f26ac2b6f294, < 587acad41f1bc48e16f42bb2aca63bf323380be8 | 4.18
  • linux_kernel≥ 4.18, < 5.10.83 | ≥ 5.11, < 5.15.6
Debian1 product
  • linux< 5.15.15-1

3 vendors · 89 products

References

7 links