CVE-2023-54225

Description

In the Linux kernel, the following vulnerability has been resolved: net: ipa: only reset hashed tables when supported Last year, the code that manages GSI channel transactions switched from using spinlock-protected linked lists to using indexes into the ring buffer used for a channel. Recently, Google reported seeing transaction reference count underflows occasionally during shutdown. Doug Anderson found a way to reproduce the issue reliably, and bisected the issue to the commit that eliminated the linked lists and the lock. The root cause was ultimately determined to be related to unused transactions being committed as part of the modem shutdown cleanup activity. Unused transactions are not normally expected (except in error cases). The modem uses some ranges of IPA-resident memory, and whenever it shuts down we zero those ranges. In ipa_filter_reset_table() a transaction is allocated to zero modem filter table entries. If hashing is not supported, hashed table memory should not be zeroed. But currently nothing prevents that, and the result is an unused transaction. Something similar occurs when we zero routing table entries for the modem. By preventing any attempt to clear hashed tables when hashing is not supported, the reference count underflow is avoided in this case. Note that there likely remains an issue with properly freeing unused transactions (if they occur due to errors). This patch addresses only the underflows that Google originally reported.

Gravité et risque d'exploitation

CVE-2023-54225 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 8.9 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <e11ec2b868af2b351c6c1e2e50eb711cc5423a10, <=6.1.*, <=*, 6.1.45, <50c24f0c940728792c8bdf65c1eaf6b91b3b0dcd, 6.5, 0, d338ae28d8a866c57fcac38f3d77bcc1d1702d19, 6.1, 6.4.8, <c00af3a818cc573e10100cc6770f0e47befa1fa4, <6.1, <=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/50c24f0c940728792c8bdf65c1eaf6b91b3b0dcd
• https://git.kernel.org/stable/c/c00af3a818cc573e10100cc6770f0e47befa1fa4
• https://git.kernel.org/stable/c/e11ec2b868af2b351c6c1e2e50eb711cc5423a10