CVE-2026-64233

Description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: uvc: hold opts->lock across XU walks in uvc_function_bind uvc_function_bind() walks &opts->extension_units twice without holding opts->lock: - directly, for the iExtension string-descriptor fixup loop; - indirectly, four times via uvc_copy_descriptors() (once per speed), where the helper iterates uvc->desc.extension_units (which aliases &opts->extension_units) to size and emit XU descriptors. The configfs side (uvcg_extension_make / uvcg_extension_drop, in drivers/usb/gadget/function/uvc_configfs.c) takes opts->lock around its list_add_tail / list_del operations. A privileged userspace process that holds the configfs subtree open and writes the gadget UDC name to bind the function while concurrently rmdir()'ing an extensions subdir can race uvcg_extension_drop() against the bind-time list walks and dereference a freed struct uvcg_extension. Hold opts->lock from the start of the XU string-descriptor fixup through the last uvc_copy_descriptors() call, releasing on the descriptor-error path via a new error_unlock label that drops the lock before falling through to the existing error label. This matches the locking discipline of the configfs callbacks and removes the only remaining unsynchronised reader of the XU list during bind. Reachability: only privileged processes that can mount configfs and write to gadget UDC files can trigger the race, so this is a correctness fix rather than a security boundary.

Gravité et risque d'exploitation

CVE-2026-64233 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 0.11 %, ce qui la place devant 1.4 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <2c9e0905ef7e69f7b814cd709613f6b3b5b98805, <=7.0.*, <=6.12.*, 6.12.93, <5f1b9cff88982e2a2053d8b1fd983f7ccb9f03cc, 0, 6.18.35, <6.3, <=6.6.*, <68aa70648b625fa684bc0b71bbfd905f4943ca20, 6.3, 7.1, <=6.18.*, 7.0.12, <=*, 0525210c9840229e42c6b68e886c72a75a67cf8e, <e15c414092b3c24610cc771e481a723b0f645eca, 6.6.143, <caec0145e5974e85fe5192fc6a6f5aa1a98f82a6) 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/e15c414092b3c24610cc771e481a723b0f645eca
• https://git.kernel.org/stable/c/2c9e0905ef7e69f7b814cd709613f6b3b5b98805
• https://git.kernel.org/stable/c/caec0145e5974e85fe5192fc6a6f5aa1a98f82a6
• https://git.kernel.org/stable/c/5f1b9cff88982e2a2053d8b1fd983f7ccb9f03cc
• https://git.kernel.org/stable/c/68aa70648b625fa684bc0b71bbfd905f4943ca20