5.5

CVE-2021-47369: s390/qeth: fix NULL deref in qeth_clear_working_pool_list()

Analyzed
AliasesUBUNTU-CVE-2021-47369DEBIAN-CVE-2021-47369
Published 21-05-2024Last modified 23-05-2026

Vulnerability summary

CVE-2021-47369 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 15% 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
0.24%
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 11 · Related 11
SUSE-SU-2024:1979-1SUSE-SU-2024:1983-1SUSE-SU-2024:2008-1SUSE-SU-2024:2010-1SUSE-SU-2024:2011-1SUSE-SU-2024:2019-1

Timeline

  1. 21-05-2024
    PublishedVulnerability first disclosed.
  2. 23-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: s390/qeth: fix NULL deref in qeth_clear_working_pool_list() When qeth_set_online() calls qeth_clear_working_pool_list() to roll back after an error exit from qeth_hardsetup_card(), we are at risk of accessing card->qdio.in_q before it was allocated by qeth_alloc_qdio_queues() via qeth_mpc_initialize(). qeth_clear_working_pool_list() then dereferences NULL, and by writing to queue->bufs[i].pool_entry scribbles all over the CPU's lowcore. Resulting in a crash when those lowcore areas are used next (eg. on the next machine-check interrupt). Such a scenario would typically happen when the device is first set online and its queues aren't allocated yet. An early IO error or certain misconfigs (eg. mismatched transport mode, bad portno) then cause us to error out from qeth_hardsetup_card() with card->qdio.in_q still being NULL. Fix it by checking the pointer for NULL before accessing it. Note that we also have (rare) paths inside qeth_mpc_initialize() where a configuration change can cause us to free the existing queues, expecting that subsequent code will allocate them again. If we then error out before that re-allocation happens, the same bug occurs. Root-caused-by: Heiko Carstens <hca@linux.ibm.com>

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.24%

Chance of exploitation in the next 30 days

Percentile

15%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.24% 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≥ eff73e16ee116f6eafa2be48fab42659a27cb453, < db94f89e1dadf693c15c2d60de0c34777cea5779 | ≥ eff73e16ee116f6eafa2be48fab42659a27cb453, < 9b00fb12cdc9d8d1c3ffe82a78e74738127803fc | ≥ eff73e16ee116f6eafa2be48fab42659a27cb453, < 248f064af222a1f97ee02c84a98013dfbccad386 | b2400fe7e1011c5f3dc2268e8382082465b1c8a2 | 22697ca855c06a4a1264d5651542b7d98870a8c4 | ≥ 5.7.16, < 5.8 | ≥ 5.8.2, < 5.9 | 5.9
  • linux_kernel≥ 5.7.16, < 5.8 | ≥ 5.8.2, < 5.10.70 | ≥ 5.11, < 5.14.9 | 5.15:rc1 | 5.15:rc2
Debian1 product
  • linux< 5.14.9-1

3 vendors · 65 products

References

7 links