Device-discovery disruption via empty-bus mask computation
Published Sep 11, 2026 · Updated Sep 11, 2026
Out-of-bounds access in the Renesas I3C master driver in Linux 7.0 allows attackers to disrupt device discovery on an empty bus. The driver treats NRSPQP's maximum remaining-device count as a valid basis for the newdevs bitmask instead of recognizing the empty-bus result, causing the computation to exceed valid bounds. The path is reached when software initiates Dynamic Address Assignment on a system using the Renesas controller with no I3C devices attached; no broader confidentiality or integrity impact is reported.
Summary
What happened
Out-of-bounds access in the Renesas I3C master driver in Linux 7.0 allows attackers to disrupt device discovery on an empty bus. The driver treats NRSPQP's maximum remaining-device count as a valid basis for the newdevs bitmask instead of recognizing the empty-bus result, causing the computation to exceed valid bounds. The path is reached when software initiates Dynamic Address Assignment on a system using the Renesas controller with no I3C devices attached; no broader confidentiality or integrity impact is reported.
The record
- CVE
- CVE-2026-89728
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 11, 2026CVE publishedPublication date reported by the CVE source.
- Sep 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=7.0
- Affected versionversion=e7218986319b4e903dfb4642dcbd1087cf16aaec <50dec95c9d1f1f82819bc898ef2b60fa83fd4ccd
- Affected versionversion=e7218986319b4e903dfb4642dcbd1087cf16aaec <769f5a233efcf8587f70fb2244a202d88582c746
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Public exploit references
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Technologies
Your stack
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Your stack
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