Heimdall Security Logo

CVE-2026-72170

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.8 · Élevée
EPSS 0.2%
Linux•Linux•Versions : <=6.1.*, 7.1.5, 6.18.40, <=6.12.*, <8d610017c992de705b304d3d727a6e3a86af6149, 5.15.217, <574aa0b4799470ac814479f1138d19efe6262255, 0, <=7.1.*, <ab257019cb72f467b55c95384d99c94e3908b928, <4.17, <=5.10.*, <=6.6.*, <4ec4ebe40c82cb4c60756732f6593055d010c59c, <de79c3f3643841b8659a71958df7cf2a66bfd409, 6.12.97, 5.10.266, 4.17, <=6.18.*, <a5a682b016ef5b5384e28f6d652d47a8f8e73d37, 6.1.184, 6.6.145, <6086469f7d469549bfd070348b717a6e43736200, ac89b2ef9b55924bcf922251f043ba73a32d05bb, <=*, <=5.15.*, 7.2, <8faccac11e1369adddf5d80f4a45af93f13b2e1a

Description

In the Linux kernel, the following vulnerability has been resolved: 9p: skip nlink update in cacheless mode to fix WARN_ON v9fs_dec_count() unconditionally calls drop_nlink() on regular files, even when the inode's nlink is already zero. In cacheless mode the client refetches inode metadata from the server (the source of truth) on every operation, so by the time v9fs_remove() returns, the locally cached nlink may already reflect the post-unlink value: 1. Client initiates unlink, server processes it and sets nlink to 0 2. Client refetches inode metadata (nlink=0) before unlink returns 3. Client's v9fs_remove() completes successfully 4. Client calls v9fs_dec_count() which calls drop_nlink() on nlink=0 This race is easily triggered under heavy unlink workloads, such as stress-ng's unlink stressor, producing the following warning: WARNING: fs/inode.c:417 at drop_nlink+0x4c/0xc8 Call trace: drop_nlink+0x4c/0xc8 v9fs_remove+0x1e0/0x250 [9p] v9fs_vfs_unlink+0x20/0x38 [9p] vfs_unlink+0x13c/0x258 ... In cacheless mode the server is authoritative and the inode is on its way out, so locally adjusting nlink buys nothing. Skip v9fs_dec_count() entirely when neither CACHE_META nor CACHE_LOOSE is set, which both avoids the warning and removes a class of nlink races (two concurrent unlinkers observing nlink > 0 and both calling drop_nlink()) that an nlink == 0 guard alone would only narrow rather than close.

Gravité et risque d'exploitation

CVE-2026-72170 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 5.8 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, 7.1.5, 6.18.40, <=6.12.*, <8d610017c992de705b304d3d727a6e3a86af6149, 5.15.217, <574aa0b4799470ac814479f1138d19efe6262255, 0, <=7.1.*, <ab257019cb72f467b55c95384d99c94e3908b928, <4.17, <=5.10.*, <=6.6.*, <4ec4ebe40c82cb4c60756732f6593055d010c59c, <de79c3f3643841b8659a71958df7cf2a66bfd409, 6.12.97, 5.10.266, 4.17, <=6.18.*, <a5a682b016ef5b5384e28f6d652d47a8f8e73d37, 6.1.184, 6.6.145, <6086469f7d469549bfd070348b717a6e43736200, ac89b2ef9b55924bcf922251f043ba73a32d05bb, <=*, <=5.15.*, 7.2, <8faccac11e1369adddf5d80f4a45af93f13b2e1a) 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

Rechercher une autre CVE