CVE-2025-40124
Vulnérabilité élevée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: sparc: fix accurate exception reporting in copy_{from_to}_user for UltraSPARC III Anthony Yznaga tracked down that a BUG_ON in ext4 code with large folios enabled resulted from copy_from_user() returning impossibly large values greater than the size to be copied. This lead to __copy_from_iter() returning impossible values instead of the actual number of bytes it was able to copy. The BUG_ON has been reported in https://lore.kernel.org/r/b14f55642207e63e907965e209f6323a0df6dcee.camel@physik.fu-berlin.de The referenced commit introduced exception handlers on user-space memory references in copy_from_user and copy_to_user. These handlers return from the respective function and calculate the remaining bytes left to copy using the current register contents. The exception handlers expect that %o2 has already been masked during the bulk copy loop, but the masking was performed after that loop. This will fix the return value of copy_from_user and copy_to_user in the faulting case. The behaviour of memcpy stays unchanged.
Gravité et risque d'exploitation
CVE-2025-40124 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 5.5 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <47b49c06eb62504075f0f2e2227aee2e2c2a58b3, <=6.1.*, ee841d0aff649164080e445e84885015958d8ff4, <=6.12.*, 6.12.53, 6.17.3, <5ef9c94d7110e90260c06868cf1dcf899b9f25ee, 0, <1198077606aeffb102587c6ea079ce99641c99d4, <fdd43fe6d286f27b826572457a89c926f97e2d3a, 6.18, <=5.10.*, <=6.6.*, 4.4.34, <1857cdca12c4aff58bf26a7005a4d02850c29927, ac663c54f40b2830b1ca32d1ae9d683fe248b14c, <4.5, <=5.4.*, 5.15.195, <4.9, <91eda032eb16e5d2be27c95584665bc555bb5a90, <e50377c6b3f278c9f3ef017ffce17f5fcc9dace4, 1c7e17b1c4d60cc5aa575460f7efb73686dd3b39, 5.10.246, <=*, 4.9, 6.6.112, <=5.15.*, 6.1.156, <=6.17.*, 5.4.301, 4.8.10, <dc766c4830a7e1e1ee9d7f77d4ab344f2eb23c8e) 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/fdd43fe6d286f27b826572457a89c926f97e2d3a
- https://git.kernel.org/stable/c/1198077606aeffb102587c6ea079ce99641c99d4
- https://git.kernel.org/stable/c/1857cdca12c4aff58bf26a7005a4d02850c29927
- https://git.kernel.org/stable/c/91eda032eb16e5d2be27c95584665bc555bb5a90
- https://git.kernel.org/stable/c/dc766c4830a7e1e1ee9d7f77d4ab344f2eb23c8e
- https://git.kernel.org/stable/c/5ef9c94d7110e90260c06868cf1dcf899b9f25ee
- https://git.kernel.org/stable/c/e50377c6b3f278c9f3ef017ffce17f5fcc9dace4
- https://git.kernel.org/stable/c/47b49c06eb62504075f0f2e2227aee2e2c2a58b3