Skip to content
CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-64233

usb: gadget: uvc: hold opts->lock across XU walks in uvc_function_bind

Read JSON ↗CVE.org ↗
Status
Published
Published
Updated
Assigning organization
Linux

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • 0525210c9840229e42c6b68e886c72a75a67cf8e to < e15c414092b3c24610cc771e481a723b0f645ecaaffected
  • 0525210c9840229e42c6b68e886c72a75a67cf8e to < 2c9e0905ef7e69f7b814cd709613f6b3b5b98805affected
  • 0525210c9840229e42c6b68e886c72a75a67cf8e to < caec0145e5974e85fe5192fc6a6f5aa1a98f82a6affected
  • 0525210c9840229e42c6b68e886c72a75a67cf8e to < 5f1b9cff88982e2a2053d8b1fd983f7ccb9f03ccaffected
  • 0525210c9840229e42c6b68e886c72a75a67cf8e to < 68aa70648b625fa684bc0b71bbfd905f4943ca20affected

Linux Linux

Default version status: affected

  • 6.3affected
  • 0 to < 6.3unaffected
  • 6.6.143 to ≤ 6.6.*unaffected
  • 6.12.93 to ≤ 6.12.*unaffected
  • 6.18.35 to ≤ 6.18.*unaffected
  • 7.0.12 to ≤ 7.0.*unaffected
  • 7.1 to ≤ *unaffected

References