CVE-2022-48636: s390/dasd: fix Oops in dasd_alias_get_start_dev due to missing pavgroup

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-04-28 · updated 2026-08-04
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: s390/dasd: fix Oops in dasd_alias_get_start_dev due to missing pavgroup Fix Oops in dasd_alias_get_start_dev() function caused by the pavgroup pointer being NULL. The pavgroup pointer is checked on the entrance of the function but without the lcu->lock being held. Therefore there is a race window between dasd_alias_get_start_dev() and _lcu_update() which sets pavgroup to NULL with the lcu->lock held. Fix by checking the pavgroup pointer with lcu->lock held.

Affected products

Linux kernel: from 2.6.25 before 4.9.330; from 4.10 before 4.14.295; from 4.15 before 4.19.260; from 4.20 before 5.4.215; from 5.5 before 5.10.146; from 5.11 before 5.15.71 — fixed in 4.14.295, 4.19.260, 4.9.330, 5.10.146, 5.15.71, 5.19.12

How to fix

Upgrade to a fixed version: Linux kernel 4.14.295, 4.19.260, 4.9.330, 5.10.146. Check the vendor advisory for mitigations.

References

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