CVE-2026-80710

Description

In the Linux kernel, the following vulnerability has been resolved: s390/dasd: Fix undersized format-check buffer fmt_buffer_size in dasd_eckd_check_device_format() is declared as int, even though one of the multiplicands, sizeof(struct eckd_count), is a size_t. The expression trkcount * rpt_max * sizeof(struct eckd_count) is therefore correctly evaluated at 64-bit width, but the result is silently truncated when it is stored back into the 32-bit fmt_buffer_size variable. For a sufficiently large track range (start_unit/stop_unit are caller-controlled) this truncation yields a buffer size far smaller than the number of tracks actually requested. kzalloc() then succeeds with an undersized allocation, while the subsequent channel program build still operates on the untruncated track count and writes past the end of that buffer. Compute the buffer size with check_mul_overflow() and keep it in a size_t, so that a value that no longer fits results in -EINVAL instead of a silently truncated allocation size.

Gravité et risque d'exploitation

CVE-2026-80710 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 0.18 %, ce qui la place devant 6.6 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.12.*, 8fd575200db5b53f6ea6818dd017f1b43190db12, <aca18289c86f22d3fc2f3f6ff615286e7b1702f6, 0, <9f88dda2f22927d22498801a92cab6a9424eaf86, <=7.1.*, <7f40b346462f563a0d6e841a77b5163d2a882a04, <e16e0fc54120cee3c6f0362de95aab6792865857, 6.12.103, <=6.6.*, 4.7, <=6.18.*, <=*, 7.1.8, <4.7, <87f3389cd3920714c53e704778f7ca7f1cf0c39c, 6.18.44, 6.6.151, 7.2) 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/aca18289c86f22d3fc2f3f6ff615286e7b1702f6
• https://git.kernel.org/stable/c/9f88dda2f22927d22498801a92cab6a9424eaf86
• https://git.kernel.org/stable/c/e16e0fc54120cee3c6f0362de95aab6792865857
• https://git.kernel.org/stable/c/87f3389cd3920714c53e704778f7ca7f1cf0c39c
• https://git.kernel.org/stable/c/7f40b346462f563a0d6e841a77b5163d2a882a04