net/sched: cls_fw: fix NULL pointer dereference on shared blocks (Linux Linux)

CVE-2026-31421
MEDIUM 5.5

En bref

Source
NVD
EPSS
EPSS 0.12 % · centile 2 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
Linux
Statut NVD
Modified

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_fw: fix NULL pointer dereference on shared blocks The old-method path in fw_classify() calls tcf_block_q() and dereferences q->handle. Shared blocks leave block->q NULL, causing a NULL deref when an empty cls_fw filter is attached to a shared block and a packet with a nonzero major skb mark is classified. Reject the configuration in fw_change() when the old method (no TCA_OPTIONS) is used on a shared block, since fw_classify()'s old-method path needs block->q which is NULL for shared blocks. The fixed null-ptr-deref calling stack: KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:fw_classify (net/sched/cls_fw.c:81) Call Trace: tcf_classify (./include/net/tc_wrapper.h:197 net/sched/cls_api.c:1764 net/sched/cls_api.c:1860) tc_run (net/core/dev.c:4401) __dev_queue_xmit (net/core/dev.c:4535 net/core/dev.c:4790)

Faiblesses (CWE)

  • CWE-476 — Déréférencement de pointeur nul

Références

Scores

VersionScoreVecteurÉvalué par
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

Références européennes

Avis du CERT-FR

Configurations affectées (CPE NVD)

Produits affectés

ProduitVersions
Linux · Linuxaffected 1abf272022cf1d18469405f47b4ec49c6a3125db < d6d5bd62a09650856e1e2010eb09853eba0d64e1 ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < febf64ca79a2d6540ab6e5e197fa0f4f7e84473e ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < 3d41f9a314afa94b1c7c7c75405920123220e8cd ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < 18328eff2f97d1a6adcdb6d4a0f42f2f83a31e28 ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < 5cf41031922c154aa5ccda8bcdb0f5e6226582ec ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < 3cb055df9e8625ce699a259d8178d67b37f2b160
Linux · Linuxaffected 4.15 ; unaffected 0 < 4.15 ; unaffected 5.10.253 ≤ 5.10.* ; unaffected 5.15.203 ≤ 5.15.* ; unaffected 6.1.168 ≤ 6.1.* ; unaffected 6.6.134 ≤ 6.6.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD