CVE-2025-22048: In the Linux kernel, the following vulnerability has been resolved: LoongArch: BPF: Don't override subprog's return value The verifier test `calls: ...

Description

In the Linux kernel, the following vulnerability has been resolved: LoongArch: BPF: Don't override subprog's return value The verifier test `calls: div by 0 in subprog` triggers a panic at the ld.bu instruction. The ld.bu insn is trying to load byte from memory address returned by the subprog. The subprog actually set the correct address at the a5 register (dedicated register for BPF return values). But at commit 73c359d1d356 ("LoongArch: BPF: Sign-extend return values") we also sign extended a5 to the a0 register (return value in LoongArch). For function call insn, we later propagate the a0 register back to a5 register. This is right for native calls but wrong for bpf2bpf calls which expect zero-extended return value in a5 register. So only move a0 to a5 for native calls (i.e. non-BPF_PSEUDO_CALL).

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.17%

6.1th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	>= 6.1.120, < 6.2
Linux	Linux Kernel	>= 6.6.64, < 6.6.87
Linux	Linux Kernel	>= 6.11.11, < 6.12
Linux	Linux Kernel	>= 6.12.2, < 6.12.23
Linux	Linux Kernel	>= 6.13, < 6.13.11
Linux	Linux Kernel	>= 6.14, < 6.14.2

References

Timeline

Published: Apr 16, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-22048?

In the Linux kernel, the following vulnerability has been resolved: LoongArch: BPF: Don't override subprog's return value The verifier test `calls: div by 0 in subprog` triggers a panic at the ld.bu instruction. The ld.bu insn is trying to load byte from memory address returned by the subprog. The subprog actually set the correct address at the a5 register (dedicated register for BPF return values). But at commit 73c359d1d356 ("LoongArch: BPF: Sign-extend return values") we also sign extended a5 to the a0 register (return value in LoongArch). For function call insn, we later propagate the a0 register back to a5 register. This is right for native calls but wrong for bpf2bpf calls which expect zero-extended return value in a5 register. So only move a0 to a5 for native calls (i.e. non-BPF_PSEUDO_CALL).

How severe is CVE-2025-22048?

CVE-2025-22048 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.

How do I fix CVE-2025-22048?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.