Return-value corruption via oversized BPF trampoline returns
Published Sep 17, 2026 · Updated Sep 17, 2026
Return-value corruption in Linux BPF allows local users to alter kernel function results via return-reading trampoline attachments. btf_distill_func_proto() accepts 16-byte __int128 returns although the trampoline preserves only eight bytes, leaving the upper half unsaved and unrestored. Exploitation requires privileged BPF attachment through fexit, fmod_ret, fsession, their affected multi variants, or struct_ops; fentry paths are unaffected, and no privilege escalation is established.
Summary
What happened
Return-value corruption in Linux BPF allows local users to alter kernel function results via return-reading trampoline attachments. btf_distill_func_proto() accepts 16-byte __int128 returns although the trampoline preserves only eight bytes, leaving the upper half unsaved and unrestored. Exploitation requires privileged BPF attachment through fexit, fmod_ret, fsession, their affected multi variants, or struct_ops; fentry paths are unaffected, and no privilege escalation is established.
The record
- CVE
- CVE-2026-90359
- Published
- Sep 17, 2026
- Updated
- Sep 17, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Sep 17, 2026CVE publishedPublication date reported by the CVE source.
- Sep 17, 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=5.5
- Affected versionversion=fec56f5890d93fc2ed74166c397dc186b1c25951 <c48796aa6c392cde93946e5d5a9a1f1b1cf72feb
- Affected versionversion=fec56f5890d93fc2ed74166c397dc186b1c25951 <d36ac53fc83baf843c51b7afd6d2471f36b713d8
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
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Public exploit references
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Technologies
Your stack
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