CVE-2026-64449

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.8 · Élevée
EPSS 0.1%
Linux•Linux•Versions : <e99f2df433c63c86c93de1e5f08f16e404388756, <=6.1.*, <2.6.32, <=6.12.*, f00a86d98a1ec3e99d352cda926fab767ba43b1f, 6.18.39, 0, <8eff7cd4817e14dbe3b9952cce55ef52d1d38940, <=7.1.*, 7.1.4, <1b495fa0d4927c88d88bf346bf311f2e26e860ed, 6.1.178, <65358d89dc9f1c25d9364b2b3ef0f3b47717f9ed, <=6.6.*, <=6.18.*, 2.6.32, <adc8b9c30d716c362646edb45662aa1c641a154a, 6.6.145, <=*, <9f32f38265014fac7f5dc9490fb01a638ce6e121, 6.12.96, 7.2

Description

In the Linux kernel, the following vulnerability has been resolved: staging: vme_user: bound slave read/write to the kern_buf size The SLAVE-path helpers buffer_to_user() and buffer_from_user() copy 'count' bytes into/out of the fixed-size kern_buf (size_buf == PCI_BUF_SIZE == 0x20000, 128 KiB) using *ppos as the offset, without bounding *ppos + count against size_buf. vme_user_write()/vme_user_read() only clamp count to the VME window size (image_size = vme_get_size(resource)), which VME_SET_SLAVE sets from the user-supplied slave.size -- validated against the VME address space (up to VME_A32_MAX = 4 GiB), not against PCI_BUF_SIZE. When the window exceeds 128 KiB, a write()/read() copies past the kern_buf allocation. Clamp count against size_buf in both helpers, with an early return when *ppos is already at/after the buffer end. *ppos is >= 0 here (the caller rejects negative offsets), so size_buf - *ppos cannot wrap. This mirrors the existing clamp in the MASTER-path helpers resource_to_user() / resource_from_user(), and matches the read()/write() convention of a short transfer at end-of-buffer. Found by static analysis (CodeQL taint tracking + CBMC bounded model checking) and confirmed dynamically under KASAN with the vme_fake bridge: BUG: KASAN: slab-out-of-bounds in _copy_from_user+0x2d/0x80 Write of size 262144 at addr ffff888004100000 by task trigger/68 _copy_from_user+0x2d/0x80 vme_user_write+0x13e/0x240 [vme_user] vfs_write+0x1b8/0x7a0 ksys_write+0xb8/0x150

Gravité et risque d'exploitation

CVE-2026-64449 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 0.14 %, ce qui la place devant 2.9 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <e99f2df433c63c86c93de1e5f08f16e404388756, <=6.1.*, <2.6.32, <=6.12.*, f00a86d98a1ec3e99d352cda926fab767ba43b1f, 6.18.39, 0, <8eff7cd4817e14dbe3b9952cce55ef52d1d38940, <=7.1.*, 7.1.4, <1b495fa0d4927c88d88bf346bf311f2e26e860ed, 6.1.178, <65358d89dc9f1c25d9364b2b3ef0f3b47717f9ed, <=6.6.*, <=6.18.*, 2.6.32, <adc8b9c30d716c362646edb45662aa1c641a154a, 6.6.145, <=*, <9f32f38265014fac7f5dc9490fb01a638ce6e121, 6.12.96, 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