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NVD / CVE Program· CNA Linux

CVE-2025-38255: lib/group_cpus: fix NULL pointer dereference from group_cpus_evenly()

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.16% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 29d39e0d5f16c060e32542b2cf351c09fd22b250, 64a99eff8dcf1f951a544e6058341b2b19a8fdbd, 911ef2e8a7de5b2bae8ff11fb0bd01f699e6db65.

Low priority for now. Upgrade to Linux Linux 29d39e0d5f16c060e32542b2cf351c09fd22b250, 64a99eff8dcf1f951a544e6058341b2b19a8fdbd, 911ef2e8a7de5b2bae8ff11fb0bd01f699e6db65 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: lib/group_cpus: fix NULL pointer dereference from group_cpus_evenly() While testing null_blk with configfs, echo 0 > poll_queues will trigger following panic: BUG: kernel NULL pointer dereference, address: 0000000000000010 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 27 UID: 0 PID: 920 Comm: bash Not tainted 6.15.0-02023-gadbdb95c8696-dirty #1238 PREEMPT(undef) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 RIP: 0010:__bitmap_or+0x48/0x70 Call Trace: <TASK> __group_cpus_evenly+0x822/0x8c0 group_cpus_evenly+0x2d9/0x490 blk_mq_map_queues+0x1e/0x110 null_map_queues+0xc9/0x170 [null_blk] blk_mq_update_queue_map+0xdb/0x160 blk_mq_update_nr_hw_queues+0x22b/0x560 nullb_update_nr_hw_queues+0x71/0xf0 [null_blk] nullb_device_poll_queues_store+0xa4/0x130 [null_blk] configfs_write_iter+0x109/0x1d0 vfs_write+0x26e/0x6f0 ksys_write+0x79/0x180 __x64_sys_write+0x1d/0x30 x64_sys_call+0x45c4/0x45f0 do_syscall_64+0xa5/0x240 entry_SYSCALL_64_after_hwframe+0x76/0x7e Root cause is that numgrps is set to 0, and ZERO_SIZE_PTR is returned from kcalloc(), and later ZERO_SIZE_PTR will be deferenced. Fix the problem by checking numgrps first in group_cpus_evenly(), and return NULL directly if numgrps is zero. [yukuai3@huawei.com: also fix the non-SMP version]

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Jul 9, 2025
Updated
Jun 17, 2026
EPSS
0.1% · 5th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel6.3 and later · before 6.6.96
  • linux linux kernel6.7 and later · before 6.12.36
  • linux linux kernel6.13 and later · before 6.15.5
  • linux linux kernel6.16

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.3affected
    • 6a6dcae8f486c3f3298d0767d34505121c7b0b81 and later · before 64a99eff8dcf1f951a544e6058341b2b19a8fdbdaffected · git
    • 6a6dcae8f486c3f3298d0767d34505121c7b0b81 and later · before 29d39e0d5f16c060e32542b2cf351c09fd22b250affected · git
    • 6a6dcae8f486c3f3298d0767d34505121c7b0b81 and later · before 911ef2e8a7de5b2bae8ff11fb0bd01f699e6db65affected · git
    • 6a6dcae8f486c3f3298d0767d34505121c7b0b81 and later · before df831e97739405ecbaddb85516bc7d4d1c933d6baffected · git
    • before 6.3not affected · semver
    • 6.6.96 and later · up to and including 6.6.*not affected · semver
    • 6.12.36 and later · up to and including 6.12.*not affected · semver
    • 6.15.5 and later · up to and including 6.15.*not affected · semver
    • 6.16 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:13linuxbefore 6.12.37-16.12.37-1
SUSE:Linux Enterprise Live Patching 15 SP7kernel-livepatch-SLE15-SP7_Update_5before 1-150700.15.3.11-150700.15.3.1
SUSE:Linux Enterprise Live Patching 15 SP7kernel-livepatch-SLE15-SP7-RT_Update_5before 1-150700.1.3.11-150700.1.3.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-64kbbefore 6.4.0-150700.53.19.16.4.0-150700.53.19.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-defaultbefore 6.4.0-150700.53.19.16.4.0-150700.53.19.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-default-basebefore 6.4.0-150700.53.19.1.150700.17.13.16.4.0-150700.53.19.1.150700.17.13.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-sourcebefore 6.4.0-150700.53.19.16.4.0-150700.53.19.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-zfcpdumpbefore 6.4.0-150700.53.19.16.4.0-150700.53.19.1
SUSE:Linux Enterprise Module for Development Tools 15 SP7kernel-docsbefore 6.4.0-150700.53.19.16.4.0-150700.53.19.1
SUSE:Linux Enterprise Module for Development Tools 15 SP7kernel-obs-buildbefore 6.4.0-150700.53.19.16.4.0-150700.53.19.1
SUSE:Linux Enterprise Module for Development Tools 15 SP7kernel-symsbefore 6.4.0-150700.53.19.16.4.0-150700.53.19.1
SUSE:Real Time Module 15 SP7kernel-rtbefore 6.4.0-150700.7.19.16.4.0-150700.7.19.1
SUSE:Real Time Module 15 SP7kernel-source-rtbefore 6.4.0-150700.7.19.16.4.0-150700.7.19.1
SUSE:Real Time Module 15 SP7kernel-syms-rtbefore 6.4.0-150700.7.19.16.4.0-150700.7.19.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2025-38252Jul 9, 2025 · cxl/ras: Fix CPER handler device confusion
    22Monitor
  • ← EarlierCVE-2025-38254Jul 9, 2025 · drm/amd/display: Add sanity checks for drm_edid_raw()
    22Monitor
  • Later →CVE-2025-38256Jul 9, 2025 · io_uring/rsrc: fix folio unpinning
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux29d39e0d5f16c060e32542b2cf351c09fd22b250Vendor (CNA)
Linux Linux64a99eff8dcf1f951a544e6058341b2b19a8fdbdVendor (CNA)
Linux Linux911ef2e8a7de5b2bae8ff11fb0bd01f699e6db65Vendor (CNA)
Linux Linuxdf831e97739405ecbaddb85516bc7d4d1c933d6bVendor (CNA)
debian:linux6.12.37-1 · Debian:13Package registry (OSV)
suse:kernel-64kb6.4.0-150700.53.19.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:kernel-default6.4.0-150700.53.19.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:kernel-default-base6.4.0-150700.53.19.1.150700.17.13.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:kernel-docs6.4.0-150700.53.19.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP7Package registry (OSV)
suse:kernel-livepatch-SLE15-SP7_Update_51-150700.15.3.1 · SUSE:Linux Enterprise Live Patching 15 SP7Package registry (OSV)
suse:kernel-livepatch-SLE15-SP7-RT_Update_51-150700.1.3.1 · SUSE:Linux Enterprise Live Patching 15 SP7Package registry (OSV)
suse:kernel-obs-build6.4.0-150700.53.19.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP7Package registry (OSV)
suse:kernel-rt6.4.0-150700.7.19.1 · SUSE:Real Time Module 15 SP7Package registry (OSV)
suse:kernel-source6.4.0-150700.53.19.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:kernel-source-rt6.4.0-150700.7.19.1 · SUSE:Real Time Module 15 SP7Package registry (OSV)
suse:kernel-syms6.4.0-150700.53.19.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP7Package registry (OSV)
suse:kernel-zfcpdump6.4.0-150700.53.19.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records