---
id: CVE-2024-50275
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  arm64/sve: Discard stale CPU state when handling SVE traps

  The logic for handling SVE traps manipulates saved FPSIMD/SVE state
  incorrectly, and a race with preemption …
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  arm64/sve: Discard stale CPU state when handling SVE traps

  The logic for handling SVE traps manipulates saved FPSIMD/SVE state
  incorrectly, and a race with preemption …
severity: high
cvss: 7.3
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H'
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.13, < 6.6.61'
  - 'linux_kernel >= 6.7, < 6.11.8'
  - linux_kernel = 6.12
patched:
  - linux_kernel 6.11.8
published: '2024-11-19'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:17:59.383'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2024-50275'
references:
  - url: 'https://git.kernel.org/stable/c/51d11ea0250d6ee461987403bbfd4b2abb5613a7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/51d3d80a6dc314982a9a0aeb0961085922a1aa15'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/751ecf6afd6568adc98f2a6052315552c0483d18'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/de529504b3274d57caf8f66800b714b0d3ee235a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fa9ce027b3ce37a2bb173bf2553b5caa438fd8c9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - cve.org
epss: 0.00242
epssPercentile: 0.15234
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-15T21:40:35.833561Z'
ingestedAt: '2026-10-15T22:48:25.440Z'
---

## Overview

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

arm64/sve: Discard stale CPU state when handling SVE traps

The logic for handling SVE traps manipulates saved FPSIMD/SVE state
incorrectly, and a race with preemption can result in a task having
TIF_SVE set and TIF_FOREIGN_FPSTATE clear even though the live CPU state
is stale (e.g. with SVE traps enabled). This has been observed to result
in warnings from do_sve_acc() where SVE traps are not expected while
TIF_SVE is set:

|         if (test_and_set_thread_flag(TIF_SVE))
|                 WARN_ON(1); /* SVE access shouldn't have trapped */

Warnings of this form have been reported intermittently, e.g.

  https://lore.kernel.org/linux-arm-kernel/CA+G9fYtEGe_DhY2Ms7+L7NKsLYUomGsgqpdBj+QwDLeSg=JhGg@mail.gmail.com/
  https://lore.kernel.org/linux-arm-kernel/000000000000511e9a060ce5a45c@google.com/

The race can occur when the SVE trap handler is preempted before and
after manipulating the saved FPSIMD/SVE state, starting and ending on
the same CPU, e.g.

| void do_sve_acc(unsigned long esr, struct pt_regs *regs)
| {
|         // Trap on CPU 0 with TIF_SVE clear, SVE traps enabled
|         // task->fpsimd_cpu is 0.
|         // per_cpu_ptr(&fpsimd_last_state, 0) is task.
|
|         ...
|
|         // Preempted; migrated from CPU 0 to CPU 1.
|         // TIF_FOREIGN_FPSTATE is set.
|
|         get_cpu_fpsimd_context();
|
|         if (test_and_set_thread_flag(TIF_SVE))
|                 WARN_ON(1); /* SVE access shouldn't have trapped */
|
|         sve_init_regs() {
|                 if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {
|                         ...
|                 } else {
|                         fpsimd_to_sve(current);
|                         current->thread.fp_type = FP_STATE_SVE;
|                 }
|         }
|
|         put_cpu_fpsimd_context();
|
|         // Preempted; migrated from CPU 1 to CPU 0.
|         // task->fpsimd_cpu is still 0
|         // If per_cpu_ptr(&fpsimd_last_state, 0) is still task then:
|         // - Stale HW state is reused (with SVE traps enabled)
|         // - TIF_FOREIGN_FPSTATE is cleared
|         // - A return to userspace skips HW state restore
| }

Fix the case where the state is not live and TIF_FOREIGN_FPSTATE is set
by calling fpsimd_flush_task_state() to detach from the saved CPU
state. This ensures that a subsequent context switch will not reuse the
stale CPU state, and will instead set TIF_FOREIGN_FPSTATE, forcing the
new state to be reloaded from memory prior to a return to userspace.

## Affected

- `linux_kernel >= 5.13, < 6.6.61`
- `linux_kernel >= 6.7, < 6.11.8`
- `linux_kernel = 6.12`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.11.8`