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CVE-2026-74601

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.8 · Élevée
EPSS 0.1%
Linux•Linux•Versions : <=6.1.*, <=6.12.*, <5b926fb04cb9ef3156dcf88c69a59d3d1a1c4f9f, 5.15.217, 0, <=7.1.*, 4239c38fe0b3847e1e6d962c74b41b08ba0e2990, <597f279b7b4a06412e3d965e98cc36e181cdbede, <=5.10.*, <=6.6.*, <5e6e2a18c20e88167d414f666032792e8bf19b80, 7.1.9, <22709117d9ae95e52673685f98caac7c356a8227, <26662bc8fced1d668fa1aa146eda085bfc67bd0b, 5.10.266, <4.5, <=6.18.*, 6.1.184, <6b524e6b234e45c7f5f90d13b042c6f57f80105c, 6.18.45, <f27bdc43077e4fcb5557dfc315ee8d91e741f483, <=*, 4.5, <=5.15.*, 6.6.153, <ad7e10c7ea89af45ac1bf1814855d45da472703d, 6.12.105, 7.2

Description

In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Use current_context for safe per-CPU buffer swap The ring_buffer_swap_cpu() function currently checks the per-CPU committing counter to determine if a buffer is actively being written to before performing the swap. However, there exists a race window where this check can be bypassed: ring_buffer_lock_reserve cpu_buffer = buffer->buffers[cpu]; // cpu_buffer_a rb_reserve_next_event rb_start_commit // inc committing if (unlikely(READ_ONCE(cpu_buffer->buffer) != buffer)) {...} __rb_reserve_next rb_move_tail rb_end_commit(cpu_buffer); // dec committing => 0 /* interrupt hits here, successfully swaps! */ local_inc(&cpu_buffer->committing); ring_buffer_unlock_commit cpu_buffer = buffer->buffers[cpu]; // cpu_buffer_b rb_commit rb_end_commit RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing)) // triggers warning The committing counter can temporarily drop to 0 during a single write operation (within rb_move_tail), creating a window where swap can succeed even though the write is still in progress. This leads to inconsistent buffer state and triggers the RB_WARN_ON in rb_commit(). Replace the committing counter check with current_context checks, which are set at the entry of ring_buffer_lock_reserve() and remain valid throughout the entire write operation, providing a reliable indicator of buffer busy state during swap.

Gravité et risque d'exploitation

CVE-2026-74601 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 0.14 %, ce qui la place devant 2.7 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, <=6.12.*, <5b926fb04cb9ef3156dcf88c69a59d3d1a1c4f9f, 5.15.217, 0, <=7.1.*, 4239c38fe0b3847e1e6d962c74b41b08ba0e2990, <597f279b7b4a06412e3d965e98cc36e181cdbede, <=5.10.*, <=6.6.*, <5e6e2a18c20e88167d414f666032792e8bf19b80, 7.1.9, <22709117d9ae95e52673685f98caac7c356a8227, <26662bc8fced1d668fa1aa146eda085bfc67bd0b, 5.10.266, <4.5, <=6.18.*, 6.1.184, <6b524e6b234e45c7f5f90d13b042c6f57f80105c, 6.18.45, <f27bdc43077e4fcb5557dfc315ee8d91e741f483, <=*, 4.5, <=5.15.*, 6.6.153, <ad7e10c7ea89af45ac1bf1814855d45da472703d, 6.12.105, 7.2) 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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