CVE-2024-44968: tick/broadcast: Move per CPU pointer access into the atomic section

Severity: medium (CVSS 5.5 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: 2024-09-04 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: tick/broadcast: Move per CPU pointer access into the atomic section The recent fix for making the take over of the broadcast timer more reliable retrieves a per CPU pointer in preemptible context. This went unnoticed as compilers hoist the access into the non-preemptible region where the pointer is actually used. But of course it's valid that the compiler keeps it at the place where the code puts it which rightfully triggers: BUG: using smp_processor_id() in preemptible [00000000] code: caller is hotplug_cpu__broadcast_tick_pull+0x1c/0xc0 Move it to the actual usage site which is in a non-preemptible region.

Affected products

Linux kernel: from 6.1.103 before 6.1.105; from 6.6.44 before 6.6.46; from 6.10.3 before 6.10.5; 6.11-rc1 — fixed in 6.1.105, 6.10.5, 6.6.46

How to fix

Upgrade to a fixed version: Linux kernel 6.1.105, 6.10.5, 6.6.46. Check the vendor advisory for mitigations.

References

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