CVE-2022-49939

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.8 · Élevée
EPSS 0.2%
Linux•Linux•Versions : <9629f2dfdb1dad294b468038ff8e161e94d0b609, 4.14.293, 5.4.213, 5.10.142, <229f47603dd306bc0eb1a831439adb8e48bb0eae, 0, 4.19.258, <603a47f2ae56bf68288784d3c0a8c5b8e0a827ed, <06e5b43ca4dab06a92bf4c2f33766e6fb11b880a, <=4.14.*, <=5.10.*, <c2a4b5dc8fa71af73bab704d0cac42ac39767ed6, 6.0, 5.15.66, <=5.4.*, 5.19.8, <=4.19.*, <30d0901b307f27d36b2655fb3048cf31ee0e89c0, <=*, <a0e44c64b6061dda7e00b7c458e4523e2331b739, <4.14, <=5.15.*, 372e3147df7016ebeaa372939e8774a1292db558, <=5.19.*, 4.14

Description

In the Linux kernel, the following vulnerability has been resolved: binder: fix UAF of ref->proc caused by race condition A transaction of type BINDER_TYPE_WEAK_HANDLE can fail to increment the reference for a node. In this case, the target proc normally releases the failed reference upon close as expected. However, if the target is dying in parallel the call will race with binder_deferred_release(), so the target could have released all of its references by now leaving the cleanup of the new failed reference unhandled. The transaction then ends and the target proc gets released making the ref->proc now a dangling pointer. Later on, ref->node is closed and we attempt to take spin_lock(&ref->proc->inner_lock), which leads to the use-after-free bug reported below. Let's fix this by cleaning up the failed reference on the spot instead of relying on the target to do so. ================================================================== BUG: KASAN: use-after-free in _raw_spin_lock+0xa8/0x150 Write of size 4 at addr ffff5ca207094238 by task kworker/1:0/590 CPU: 1 PID: 590 Comm: kworker/1:0 Not tainted 5.19.0-rc8 #10 Hardware name: linux,dummy-virt (DT) Workqueue: events binder_deferred_func Call trace: dump_backtrace.part.0+0x1d0/0x1e0 show_stack+0x18/0x70 dump_stack_lvl+0x68/0x84 print_report+0x2e4/0x61c kasan_report+0xa4/0x110 kasan_check_range+0xfc/0x1a4 __kasan_check_write+0x3c/0x50 _raw_spin_lock+0xa8/0x150 binder_deferred_func+0x5e0/0x9b0 process_one_work+0x38c/0x5f0 worker_thread+0x9c/0x694 kthread+0x188/0x190 ret_from_fork+0x10/0x20

Gravité et risque d'exploitation

CVE-2022-49939 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 0.17 %, ce qui la place devant 5.7 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <9629f2dfdb1dad294b468038ff8e161e94d0b609, 4.14.293, 5.4.213, 5.10.142, <229f47603dd306bc0eb1a831439adb8e48bb0eae, 0, 4.19.258, <603a47f2ae56bf68288784d3c0a8c5b8e0a827ed, <06e5b43ca4dab06a92bf4c2f33766e6fb11b880a, <=4.14.*, <=5.10.*, <c2a4b5dc8fa71af73bab704d0cac42ac39767ed6, 6.0, 5.15.66, <=5.4.*, 5.19.8, <=4.19.*, <30d0901b307f27d36b2655fb3048cf31ee0e89c0, <=*, <a0e44c64b6061dda7e00b7c458e4523e2331b739, <4.14, <=5.15.*, 372e3147df7016ebeaa372939e8774a1292db558, <=5.19.*, 4.14) 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