CVE-2022-49913

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix inode list leak during backref walking at find_parent_nodes() During backref walking, at find_parent_nodes(), if we are dealing with a data extent and we get an error while resolving the indirect backrefs, at resolve_indirect_refs(), or in the while loop that iterates over the refs in the direct refs rbtree, we end up leaking the inode lists attached to the direct refs we have in the direct refs rbtree that were not yet added to the refs ulist passed as argument to find_parent_nodes(). Since they were not yet added to the refs ulist and prelim_release() does not free the lists, on error the caller can only free the lists attached to the refs that were added to the refs ulist, all the remaining refs get their inode lists never freed, therefore leaking their memory. Fix this by having prelim_release() always free any attached inode list to each ref found in the rbtree, and have find_parent_nodes() set the ref's inode list to NULL once it transfers ownership of the inode list to a ref added to the refs ulist passed to find_parent_nodes().

Gravité et risque d'exploitation

CVE-2022-49913 obtient un score CVSS de 0.0/10, soit une gravité non évaluée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.20 %, ce qui la place devant 9.4 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <6a6731a0df8c47ecc703bd7bb73459df767051e0, 5.10.154, 0, 6.0.8, <83ea8c5b54d452a5769e605e3c5c687e8ca06d89, <=5.10.*, <=6.0.*, <92876eec382a0f19f33d09d2c939e9ca49038ae5, <=5.4.*, 5.15.78, 6.1, 5.4.224, <61e06128113711df0534c404fb6bb528eb7d2332, <=*, <4.14, <=5.15.*, 86d5f994425252d8a40e2184c94a2682ae8ecfbf, 4.14, <222a3d533027b9492d5b7f5ecdc01a90f57bb5a9) 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/6a6731a0df8c47ecc703bd7bb73459df767051e0
• https://git.kernel.org/stable/c/61e06128113711df0534c404fb6bb528eb7d2332
• https://git.kernel.org/stable/c/222a3d533027b9492d5b7f5ecdc01a90f57bb5a9
• https://git.kernel.org/stable/c/83ea8c5b54d452a5769e605e3c5c687e8ca06d89
• https://git.kernel.org/stable/c/92876eec382a0f19f33d09d2c939e9ca49038ae5