net/sched: cls_fw: fix NULL pointer dereference on shared blocks (Linux Linux)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.12 % · percentile 2 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- 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)
Weaknesses (CWE)
- CWE-476 — NULL Pointer Dereference
References
- https://git.kernel.org/stable/c/d6d5bd62a09650856e1e2010eb09853eba0d64e1
- https://git.kernel.org/stable/c/febf64ca79a2d6540ab6e5e197fa0f4f7e84473e
- https://git.kernel.org/stable/c/3d41f9a314afa94b1c7c7c75405920123220e8cd
- https://git.kernel.org/stable/c/18328eff2f97d1a6adcdb6d4a0f42f2f83a31e28
- https://git.kernel.org/stable/c/5cf41031922c154aa5ccda8bcdb0f5e6226582ec
- https://git.kernel.org/stable/c/3cb055df9e8625ce699a259d8178d67b37f2b160
- https://git.kernel.org/stable/c/96426c348def662b06bfdc65be3002905604927a
- https://git.kernel.org/stable/c/faeea8bbf6e958bf3c00cb08263109661975987c
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2026-21945
- GCVE · GCVE-0-2026-31421
CERT-FR advisories
- CERTFR-2026-AVI-1298 — Multiples vulnérabilités dans les produits Siemens · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1229 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1093 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1066 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0985 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0954 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0926 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0880 — Multiples vulnérabilités dans les produits Siemens · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0782 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0697 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0696 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0548 — Multiples vulnérabilités dans le noyau Linux de Debian · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0547 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0463 — Multiples vulnérabilités dans les produits Microsoft · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 4.15 < 5.10.253cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.11 < 5.15.203cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.16 < 6.1.168cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.2 < 6.6.134cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.7 < 6.12.81cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13 < 6.18.22cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.19 < 6.19.12cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected 1abf272022cf1d18469405f47b4ec49c6a3125db < d6d5bd62a09650856e1e2010eb09853eba0d64e1 ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < febf64ca79a2d6540ab6e5e197fa0f4f7e84473e ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < 3d41f9a314afa94b1c7c7c75405920123220e8cd ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < 18328eff2f97d1a6adcdb6d4a0f42f2f83a31e28 ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < 5cf41031922c154aa5ccda8bcdb0f5e6226582ec ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < 3cb055df9e8625ce699a259d8178d67b37f2b160 |
| Linux · Linux | affected 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
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |