CVE-2025-37893: In the Linux kernel, the following vulnerability has been resolved: LoongArch: BPF: Fix off-by-one error in build_prologue() Vincent reported that r...

Description

In the Linux kernel, the following vulnerability has been resolved: LoongArch: BPF: Fix off-by-one error in build_prologue() Vincent reported that running BPF progs with tailcalls on LoongArch causes kernel hard lockup. Debugging the issues shows that the JITed image missing a jirl instruction at the end of the epilogue. There are two passes in JIT compiling, the first pass set the flags and the second pass generates JIT code based on those flags. With BPF progs mixing bpf2bpf and tailcalls, build_prologue() generates N insns in the first pass and then generates N+1 insns in the second pass. This makes epilogue_offset off by one and we will jump to some unexpected insn and cause lockup. Fix this by inserting a nop insn.

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

0.22%

12.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	>= 6.1, < 6.1.134
Linux	Linux Kernel	>= 6.2, < 6.6.87
Linux	Linux Kernel	>= 6.7, < 6.12.23
Linux	Linux Kernel	>= 6.13, < 6.13.11
Linux	Linux Kernel	>= 6.14, < 6.14.2

References

Timeline

Published: Apr 18, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-37893?

In the Linux kernel, the following vulnerability has been resolved: LoongArch: BPF: Fix off-by-one error in build_prologue() Vincent reported that running BPF progs with tailcalls on LoongArch causes kernel hard lockup. Debugging the issues shows that the JITed image missing a jirl instruction at the end of the epilogue. There are two passes in JIT compiling, the first pass set the flags and the second pass generates JIT code based on those flags. With BPF progs mixing bpf2bpf and tailcalls, build_prologue() generates N insns in the first pass and then generates N+1 insns in the second pass. This makes epilogue_offset off by one and we will jump to some unexpected insn and cause lockup. Fix this by inserting a nop insn.

How severe is CVE-2025-37893?

CVE-2025-37893 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.

How do I fix CVE-2025-37893?

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.