CVE-2023-52609

Description

In the Linux kernel, the following vulnerability has been resolved: binder: fix race between mmput() and do_exit() Task A calls binder_update_page_range() to allocate and insert pages on a remote address space from Task B. For this, Task A pins the remote mm via mmget_not_zero() first. This can race with Task B do_exit() and the final mmput() refcount decrement will come from Task A. Task A | Task B ------------------+------------------ mmget_not_zero() | | do_exit() | exit_mm() | mmput() mmput() | exit_mmap() | remove_vma() | fput() | In this case, the work of ____fput() from Task B is queued up in Task A as TWA_RESUME. So in theory, Task A returns to userspace and the cleanup work gets executed. However, Task A instead sleep, waiting for a reply from Task B that never comes (it's dead). This means the binder_deferred_release() is blocked until an unrelated binder event forces Task A to go back to userspace. All the associated death notifications will also be delayed until then. In order to fix this use mmput_async() that will schedule the work in the corresponding mm->async_put_work WQ instead of Task A.

Gravité et risque d'exploitation

CVE-2023-52609 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 0.18 %, ce qui la place devant 7.7 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.1.*, <2.6.29, <252a2a5569eb9f8d16428872cc24dea1ac0bb097, <6696f76c32ff67fec26823fc2df46498e70d9bf3, 5.15.148, 0, 457b9a6f09f011ebcb9b52cc203a6331a6fc2de7, 6.6.14, 6.8, 6.1.75, 2.6.29, 5.4.268, <=5.10.*, <=6.6.*, <9a9ab0d963621d9d12199df9817e66982582d5a5, <=5.4.*, <=4.19.*, <95b1d336b0642198b56836b89908d07b9a0c9608, 6.7.2, <67f16bf2cc1698fd50e01ee8a2becc5a8e6d3a3e, <7e7a0d86542b0ea903006d3f42f33c4f7ead6918, <=*, <=5.15.*, 5.10.209, <=6.7.*, <77d210e8db4d61d43b2d16df66b1ec46fad2ee01, 4.19.306, <98fee5bee97ad47b527a997d5786410430d1f0e9) 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/95b1d336b0642198b56836b89908d07b9a0c9608
• https://git.kernel.org/stable/c/252a2a5569eb9f8d16428872cc24dea1ac0bb097
• https://git.kernel.org/stable/c/7e7a0d86542b0ea903006d3f42f33c4f7ead6918
• https://git.kernel.org/stable/c/98fee5bee97ad47b527a997d5786410430d1f0e9
• https://git.kernel.org/stable/c/6696f76c32ff67fec26823fc2df46498e70d9bf3
• https://git.kernel.org/stable/c/67f16bf2cc1698fd50e01ee8a2becc5a8e6d3a3e
• https://git.kernel.org/stable/c/77d210e8db4d61d43b2d16df66b1ec46fad2ee01
• https://git.kernel.org/stable/c/9a9ab0d963621d9d12199df9817e66982582d5a5