CVE-2026-89559

Description

In the Linux kernel, the following vulnerability has been resolved: libnvdimm/labels: Prevent integer overflow in __nd_label_validate() The on-media namespace index field nslot is a u32 read from the DIMM label storage area. __nd_label_validate() bounds it against the config area size, but sizeof_namespace_label() returns unsigned, so the product nslot * label_size is evaluated in 32-bit and wraps modulo 2^32 before the comparison. A crafted nslot passes the bound and is then used as the loop trip count in nd_label_data_init(), whose memset() walks off the end of the config_size buffer: an out-of-bounds write. The field is not trusted -- it comes from the medium, or from userspace via ND_CMD_SET_CONFIG_DATA. Evaluate the product in 64-bit so the bound check is exact; conforming labels are unaffected. The check was safe when introduced by commit 4a826c83db4e ("libnvdimm: namespace indices: read and validate"): it multiplied by sizeof(struct nd_namespace_label), a size_t, so on a 64-bit build the product did not wrap. Commit 564e871aa66f ("libnvdimm, label: add v1.2 nvdimm label definitions") narrowed it to 32 bits when the label size became a runtime value read via sizeof_namespace_label().

Gravité et risque d'exploitation

CVE-2026-89559 obtient un score CVSS de 7.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.17 %, ce qui la place devant 5.8 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.1.*, <69a734359639fca16a0dd73ab17a34943e76c68b, <e057efcc9c71d90099d9ee00bed0748d0e9fd586, <=6.12.*, 5.15.221, 5.10.270, 0, <09e649117c54b7e1c004f22eaa19efbadd9ac856, 7.2.4, 564e871aa66f548a947b23808d3140f326381f0c, 6.1.188, <=5.10.*, <=6.6.*, <93967bfb17dab66642c57e609c99e1a91fe11278, 4.13, 6.6.157, <b4975f2ff6c82adc24ae547f029f82530ba43cfe, <=6.18.*, 7.3, <1c391696d2791f82ae462e11da9a0d96f90b240c, <=7.2.*, <4.13, <=*, <=5.15.*, 6.18.50, <037770686126155eafc44501312989e2837b9659, 6.12.109, <6030597ec683d1e5b46445f888bb5c7776b5a0c4) est présent sur votre parc.
• Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
• À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
• Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

• https://git.kernel.org/stable/c/b4975f2ff6c82adc24ae547f029f82530ba43cfe
• https://git.kernel.org/stable/c/6030597ec683d1e5b46445f888bb5c7776b5a0c4
• https://git.kernel.org/stable/c/1c391696d2791f82ae462e11da9a0d96f90b240c
• https://git.kernel.org/stable/c/93967bfb17dab66642c57e609c99e1a91fe11278
• https://git.kernel.org/stable/c/e057efcc9c71d90099d9ee00bed0748d0e9fd586
• https://git.kernel.org/stable/c/09e649117c54b7e1c004f22eaa19efbadd9ac856
• https://git.kernel.org/stable/c/69a734359639fca16a0dd73ab17a34943e76c68b
• https://git.kernel.org/stable/c/037770686126155eafc44501312989e2837b9659