CVE-2023-52910

Description

In the Linux kernel, the following vulnerability has been resolved: iommu/iova: Fix alloc iova overflows issue In __alloc_and_insert_iova_range, there is an issue that retry_pfn overflows. The value of iovad->anchor.pfn_hi is ~0UL, then when iovad->cached_node is iovad->anchor, curr_iova->pfn_hi + 1 will overflow. As a result, if the retry logic is executed, low_pfn is updated to 0, and then new_pfn < low_pfn returns false to make the allocation successful. This issue occurs in the following two situations: 1. The first iova size exceeds the domain size. When initializing iova domain, iovad->cached_node is assigned as iovad->anchor. For example, the iova domain size is 10M, start_pfn is 0x1_F000_0000, and the iova size allocated for the first time is 11M. The following is the log information, new->pfn_lo is smaller than iovad->cached_node. Example log as follows: [ 223.798112][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range start_pfn:0x1f0000,retry_pfn:0x0,size:0xb00,limit_pfn:0x1f0a00 [ 223.799590][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range success start_pfn:0x1f0000,new->pfn_lo:0x1efe00,new->pfn_hi:0x1f08ff 2. The node with the largest iova->pfn_lo value in the iova domain is deleted, iovad->cached_node will be updated to iovad->anchor, and then the alloc iova size exceeds the maximum iova size that can be allocated in the domain. After judging that retry_pfn is less than limit_pfn, call retry_pfn+1 to fix the overflow issue.

Gravité et risque d'exploitation

CVE-2023-52910 obtient un score CVSS de 8.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.24 %, ce qui la place devant 14.7 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions 6.1.7, <5.11, <=6.1.*, <=*, <c929a230c84441e400c32e7b7b4ab763711fb63e, <=5.15.*, <dcdb3ba7e2a8caae7bfefd603bc22fd0ce9a389c, 4e89dce725213d3d0b0475211b500eda4ef4bf2f, 0, 6.2, 5.11, <61cbf790e7329ed78877560be7136f0b911bba7f, 5.15.89) 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/c929a230c84441e400c32e7b7b4ab763711fb63e
• https://git.kernel.org/stable/c/61cbf790e7329ed78877560be7136f0b911bba7f
• https://git.kernel.org/stable/c/dcdb3ba7e2a8caae7bfefd603bc22fd0ce9a389c