CVE-2024-56619

Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix potential out-of-bounds memory access in nilfs_find_entry() Syzbot reported that when searching for records in a directory where the inode's i_size is corrupted and has a large value, memory access outside the folio/page range may occur, or a use-after-free bug may be detected if KASAN is enabled. This is because nilfs_last_byte(), which is called by nilfs_find_entry() and others to calculate the number of valid bytes of directory data in a page from i_size and the page index, loses the upper 32 bits of the 64-bit size information due to an inappropriate type of local variable to which the i_size value is assigned. This caused a large byte offset value due to underflow in the end address calculation in the calling nilfs_find_entry(), resulting in memory access that exceeds the folio/page size. Fix this issue by changing the type of the local variable causing the bit loss from "unsigned int" to "u64". The return value of nilfs_last_byte() is also of type "unsigned int", but it is truncated so as not to exceed PAGE_SIZE and no bit loss occurs, so no change is required.

Gravité et risque d'exploitation

CVE-2024-56619 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 0.21 %, ce qui la place devant 10.9 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions 6.13, <=6.1.*, <=6.12.*, 2ba466d74ed74f073257f86e61519cb8f8f46184, 0, 6.1.120, <c3afea07477baccdbdec4483f8d5e59d42a3f67f, 5.10.231, 5.15.174, <=5.10.*, 2.6.30, <=6.6.*, 6.12.5, <09d6d05579fd46e61abf6e457bb100ff11f3a9d3, <31f7b57a77d4c82a34ddcb6ff35b5aa577ef153e, 6.6.66, <=5.4.*, <2.6.30, <5af8366625182f01f6d8465c9a3210574673af57, <=*, <=5.15.*, 5.4.287, <985ebec4ab0a28bb5910c3b1481a40fbf7f9e61d, <48eb6e7404948032bbe811c5affbe39f6b316951, <e3732102a9d638d8627d14fdf7b208462f0520e0) 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/09d6d05579fd46e61abf6e457bb100ff11f3a9d3
• https://git.kernel.org/stable/c/e3732102a9d638d8627d14fdf7b208462f0520e0
• https://git.kernel.org/stable/c/48eb6e7404948032bbe811c5affbe39f6b316951
• https://git.kernel.org/stable/c/5af8366625182f01f6d8465c9a3210574673af57
• https://git.kernel.org/stable/c/c3afea07477baccdbdec4483f8d5e59d42a3f67f
• https://git.kernel.org/stable/c/31f7b57a77d4c82a34ddcb6ff35b5aa577ef153e
• https://git.kernel.org/stable/c/985ebec4ab0a28bb5910c3b1481a40fbf7f9e61d