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CVE-2024-26956

Vulnérabilité moyenne dans Linux (Linux)

CVSS 5.5 · Moyenne
EPSS 0.3%
Linux•Linux•Versions : 6.9, <=6.1.*, 0, 5.15.154, 6.8.3, <b67189690eb4b7ecc84ae16fa1e880e0123eaa35, <9cbe1ad5f4354f4df1445e5f4883983328cd6d8e, <=5.10.*, <=6.6.*, 5.10.215, <82827ca21e7c8a91384c5baa656f78a5adfa4ab4, <2.6.31, <2e2619ff5d0def4bb6c2037a32a6eaa28dd95c84, c3a7abf06ce719a51139e62a034590be99abbc2c, <=5.4.*, 4.19.312, <=4.19.*, <f69e81396aea66304d214f175aa371f1b5578862, <a8e4d098de1c0f4c5c1f2ed4633a860f0da6d713, 5.4.274, <=6.8.*, 2.6.31, 6.7.12, <=*, <c3b5c5c31e723b568f83d8cafab8629d9d830ffb, <46b832e09d43b394ac0f6d9485d2b1a06593f0b7, <f2f26b4a84a0ef41791bd2d70861c8eac748f4ba, <=5.15.*, <=6.7.*, 6.1.84, 6.6.24

Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix failure to detect DAT corruption in btree and direct mappings Patch series "nilfs2: fix kernel bug at submit_bh_wbc()". This resolves a kernel BUG reported by syzbot. Since there are two flaws involved, I've made each one a separate patch. The first patch alone resolves the syzbot-reported bug, but I think both fixes should be sent to stable, so I've tagged them as such. This patch (of 2): Syzbot has reported a kernel bug in submit_bh_wbc() when writing file data to a nilfs2 file system whose metadata is corrupted. There are two flaws involved in this issue. The first flaw is that when nilfs_get_block() locates a data block using btree or direct mapping, if the disk address translation routine nilfs_dat_translate() fails with internal code -ENOENT due to DAT metadata corruption, it can be passed back to nilfs_get_block(). This causes nilfs_get_block() to misidentify an existing block as non-existent, causing both data block lookup and insertion to fail inconsistently. The second flaw is that nilfs_get_block() returns a successful status in this inconsistent state. This causes the caller __block_write_begin_int() or others to request a read even though the buffer is not mapped, resulting in a BUG_ON check for the BH_Mapped flag in submit_bh_wbc() failing. This fixes the first issue by changing the return value to code -EINVAL when a conversion using DAT fails with code -ENOENT, avoiding the conflicting condition that leads to the kernel bug described above. Here, code -EINVAL indicates that metadata corruption was detected during the block lookup, which will be properly handled as a file system error and converted to -EIO when passing through the nilfs2 bmap layer.

Gravité et risque d'exploitation

CVE-2024-26956 obtient un score CVSS de 5.5/10, soit une gravité moyenne. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.26 %, ce qui la place devant 16.1 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions 6.9, <=6.1.*, 0, 5.15.154, 6.8.3, <b67189690eb4b7ecc84ae16fa1e880e0123eaa35, <9cbe1ad5f4354f4df1445e5f4883983328cd6d8e, <=5.10.*, <=6.6.*, 5.10.215, <82827ca21e7c8a91384c5baa656f78a5adfa4ab4, <2.6.31, <2e2619ff5d0def4bb6c2037a32a6eaa28dd95c84, c3a7abf06ce719a51139e62a034590be99abbc2c, <=5.4.*, 4.19.312, <=4.19.*, <f69e81396aea66304d214f175aa371f1b5578862, <a8e4d098de1c0f4c5c1f2ed4633a860f0da6d713, 5.4.274, <=6.8.*, 2.6.31, 6.7.12, <=*, <c3b5c5c31e723b568f83d8cafab8629d9d830ffb, <46b832e09d43b394ac0f6d9485d2b1a06593f0b7, <f2f26b4a84a0ef41791bd2d70861c8eac748f4ba, <=5.15.*, <=6.7.*, 6.1.84, 6.6.24) 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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