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CVE-2024-35804

Vulnérabilité élevée dans Linux (Linux)

CVSS 8.8 · Élevée
EPSS 0.2%
Linux•Linux•Versions : <=6.1.*, 5.15.58, 6.6.24, <a9bd6bb6f02bf7132c1ab192ba62bbfa52df7d66, 0, e964665cc7ca13a16992b205fce63554b9efc78b, 5.19, 5.15.154, <9d1b22e573a3789ed1f32033ee709106993ba551, 6.8, b0f294103f4cf733e23d3f0c4e5fd58e42998921, <5.18, <726374dde5d608b15b9756bd52b6fc283fda7a06, <=6.6.*, 1c2361f667f3648855ceae25f1332c18413fdb9f, 5.18.2, <5.15.154, <225d587a073584946c05c9b7651d637bd45c0c71, <910c57dfa4d113aae6571c2a8b9ae8c430975902, <5.19, 5.17.13, 6.7.12, <=*, <=5.15.*, <=6.7.*, 6.1.84, d97c0667c1e61ded6639117b4b9584a9c12b7e66

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Mark target gfn of emulated atomic instruction as dirty When emulating an atomic access on behalf of the guest, mark the target gfn dirty if the CMPXCHG by KVM is attempted and doesn't fault. This fixes a bug where KVM effectively corrupts guest memory during live migration by writing to guest memory without informing userspace that the page is dirty. Marking the page dirty got unintentionally dropped when KVM's emulated CMPXCHG was converted to do a user access. Before that, KVM explicitly mapped the guest page into kernel memory, and marked the page dirty during the unmap phase. Mark the page dirty even if the CMPXCHG fails, as the old data is written back on failure, i.e. the page is still written. The value written is guaranteed to be the same because the operation is atomic, but KVM's ABI is that all writes are dirty logged regardless of the value written. And more importantly, that's what KVM did before the buggy commit. Huge kudos to the folks on the Cc list (and many others), who did all the actual work of triaging and debugging. base-commit: 6769ea8da8a93ed4630f1ce64df6aafcaabfce64

Gravité et risque d'exploitation

CVE-2024-35804 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 13.7 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, 5.15.58, 6.6.24, <a9bd6bb6f02bf7132c1ab192ba62bbfa52df7d66, 0, e964665cc7ca13a16992b205fce63554b9efc78b, 5.19, 5.15.154, <9d1b22e573a3789ed1f32033ee709106993ba551, 6.8, b0f294103f4cf733e23d3f0c4e5fd58e42998921, <5.18, <726374dde5d608b15b9756bd52b6fc283fda7a06, <=6.6.*, 1c2361f667f3648855ceae25f1332c18413fdb9f, 5.18.2, <5.15.154, <225d587a073584946c05c9b7651d637bd45c0c71, <910c57dfa4d113aae6571c2a8b9ae8c430975902, <5.19, 5.17.13, 6.7.12, <=*, <=5.15.*, <=6.7.*, 6.1.84, d97c0667c1e61ded6639117b4b9584a9c12b7e66) 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

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