CVE-2024-56768: bpf: Fix bpf_get_smp_processor_id() on !CONFIG_SMP

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: 2025-01-06 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix bpf_get_smp_processor_id() on !CONFIG_SMP On x86-64 calling bpf_get_smp_processor_id() in a kernel with CONFIG_SMP disabled can trigger the following bug, as pcpu_hot is unavailable: [ 8.471774] BUG: unable to handle page fault for address: 00000000936a290c [ 8.471849] #PF: supervisor read access in kernel mode [ 8.471881] #PF: error_code(0x0000) - not-present page Fix by inlining a return 0 in the !CONFIG_SMP case.

Affected products

Linux kernel: from 6.10 before 6.12.8; 6.13-rc1, 6.13-rc2, 6.13-rc3 — fixed in 6.12.8

How to fix

Upgrade to a fixed version: Linux kernel 6.12.8. Check the vendor advisory for mitigations.

References

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