Kernel crash via unchecked btusb allocation failure
Published Aug 22, 2025 · Updated May 11, 2026
NULL pointer dereference in Linux kernel 6.16 allows local users to crash the system via a Bluetooth HCI driver operation. The btusb_hci_drv_supported_altsettings() function dereferences rp after kmalloc() returns NULL instead of returning an allocation error. A local low-privileged user must reach the Bluetooth HCI driver while kernel memory allocation fails; the reported impact is a kernel crash only.
Summary
What happened
NULL pointer dereference in Linux kernel 6.16 allows local users to crash the system via a Bluetooth HCI driver operation. The btusb_hci_drv_supported_altsettings() function dereferences rp after kmalloc() returns NULL instead of returning an allocation error. A local low-privileged user must reach the Bluetooth HCI driver while kernel memory allocation fails; the reported impact is a kernel crash only.
The record
- CVE
- CVE-2025-38641
- Published
- Aug 22, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-476, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 22, 2025CVE publishedPublication date reported by the CVE source.
- May 11, 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?
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- Affected versionversion=6.16
- Affected versionversion=7d70989fcea7f79afe018a7e34d3486406c7a94e <5029d80bfc30b60ff57c70ccb04e027acb404f6a
- Affected versionversion=7d70989fcea7f79afe018a7e34d3486406c7a94e <b505902c66a282dcb01bcdc015aa1fdfaaa075db
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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