CVE-2024-42104

Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: add missing check for inode numbers on directory entries Syzbot reported that mounting and unmounting a specific pattern of corrupted nilfs2 filesystem images causes a use-after-free of metadata file inodes, which triggers a kernel bug in lru_add_fn(). As Jan Kara pointed out, this is because the link count of a metadata file gets corrupted to 0, and nilfs_evict_inode(), which is called from iput(), tries to delete that inode (ifile inode in this case). The inconsistency occurs because directories containing the inode numbers of these metadata files that should not be visible in the namespace are read without checking. Fix this issue by treating the inode numbers of these internal files as errors in the sanity check helper when reading directory folios/pages. Also thanks to Hillf Danton and Matthew Wilcox for their initial mm-layer analysis.

Gravité et risque d'exploitation

CVE-2024-42104 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 0.26 %, ce qui la place devant 16.6 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.1.*, 2ba466d74ed74f073257f86e61519cb8f8f46184, 6.10, <07c176e7acc5579c133bb923ab21316d192d0a95, 0, <3ab40870edb883b9633dc5cd55f5a2a11afa618d, 4.19.318, <1b7d549ed2c1fa202c751b69423a0d3a6bd5a180, <=5.10.*, 2.6.30, <2f2fa9cf7c3537958a82fbe8c8595a5eb0861ad7, <=6.6.*, <=6.9.*, <c33c2b0d92aa1c2262d999b2598ad6fbd53bd479, 5.10.222, <b11e8fb93ea5eefb2e4e719497ea177a58ff6131, <=5.4.*, 6.9.9, <2.6.30, <=4.19.*, <265fff1a01cdc083aeaf0d934c929db5cc64aebf, <=*, <=5.15.*, <bb76c6c274683c8570ad788f79d4b875bde0e458, 5.4.280, 5.15.163, 6.1.98, 6.6.39) 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/c33c2b0d92aa1c2262d999b2598ad6fbd53bd479
• https://git.kernel.org/stable/c/07c176e7acc5579c133bb923ab21316d192d0a95
• https://git.kernel.org/stable/c/2f2fa9cf7c3537958a82fbe8c8595a5eb0861ad7
• https://git.kernel.org/stable/c/b11e8fb93ea5eefb2e4e719497ea177a58ff6131
• https://git.kernel.org/stable/c/1b7d549ed2c1fa202c751b69423a0d3a6bd5a180
• https://git.kernel.org/stable/c/3ab40870edb883b9633dc5cd55f5a2a11afa618d
• https://git.kernel.org/stable/c/265fff1a01cdc083aeaf0d934c929db5cc64aebf
• https://git.kernel.org/stable/c/bb76c6c274683c8570ad788f79d4b875bde0e458