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NVD / CVE Program· CNA Linux

CVE-2025-38684: net/sched: ets: use old 'nbands' while purging unused classes

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: 0.18% (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 5.5, 5b3b346bc4c2aa2c428735438a11989d251f32f1, 84a24fb446ee07b22b64aae6f0e3f4a38266310a.

Low priority for now. Upgrade to Linux Linux 5.5, 5b3b346bc4c2aa2c428735438a11989d251f32f1, 84a24fb446ee07b22b64aae6f0e3f4a38266310a 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: net/sched: ets: use old 'nbands' while purging unused classes Shuang reported sch_ets test-case [1] crashing in ets_class_qlen_notify() after recent changes from Lion [2]. The problem is: in ets_qdisc_change() we purge unused DWRR queues; the value of 'q->nbands' is the new one, and the cleanup should be done with the old one. The problem is here since my first attempts to fix ets_qdisc_change(), but it surfaced again after the recent qdisc len accounting fixes. Fix it purging idle DWRR queues before assigning a new value of 'q->nbands', so that all purge operations find a consistent configuration: - old 'q->nbands' because it's needed by ets_class_find() - old 'q->nstrict' because it's needed by ets_class_is_strict() BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 62 UID: 0 PID: 39457 Comm: tc Kdump: loaded Not tainted 6.12.0-116.el10.x86_64 #1 PREEMPT(voluntary) Hardware name: Dell Inc. PowerEdge R640/06DKY5, BIOS 2.12.2 07/09/2021 RIP: 0010:__list_del_entry_valid_or_report+0x4/0x80 Code: ff 4c 39 c7 0f 84 39 19 8e ff b8 01 00 00 00 c3 cc cc cc cc 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <48> 8b 17 48 8b 4f 08 48 85 d2 0f 84 56 19 8e ff 48 85 c9 0f 84 ab RSP: 0018:ffffba186009f400 EFLAGS: 00010202 RAX: 00000000000000d6 RBX: 0000000000000000 RCX: 0000000000000004 RDX: ffff9f0fa29b69c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffffc12c2400 R08: 0000000000000008 R09: 0000000000000004 R10: ffffffffffffffff R11: 0000000000000004 R12: 0000000000000000 R13: ffff9f0f8cfe0000 R14: 0000000000100005 R15: 0000000000000000 FS: 00007f2154f37480(0000) GS:ffff9f269c1c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001530be001 CR4: 00000000007726f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ets_class_qlen_notify+0x65/0x90 [sch_ets] qdisc_tree_reduce_backlog+0x74/0x110 ets_qdisc_change+0x630/0xa40 [sch_ets] __tc_modify_qdisc.constprop.0+0x216/0x7f0 tc_modify_qdisc+0x7c/0x120 rtnetlink_rcv_msg+0x145/0x3f0 netlink_rcv_skb+0x53/0x100 netlink_unicast+0x245/0x390 netlink_sendmsg+0x21b/0x470 ____sys_sendmsg+0x39d/0x3d0 ___sys_sendmsg+0x9a/0xe0 __sys_sendmsg+0x7a/0xd0 do_syscall_64+0x7d/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f2155114084 Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d 25 f0 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89 RSP: 002b:00007fff1fd7a988 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000560ec063e5e0 RCX: 00007f2155114084 RDX: 0000000000000000 RSI: 00007fff1fd7a9f0 RDI: 0000000000000003 RBP: 00007fff1fd7aa60 R08: 0000000000000010 R09: 000000000000003f R10: 0000560ee9b3a010 R11: 0000000000000202 R12: 00007fff1fd7aae0 R13: 000000006891ccde R14: 0000560ec063e5e0 R15: 00007fff1fd7aad0 </TASK> [1] https://lore.kernel.org/netdev/e08c7f4a6882f260011909a868311c6e9b54f3e4.1639153474.git.dcaratti@redhat.com/ [2] https://lore.kernel.org/netdev/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com/

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Sep 4, 2025
Updated
Oct 19, 2026
EPSS
0.1% · 7th 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%

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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
debiandebian linux

Affected versions

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

  • debian debian linux11.0
  • linux linux kernel5.6 and later · before 5.10.241
  • linux linux kernel5.11 and later · before 5.15.190
  • linux linux kernel5.16 and later · before 6.1.149
  • linux linux kernel6.2 and later · before 6.6.103
  • linux linux kernel5.4.296 and later · before 5.5
  • linux linux kernel6.13 and later · before 6.15.11
  • linux linux kernel6.16 and later · before 6.16.2
  • linux linux kernel6.7 and later · before 6.12.43
  • linux linux kernel6.17

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

    • 3b290923ad2b23596208c1e29520badef4356a43, 5.6affected
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before bdfddcde86e8b9245d9c0c2efe2b6fe8dcf6bf41affected · git
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before be9692dafdfb36d9c43afd9d4e1d9d9ba8e7b51baffected · git
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before 97ec167cd2e8a81a2d87331a2ed92daf007542c8affected · git
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before 84a24fb446ee07b22b64aae6f0e3f4a38266310aaffected · git
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before 5b3b346bc4c2aa2c428735438a11989d251f32f1affected · git
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before d69f4a258cd91b3bcef7089eb0401005aae2aed5affected · git
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before 970c1c731c4ede46d05f5b0355724d1e400cfbcaaffected · git
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before 87c6efc5ce9c126ae4a781bc04504b83780e3650affected · git
    • 5.4.296 and later · before 5.5affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:8bpftoolbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-toolsbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-tools-libsbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-tools-libs-develbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-zfcpdumpbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-zfcpdump-corebefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-zfcpdump-develbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-zfcpdump-modulesbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8kernel-zfcpdump-modules-extrabefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10
AlmaLinux:8perfbefore 4.18.0-553.75.1.el8_104.18.0-553.75.1.el8_10

+96

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-2025-38682Sep 4, 2025 · i2c: core: Fix double-free of fwnode in i2c_unregister_device()
    31Monitor
  • ← EarlierCVE-2025-38683Sep 4, 2025 · hv_netvsc: Fix panic during namespace deletion with VF
    22Monitor
  • Later →CVE-2025-38685Sep 4, 2025 · fbdev: Fix vmalloc out-of-bounds write in fast_imageblit
    31Monitor

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 Linux5.5Vendor (CNA)
Linux Linux5b3b346bc4c2aa2c428735438a11989d251f32f1Vendor (CNA)
Linux Linux84a24fb446ee07b22b64aae6f0e3f4a38266310aVendor (CNA)
Linux Linux87c6efc5ce9c126ae4a781bc04504b83780e3650Vendor (CNA)
Linux Linux970c1c731c4ede46d05f5b0355724d1e400cfbcaVendor (CNA)
Linux Linux97ec167cd2e8a81a2d87331a2ed92daf007542c8Vendor (CNA)
Linux Linuxbdfddcde86e8b9245d9c0c2efe2b6fe8dcf6bf41Vendor (CNA)
Linux Linuxbe9692dafdfb36d9c43afd9d4e1d9d9ba8e7b51bVendor (CNA)
Linux Linuxd69f4a258cd91b3bcef7089eb0401005aae2aed5Vendor (CNA)
almalinux:kernel5.14.0-570.39.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-570.39.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-570.39.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-570.39.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-570.39.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-570.39.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-570.39.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-570.39.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-570.39.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-570.39.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel5.14.0-570.39.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel-matched5.14.0-570.39.1.el9_6 · AlmaLinux:9Package registry (OSV)
debian:linux6.1.153-1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:5.14.0-570.39.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel0:5.14.0-570.39.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel-matched0:5.14.0-570.39.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debuginfo0:5.14.0-570.39.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel0:5.14.0-570.39.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel-matched0:5.14.0-570.39.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-debuginfo0:5.14.0-570.39.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel0:5.14.0-570.39.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)

+4

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 (10 more)

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

All records