Kernel warning via direct-mode CQ reset callback
Published Aug 28, 2026 · Updated Aug 28, 2026
Improper callback invocation in Linux 5.5 and later allows attackers to trigger a kernel warning during an HNS RoCE device reset. hns_roce_cq_completion calls the completion handler of an ib_alloc_cq direct-mode completion queue even though that handler must not run in direct mode, reaching ib_cq_completion_direct and its WARN_ONCE. Reachability requires the HNS RoCE driver, a direct-mode completion queue, and a device reset; published evidence documents the warning but no crash, data access, or privilege gain.
Summary
What happened
Improper callback invocation in Linux 5.5 and later allows attackers to trigger a kernel warning during an HNS RoCE device reset. hns_roce_cq_completion calls the completion handler of an ib_alloc_cq direct-mode completion queue even though that handler must not run in direct mode, reaching ib_cq_completion_direct and its WARN_ONCE. Reachability requires the HNS RoCE driver, a direct-mode completion queue, and a device reset; published evidence documents the warning but no crash, data access, or privilege gain.
The record
- CVE
- CVE-2026-80647
- Published
- Aug 28, 2026
- Updated
- Aug 28, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Aug 28, 2026CVE publishedPublication date reported by the CVE source.
- Aug 28, 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=5.5
- Affected versionversion=f295e4cece5cb4c60715fed539abcd62468f9ef1 <16138ea9833d6bb1bed37a3321f282242704bf02
- Affected versionversion=f295e4cece5cb4c60715fed539abcd62468f9ef1 <1e56f8886d64288cf88d80af44c7b9148aeaa98b
- Affected versionversion=f295e4cece5cb4c60715fed539abcd62468f9ef1 <3f19c2a3852e6ba75f3e92dd5edc4e07f3d07f4a
- Affected versionversion=f295e4cece5cb4c60715fed539abcd62468f9ef1 <95b2e44bc1e5c5d93bb58e178d914dd99a3baa6f
- Affected versionversion=f295e4cece5cb4c60715fed539abcd62468f9ef1 <9f05319149c14acedb83e2c2842ec4b38992ad9f
- Affected versionversion=f295e4cece5cb4c60715fed539abcd62468f9ef1 <a075a7acd155ffdd058e72eb3f4cce1207ebafa1
- Affected versionversion=f295e4cece5cb4c60715fed539abcd62468f9ef1 <c028c1977b6e61eee26bb69332453efb6513f83b
- Affected versionversion=f295e4cece5cb4c60715fed539abcd62468f9ef1 <e7d363c0ffa836ac1d89657686cad241392c5eb2
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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