CVE-2025-71129: LoongArch: BPF: Sign extend kfunc call arguments

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-01-14 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: LoongArch: BPF: Sign extend kfunc call arguments The kfunc calls are native calls so they should follow LoongArch calling conventions. Sign extend its arguments properly to avoid kernel panic. This is done by adding a new emit_abi_ext() helper. The emit_abi_ext() helper performs extension in place meaning a value already store in the target register (Note: this is different from the existing sign_extend() helper and thus we can't reuse it).

Affected products

Linux kernel: from 6.1.1 before 6.6.120; from 6.7 before 6.12.64; from 6.13 before 6.18.4; 6.1, 6.19-rc1, 6.19-rc2, 6.19-rc3, 6.19-rc4, 6.19-rc5 (+3) — fixed in 6.12.64, 6.18.4, 6.6.120

How to fix

Upgrade to a fixed version: Linux kernel 6.12.64, 6.18.4, 6.6.120. Check the vendor advisory for mitigations.

References

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