CVE-2024-26704
Vulnérabilité élevée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: ext4: fix double-free of blocks due to wrong extents moved_len In ext4_move_extents(), moved_len is only updated when all moves are successfully executed, and only discards orig_inode and donor_inode preallocations when moved_len is not zero. When the loop fails to exit after successfully moving some extents, moved_len is not updated and remains at 0, so it does not discard the preallocations. If the moved extents overlap with the preallocated extents, the overlapped extents are freed twice in ext4_mb_release_inode_pa() and ext4_process_freed_data() (as described in commit 94d7c16cbbbd ("ext4: Fix double-free of blocks with EXT4_IOC_MOVE_EXT")), and bb_free is incremented twice. Hence when trim is executed, a zero-division bug is triggered in mb_update_avg_fragment_size() because bb_free is not zero and bb_fragments is zero. Therefore, update move_len after each extent move to avoid the issue.
Gravité et risque d'exploitation
CVE-2024-26704 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 0.27 %, ce qui la place devant 17.8 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions 6.6.18, <=6.1.*, <55583e899a5357308274601364741a83e78d6ac4, 0, <185eab30486ba3e7bf8b9c2e049c79a06ffd2bc1, 6.8, <afba9d11320dad5ce222ac8964caf64b7b4bedb1, <=5.10.*, <=6.6.*, <b4fbb89d722cbb16beaaea234b7230faaaf68c71, <d033a555d9a1cf53dbf3301af7199cc4a4c8f537, 5.15.149, <2883940b19c38d5884c8626483811acf4d7e148f, <=5.4.*, <afbcad9ae7d6d11608399188f03a837451b6b3a1, fcf6b1b729bcd23f2b49a84fb33ffbb44712ee6a, <=4.19.*, <3.18, 4.19.307, 5.4.269, 6.1.79, 5.10.210, 6.7.6, <=*, <=5.15.*, <=6.7.*, <559ddacb90da1d8786dd8ec4fd76bbfa404eaef6, 3.18) 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/b4fbb89d722cbb16beaaea234b7230faaaf68c71
- https://git.kernel.org/stable/c/afbcad9ae7d6d11608399188f03a837451b6b3a1
- https://git.kernel.org/stable/c/d033a555d9a1cf53dbf3301af7199cc4a4c8f537
- https://git.kernel.org/stable/c/afba9d11320dad5ce222ac8964caf64b7b4bedb1
- https://git.kernel.org/stable/c/185eab30486ba3e7bf8b9c2e049c79a06ffd2bc1
- https://git.kernel.org/stable/c/2883940b19c38d5884c8626483811acf4d7e148f
- https://git.kernel.org/stable/c/559ddacb90da1d8786dd8ec4fd76bbfa404eaef6
- https://git.kernel.org/stable/c/55583e899a5357308274601364741a83e78d6ac4