CVE-2025-40272

Description

In the Linux kernel, the following vulnerability has been resolved: mm/secretmem: fix use-after-free race in fault handler When a page fault occurs in a secret memory file created with `memfd_secret(2)`, the kernel will allocate a new folio for it, mark the underlying page as not-present in the direct map, and add it to the file mapping. If two tasks cause a fault in the same page concurrently, both could end up allocating a folio and removing the page from the direct map, but only one would succeed in adding the folio to the file mapping. The task that failed undoes the effects of its attempt by (a) freeing the folio again and (b) putting the page back into the direct map. However, by doing these two operations in this order, the page becomes available to the allocator again before it is placed back in the direct mapping. If another task attempts to allocate the page between (a) and (b), and the kernel tries to access it via the direct map, it would result in a supervisor not-present page fault. Fix the ordering to restore the direct map before the folio is freed.

Gravité et risque d'exploitation

CVE-2025-40272 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 3.2 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.1.*, <=6.12.*, <6f86d0534fddfbd08687fa0f01479d4226bc3c3d, 0, <5.14, 6.18, <1e4643d6628edf9c0047b1f8f5bc574665025acb, <=6.6.*, 5.14, <42d486d35a4143cc37fc72ee66edc99d942dd367, <52f2d5cf33de9a8f5e72bbb0ed38282ae0bc4649, 6.6.117, 5.15.197, 6.1.159, 6.12.59, <=*, <bb1c19636aedae39360e6fdbcaef4f2bcff25785, 1507f51255c9ff07d75909a84e7c0d7f3c4b2f49, <=5.15.*, <=6.17.*, <4444767e625da46009fc94a453fd1967b80ba047, 6.17.9) 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/bb1c19636aedae39360e6fdbcaef4f2bcff25785
• https://git.kernel.org/stable/c/1e4643d6628edf9c0047b1f8f5bc574665025acb
• https://git.kernel.org/stable/c/42d486d35a4143cc37fc72ee66edc99d942dd367
• https://git.kernel.org/stable/c/52f2d5cf33de9a8f5e72bbb0ed38282ae0bc4649
• https://git.kernel.org/stable/c/4444767e625da46009fc94a453fd1967b80ba047
• https://git.kernel.org/stable/c/6f86d0534fddfbd08687fa0f01479d4226bc3c3d