Kernel panic via missing endpoint descriptor
Published Oct 18, 2026 · Updated Oct 18, 2026
Null dereference in Linux FunctionFS allows local users to crash the kernel via the FUNCTIONFS_ENDPOINT_DESC ioctl. In ffs_epfile_ioctl(), descriptor selection follows the gadget speed without checking whether user space supplied that speed's descriptor before dereferencing it. The trigger requires access to FunctionFS endpoint files and an enabled gadget operating above full speed with only full-speed descriptors supplied; the documented consequence is a kernel panic.
Summary
What happened
Null dereference in Linux FunctionFS allows local users to crash the kernel via the FUNCTIONFS_ENDPOINT_DESC ioctl. In ffs_epfile_ioctl(), descriptor selection follows the gadget speed without checking whether user space supplied that speed's descriptor before dereferencing it. The trigger requires access to FunctionFS endpoint files and an enabled gadget operating above full speed with only full-speed descriptors supplied; the documented consequence is a kernel panic.
The record
- CVE
- CVE-2026-98764
- Published
- Oct 18, 2026
- Updated
- Oct 18, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Oct 18, 2026CVE publishedPublication date reported by the CVE source.
- Oct 18, 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=3.18
- Affected versionversion=c559a353410939c0884e83bdb0e2420a986ac53b <35ab269602e1f7c4c0fe6ea3477264bea77eced3
- Affected versionversion=c559a353410939c0884e83bdb0e2420a986ac53b <7811d8e26c77f8eea79e22d0d14c67ec0658b348
- Affected versionversion=c559a353410939c0884e83bdb0e2420a986ac53b <9cd072788c76595529eb38f42bf94d23852f8534
- Affected versionversion=c559a353410939c0884e83bdb0e2420a986ac53b <9d8761b3c133f6c6a6d3486839dac60e2cf4bfe3
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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Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
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