Kernel memory corruption via dangling USB request
Published Aug 19, 2025 · Updated Aug 5, 2026
Use-after-free in the Linux USB gadget subsystem allows local users to corrupt kernel memory through a crafted configfs gadget bind. When composite_os_desc_req_prepare() fails to allocate memory, it frees cdev->os_desc_req without clearing the pointer, and composite_dev_cleanup() later dereferences and frees the stale request. Initial-namespace CAP_SYS_ADMIN or delegated gadget-configfs write access is required; exploitation can disclose or overwrite kernel memory or panic the system.
Summary
What happened
Use-after-free in the Linux USB gadget subsystem allows local users to corrupt kernel memory through a crafted configfs gadget bind. When composite_os_desc_req_prepare() fails to allocate memory, it frees cdev->os_desc_req without clearing the pointer, and composite_dev_cleanup() later dereferences and frees the stale request. Initial-namespace CAP_SYS_ADMIN or delegated gadget-configfs write access is required; exploitation can disclose or overwrite kernel memory or panic the system.
The record
- CVE
- CVE-2025-38555
- Published
- Aug 19, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 19, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.16
- Affected versionversion=37a3a533429ef9b3cc9f15a656c19623f0e88df7 <151c0aa896c47a4459e07fee7d4843f44c1bb18e
- Affected versionversion=37a3a533429ef9b3cc9f15a656c19623f0e88df7 <2db29235e900a084a656dea7e0939b0abb7bb897
- Affected versionversion=37a3a533429ef9b3cc9f15a656c19623f0e88df7 <5f06ee9f9a3665d43133f125c17e5258a13f3963
- Affected versionversion=37a3a533429ef9b3cc9f15a656c19623f0e88df7 <8afb22aa063f706f3343707cdfb8cda4d021dd33
- Affected versionversion=37a3a533429ef9b3cc9f15a656c19623f0e88df7 <aada327a9f8028c573636fa60c0abc80fb8135c9
- Affected versionversion=37a3a533429ef9b3cc9f15a656c19623f0e88df7 <bd3c4ef60baf7f65c963f3e12d9d7b2b091e20ba
- Affected versionversion=37a3a533429ef9b3cc9f15a656c19623f0e88df7 <dba96dfa5a0f685b959dd28a52ac8dab0b805204
- Affected versionversion=37a3a533429ef9b3cc9f15a656c19623f0e88df7 <e1be1f380c82a69f80c68c96a7cfe8759fb30355
- Affected versionversion=37a3a533429ef9b3cc9f15a656c19623f0e88df7 <e624bf26127645a2f7821e73fdf6dc64bad07835
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Your stack
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