CVE-2026-64233
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Record status
- Analyzed
Affected
- Linux Kernel < 6.6.143
- Linux Kernel < 6.12.93
- Linux Kernel < 6.18.35
- Linux Kernel < 7.0.12
- Linux Kernel 7.1
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-64233.md and follow it. Check whether this project is affected by CVE-2026-64233. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/2c9e0905ef7e69f7b814cd709613f6b3b5b98805
- https://git.kernel.org/stable/c/5f1b9cff88982e2a2053d8b1fd983f7ccb9f03cc
- https://git.kernel.org/stable/c/68aa70648b625fa684bc0b71bbfd905f4943ca20
- https://git.kernel.org/stable/c/caec0145e5974e85fe5192fc6a6f5aa1a98f82a6
- https://git.kernel.org/stable/c/e15c414092b3c24610cc771e481a723b0f645eca
References
- https://git.kernel.org/stable/c/2c9e0905ef7e69f7b814cd709613f6b3b5b98805
- https://git.kernel.org/stable/c/5f1b9cff88982e2a2053d8b1fd983f7ccb9f03cc
- https://git.kernel.org/stable/c/68aa70648b625fa684bc0b71bbfd905f4943ca20
- https://git.kernel.org/stable/c/caec0145e5974e85fe5192fc6a6f5aa1a98f82a6
- https://git.kernel.org/stable/c/e15c414092b3c24610cc771e481a723b0f645eca