CVE-2025-21965

sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl()

MEDIUM
5.5
CVSS Score
Published: April 1, 2025 at 03:47 PM UTC
Updated: August 5, 2026 at 12:44 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%

Description

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl() If a BPF scheduler provides an invalid CPU (outside the nr_cpu_ids range) as prev_cpu to scx_bpf_select_cpu_dfl() it can cause a kernel crash. To prevent this, validate prev_cpu in scx_bpf_select_cpu_dfl() and trigger an scx error if an invalid CPU is specified.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.12 ≤ v < 6.12.206.12 ≤ v < 6.13.86.12 ≤ v < 6.146.13 ≤ v < 6.13.86.14 rc16.14 rc26.14 rc36.14 rc46.14 rc56.14 rc6f0e1a0643a59bf1f922fa209cec86a170b784f3f
Vendor states this is fixed in 515680e76c536dd4aa8e2b5d674b0d441baddf5b (fixed)
Vendor states this is fixed in 752b56bb76e2471197d25d6948d85753043b10da (fixed)
Vendor states this is fixed in 9360dfe4cbd62ff1eb8217b815964931523b75b3 (fixed)
Vendor states this is fixed in 6.12 (unaffected)
Vendor states this is fixed in 6.12.20 (unaffected)
Vendor states this is fixed in 6.13.8 (unaffected)
Vendor states this is fixed in 6.14 (unaffected)

References (3)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/515680e76c536dd4aa8e2b5d674b0d441baddf5b
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/752b56bb76e2471197d25d6948d85753043b10da
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/9360dfe4cbd62ff1eb8217b815964931523b75b3

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-476

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