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

CVE-2026-31422
MEDIUM 5.5

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_flow: fix NULL pointer dereference on shared blocks flow_change() calls tcf_block_q() and dereferences q->handle to derive a default baseclass. Shared blocks leave block->q NULL, causing a NULL deref when a flow filter without a fully qualified baseclass is created on a shared block. Check tcf_block_shared() before accessing block->q and return -EINVAL for shared blocks. This avoids the null-deref shown below: ======================================================================= KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:flow_change (net/sched/cls_flow.c:508) Call Trace: tc_new_tfilter (net/sched/cls_api.c:2432) rtnetlink_rcv_msg (net/core/rtnetlink.c:6980) [...] =======================================================================

Weaknesses (CWE)

  • CWE-476 — NULL Pointer Dereference

References

Scores

VersionScoreVectorScored by
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)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 1abf272022cf1d18469405f47b4ec49c6a3125db < 57f94ac7e953eece5ed4819605a18f3cdfc63dcc ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < 942813276edeb1741fa5b0a73471beb4e495fa08 ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < cc707a4fd4c3b6ab2722e06bc359aa010e13d408 ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < 4a09f72007201c9f667dc47f64517ec23eea65e5 ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < 9bf5fc36a43f7b8b5507c96e74fb81f1e8b4957e ; affected 1abf272022cf1d18469405f47b4ec49c6a3125db < a208c3e1232997e9317887294c20008dfcb75449
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