Kernel crash via invalid gadget buffer count
Published Sep 16, 2026 · Updated Sep 16, 2026
Null pointer dereference in the Linux USB mass-storage gadget allows local users to crash the kernel by writing zero to num_buffers. The configfs store path parses page content with kstrtou8() and passes values below the Kconfig minimum to fsg_common_set_num_buffers(), where zero leaves no buffer object for cyclic-list setup. Reachability requires local write access to the USB gadget configuration interface; the demonstrated outcome is a kernel general-protection fault.
Summary
What happened
Null pointer dereference in the Linux USB mass-storage gadget allows local users to crash the kernel by writing zero to num_buffers. The configfs store path parses page content with kstrtou8() and passes values below the Kconfig minimum to fsg_common_set_num_buffers(), where zero leaves no buffer object for cyclic-list setup. Reachability requires local write access to the USB gadget configuration interface; the demonstrated outcome is a kernel general-protection fault.
The record
- CVE
- CVE-2026-90023
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 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=4.8
- Affected versionversion=fe5a6c48fd954489f51aab151d5dad9254c76419 <2c0f5ca48674a5b5f9fa4a9c3325aa48053af0bc
- Affected versionversion=fe5a6c48fd954489f51aab151d5dad9254c76419 <9e8dd2a7a8ccbb756771ad985b0ad3387ed3c957
- Affected versionversion=fe5a6c48fd954489f51aab151d5dad9254c76419 <b9b5b5df5b8dd3c1572ed267200276a44cc67d8e
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
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
- syzbot C reproducer for fsg_common_set_num_buffers faultproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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