netfilter: ctnetlink: zero expect NAT fields when CTA_EXPECT_NAT absent (Linux Linux)

CVE-2026-43026
MEDIUM 5.5

En bref

Source
NVD
EPSS
EPSS 0.13 % · 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: netfilter: ctnetlink: zero expect NAT fields when CTA_EXPECT_NAT absent ctnetlink_alloc_expect() allocates expectations from a non-zeroing slab cache via nf_ct_expect_alloc(). When CTA_EXPECT_NAT is not present in the netlink message, saved_addr and saved_proto are never initialized. Stale data from a previous slab occupant can then be dumped to userspace by ctnetlink_exp_dump_expect(), which checks these fields to decide whether to emit CTA_EXPECT_NAT. The safe sibling nf_ct_expect_init(), used by the packet path, explicitly zeroes these fields. Zero saved_addr, saved_proto and dir in the else branch, guarded by IS_ENABLED(CONFIG_NF_NAT) since these fields only exist when NAT is enabled. Confirmed by priming the expect slab with NAT-bearing expectations, freeing them, creating a new expectation without CTA_EXPECT_NAT, and observing that the ctnetlink dump emits a spurious CTA_EXPECT_NAT containing stale data from the prior allocation.

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 076a0ca02644657b13e4af363f487ced2942e9cb < a5a89db6981a1ddf2314bf50cb49db5a3146185f ; affected 076a0ca02644657b13e4af363f487ced2942e9cb < 1c2ebdeff8d088a2e47ae25d7b38447249adace2 ; affected 076a0ca02644657b13e4af363f487ced2942e9cb < a64b7bf84b4d5ea54218c5d374ec87fff9000f43 ; affected 076a0ca02644657b13e4af363f487ced2942e9cb < 2898080c054ea4d6ddfaaf21bbedbc229a9a8376 ; affected 076a0ca02644657b13e4af363f487ced2942e9cb < fd002ff2ea030cbfb0188a11b3c60ce7f84485f4 ; affected 076a0ca02644657b13e4af363f487ced2942e9cb < 929f7a9a7aad9404a5867216c3f8738232355b38
Linux · Linuxaffected 3.4 ; unaffected 0 < 3.4 ; 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