CVE-2024-26812

Description

In the Linux kernel, the following vulnerability has been resolved: vfio/pci: Create persistent INTx handler A vulnerability exists where the eventfd for INTx signaling can be deconfigured, which unregisters the IRQ handler but still allows eventfds to be signaled with a NULL context through the SET_IRQS ioctl or through unmask irqfd if the device interrupt is pending. Ideally this could be solved with some additional locking; the igate mutex serializes the ioctl and config space accesses, and the interrupt handler is unregistered relative to the trigger, but the irqfd path runs asynchronous to those. The igate mutex cannot be acquired from the atomic context of the eventfd wake function. Disabling the irqfd relative to the eventfd registration is potentially incompatible with existing userspace. As a result, the solution implemented here moves configuration of the INTx interrupt handler to track the lifetime of the INTx context object and irq_type configuration, rather than registration of a particular trigger eventfd. Synchronization is added between the ioctl path and eventfd_signal() wrapper such that the eventfd trigger can be dynamically updated relative to in-flight interrupts or irqfd callbacks.

Gravité et risque d'exploitation

CVE-2024-26812 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 0.25 %, ce qui la place devant 15.4 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions 6.9, <=6.1.*, 89e1f7d4c66d85f42c3d52ea3866eb10cadf6153, 0, <4c089cefe30924fbe20dd1ee92774ea1f5eca834, 5.15.154, <3.6, 6.8.3, <=5.10.*, <=6.6.*, 3.6, 5.10.215, <18c198c96a815c962adc2b9b77909eec0be7df4d, <=5.4.*, <4cb0d7532126d23145329826c38054b4e9a05e7c, <69276a555c740acfbff13fb5769ee9c92e1c828e, 5.4.274, <=6.8.*, <b18fa894d615c8527e15d96b76c7448800e13899, 6.7.12, <=*, <=5.15.*, <=6.7.*, <27d40bf72dd9a6600b76ad05859176ea9a1b4897, 6.1.84, <7d29d4c72c1e196cce6969c98072a272d1a703b3, <0e09cf81959d9f12b75ad5c6dd53d237432ed034, 6.6.24) 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/b18fa894d615c8527e15d96b76c7448800e13899
• https://git.kernel.org/stable/c/27d40bf72dd9a6600b76ad05859176ea9a1b4897
• https://git.kernel.org/stable/c/4cb0d7532126d23145329826c38054b4e9a05e7c
• https://git.kernel.org/stable/c/7d29d4c72c1e196cce6969c98072a272d1a703b3
• https://git.kernel.org/stable/c/69276a555c740acfbff13fb5769ee9c92e1c828e
• https://git.kernel.org/stable/c/4c089cefe30924fbe20dd1ee92774ea1f5eca834
• https://git.kernel.org/stable/c/0e09cf81959d9f12b75ad5c6dd53d237432ed034
• https://git.kernel.org/stable/c/18c198c96a815c962adc2b9b77909eec0be7df4d