CVE-2023-53421
Vulnérabilité moyenne dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: Reinit blkg_iostat_set after clearing in blkcg_reset_stats() When blkg_alloc() is called to allocate a blkcg_gq structure with the associated blkg_iostat_set's, there are 2 fields within blkg_iostat_set that requires proper initialization - blkg & sync. The former field was introduced by commit 3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()") while the later one was introduced by commit f73316482977 ("blk-cgroup: reimplement basic IO stats using cgroup rstat"). Unfortunately those fields in the blkg_iostat_set's are not properly re-initialized when they are cleared in v1's blkcg_reset_stats(). This can lead to a kernel panic due to NULL pointer access of the blkg pointer. The missing initialization of sync is less problematic and can be a problem in a debug kernel due to missing lockdep initialization. Fix these problems by re-initializing them after memory clearing.
Gravité et risque d'exploitation
CVE-2023-53421 obtient un score CVSS de 5.5/10, soit une gravité moyenne. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.17 %, ce qui la place devant 5.3 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <=6.1.*, 6.3.13, <b0d26283af612b9e0cc3188b0b88ad7fdea447e8, <3d2af77e31ade05ff7ccc3658c3635ec1bea0979, f73316482977ac401ac37245c9df48079d4e11f3, 0, <=6.3.*, 5.15.199, <58c135513562698f222a58ba07dbdfcfb268aa0d, <892faa76be894d324bf48b12a55c7af7be2bad83, 6.5, <=5.10.*, <5.5, 6.1.162, 5.5, 5.10.258, 6.4.4, <=*, <=5.15.*, <abbce7f82613ea5eeefd0fc3c1c8e449b9cef2a2, <0561aa6033dd181594116d705c41fc16e97161a2, <=6.4.*) 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/58c135513562698f222a58ba07dbdfcfb268aa0d
- https://git.kernel.org/stable/c/0561aa6033dd181594116d705c41fc16e97161a2
- https://git.kernel.org/stable/c/892faa76be894d324bf48b12a55c7af7be2bad83
- https://git.kernel.org/stable/c/b0d26283af612b9e0cc3188b0b88ad7fdea447e8
- https://git.kernel.org/stable/c/abbce7f82613ea5eeefd0fc3c1c8e449b9cef2a2
- https://git.kernel.org/stable/c/3d2af77e31ade05ff7ccc3658c3635ec1bea0979