CVE-2025-38339

CVE-2025-38339 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: powerpc/bpf: fix JIT code size calculation of bpf trampoline arch_bpf_trampoline_size() provides JIT size of the BPF trampoline before the buffer for JIT'ing it is allocated. The total number of instructions emitted for BPF trampoline JIT code depends on where the final image is located. So, the size arrived at with the dummy pass in arch_bpf_trampoline_size() can vary from the actual size needed in arch_prepare_bpf_trampoline(). When the instructions accounted in arch_bpf_trampoline_size() is less than the number of instructions emitted during the actual JIT compile of the trampoline, the below warning is produced: WARNING: CPU: 8 PID: 204190 at arch/powerpc/net/bpf_jit_comp.c:981 __arch_prepare_bpf_trampoline.isra.0+0xd2c/0xdcc which is: /* Make sure the trampoline generation logic doesn't overflow */ if (image && WARN_ON_ONCE(&image[ctx->idx] > (u32 *)rw_image_end - BPF_INSN_SAFETY)) { So, during the dummy pass, instead of providing some arbitrary image location, account for maximum possible instructions if and when there is a dependency with image location for JIT'ing.

Frequently asked questions

What is CVE-2025-38339?
In the Linux kernel, the following vulnerability has been resolved: powerpc/bpf: fix JIT code size calculation of bpf trampoline arch_bpf_trampoline_size() provides JIT size of the BPF trampoline before the buffer for JIT'ing it is allocated. The total number of instructions emitted for BPF trampoline JIT code depends on where the final image is located. So, the size arrived at with the dummy pass in arch_bpf_trampoline_size() can vary from the actual size needed in arch_prepare_bpf_trampoline(). When the instructions accounted in arch_bpf_trampoline_size() is less than the number of instructions emitted during the actual JIT compile of the trampoline, the below warning is produced: WARNING: CPU: 8 PID: 204190 at arch/powerpc/net/bpf_jit_comp.c:981 __arch_prepare_bpf_trampoline.isra.0+0xd2c/0xdcc which is: /* Make sure the trampoline generation logic doesn't overflow */ if (image && WARN_ON_ONCE(&image[ctx->idx] > (u32 *)rw_image_end - BPF_INSN_SAFETY)) { So, during the dummy pass, instead of providing some arbitrary image location, account for maximum possible instructions if and when there is a dependency with image location for JIT'ing.
How severe is CVE-2025-38339?
CVE-2025-38339 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-38339 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-38339?
CVE-2025-38339 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-38339?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-38339 have an EU (EUVD) identifier?
Yes. CVE-2025-38339 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-20907.
When was CVE-2025-38339 published?
CVE-2025-38339 was published on 2025-07-10 and last updated on 2026-06-17.

References

Affected products (1)

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