In the Linux kernel, the following vulnerability has been resolved:

bpf, arm64: Fix fp initialization for exception boundary

In the ARM64 BPF JIT when prog->aux->exception_boundary is set for a BPF
program, find_used_callee_regs() is not called because for a program
acting as exception boundary, all callee saved registers are saved.
find_used_callee_regs() sets `ctx->fp_used = true;` when it sees FP
being used in any of the instructions.

For programs acting as exception boundary, ctx->fp_used remains false
even if frame pointer is used by the program and therefore, FP is not
set-up for such programs in the prologue. This can cause the kernel to
crash due to a pagefault.

Fix it by setting ctx->fp_used = true for exception boundary programs as
fp is always saved in such programs.
Advisories
Source ID Title
EUVD EUVD EUVD-2025-27915 In the Linux kernel, the following vulnerability has been resolved: bpf, arm64: Fix fp initialization for exception boundary In the ARM64 BPF JIT when prog->aux->exception_boundary is set for a BPF program, find_used_callee_regs() is not called because for a program acting as exception boundary, all callee saved registers are saved. find_used_callee_regs() sets `ctx->fp_used = true;` when it sees FP being used in any of the instructions. For programs acting as exception boundary, ctx->fp_used remains false even if frame pointer is used by the program and therefore, FP is not set-up for such programs in the prologue. This can cause the kernel to crash due to a pagefault. Fix it by setting ctx->fp_used = true for exception boundary programs as fp is always saved in such programs.
Ubuntu USN Ubuntu USN USN-7879-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7879-2 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7880-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7879-3 Linux kernel vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 26 Nov 2025 18:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-476
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Thu, 21 Aug 2025 12:45:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Wed, 20 Aug 2025 00:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low


Tue, 19 Aug 2025 17:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: bpf, arm64: Fix fp initialization for exception boundary In the ARM64 BPF JIT when prog->aux->exception_boundary is set for a BPF program, find_used_callee_regs() is not called because for a program acting as exception boundary, all callee saved registers are saved. find_used_callee_regs() sets `ctx->fp_used = true;` when it sees FP being used in any of the instructions. For programs acting as exception boundary, ctx->fp_used remains false even if frame pointer is used by the program and therefore, FP is not set-up for such programs in the prologue. This can cause the kernel to crash due to a pagefault. Fix it by setting ctx->fp_used = true for exception boundary programs as fp is always saved in such programs.
Title bpf, arm64: Fix fp initialization for exception boundary
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-09-29T05:54:18.300Z

Reserved: 2025-04-16T04:51:24.026Z

Link: CVE-2025-38586

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2025-08-19T17:15:36.113

Modified: 2025-11-26T17:58:10.127

Link: CVE-2025-38586

cve-icon Redhat

Severity : Low

Publid Date: 2025-08-19T00:00:00Z

Links: CVE-2025-38586 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-08-21T12:31:36Z