CVE-2025-21965
published 2025-04-01CVE-2025-21965: 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…
PriorityP418medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.19%
8.5th percentile
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
15 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | linux | < linux 6.12.20-1 (forky) | linux 6.12.20-1 (forky) |
| linux | linux | — | — |
| linux | linux | >= f0e1a0643a59bf1f922fa209cec86a170b784f3f < 752b56bb76e2471197d25d6948d85753043b10da | 752b56bb76e2471197d25d6948d85753043b10da |
| linux | linux | >= f0e1a0643a59bf1f922fa209cec86a170b784f3f < 515680e76c536dd4aa8e2b5d674b0d441baddf5b | 515680e76c536dd4aa8e2b5d674b0d441baddf5b |
| linux | linux | >= f0e1a0643a59bf1f922fa209cec86a170b784f3f < 9360dfe4cbd62ff1eb8217b815964931523b75b3 | 9360dfe4cbd62ff1eb8217b815964931523b75b3 |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 0 < 6.12.20-1 | 6.12.20-1 |
| linux | linux_kernel | >= 0 < 6.12.20-1 | 6.12.20-1 |
| linux | linux_kernel | >= 6.12 < 6.12.20 | 6.12.20 |
| linux | linux_kernel | >= 6.13 < 6.13.8 | 6.13.8 |
CVSS provenance
nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5LOW
vendor_redhat5.5MEDIUM
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
Red Hat
kernel: sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl()
vendor_redhat·2025-04-01·CVSS 5.5
CVE-2025-21965 [MEDIUM] kernel: sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl()
kernel: sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl()
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.
Package: kernel (Red Hat Enterprise Linux 10) - Not affected
Package: kernel (Red Hat Enterprise Linux 6) - Not affected
Package: kernel (Red Hat Enterprise Linux 7) - Not affected
Package: kernel-rt (Red Hat Enterprise Linux 7) - Not affected
Package: kernel (Red Hat Enterprise Linux 8) - Not affected
Package: kernel-rt (Red Hat Enterpri
Debian
CVE-2025-21965: linux - In the Linux kernel, the following vulnerability has been resolved: sched_ext: ...
vendor_debian·2025·CVSS 5.5
CVE-2025-21965 [MEDIUM] CVE-2025-21965: linux - In the Linux kernel, the following vulnerability has been resolved: sched_ext: ...
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.
Scope: local
bookworm: resolved
bullseye: resolved
forky: resolved (fixed in 6.12.20-1)
sid: resolved (fixed in 6.12.20-1)
trixie: resolved (fixed in 6.12.20-1)
VulDB
Linux Kernel up to 6.12.19/6.13.7 scx_bpf_select_cpu_dfl denial of service (WID-SEC-2025-0683)
vuldb·2026-07-31·CVSS 5.5
CVE-2025-21965 [MEDIUM] Linux Kernel up to 6.12.19/6.13.7 scx_bpf_select_cpu_dfl denial of service (WID-SEC-2025-0683)
A vulnerability was found in Linux Kernel up to 6.12.19/6.13.7. It has been rated as critical. The affected element is the function scx_bpf_select_cpu_dfl. Performing a manipulation results in denial of service.
This vulnerability is known as CVE-2025-21965. Access to the local network is required for this attack. No exploit is available.
Upgrading the affected component is advised.
OSV
CVE-2025-21965: 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 provid
osv·2025-04-01·CVSS 5.5
CVE-2025-21965 [MEDIUM] CVE-2025-21965: 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 provid
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.
GHSA
GHSA-9gr8-3pvc-4w93: 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 prov
ghsa_unreviewed·2025-04-01
CVE-2025-21965 [MEDIUM] CWE-476 GHSA-9gr8-3pvc-4w93: 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 prov
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.
No detection rules found.
No public exploits indexed.
2025-04-01
Published