Kernel-memory disclosure via signed-length expansion
Published Jun 19, 2024 · Updated Aug 5, 2026
Out-of-bounds read in Linux allows local users to disclose kernel memory or crash the host through crafted SCSI commands. In resp_readcap16, an int-typed min_t sign-extends the requested allocation length, selects an oversized copy length, and drives sg_copy_from_buffer past the response buffer. Exploitation requires scsi_debug to be loaded and access to its SCSI generic device; the resulting over-read exposes kernel memory or triggers a kernel panic.
Summary
What happened
Out-of-bounds read in Linux allows local users to disclose kernel memory or crash the host through crafted SCSI commands. In resp_readcap16, an int-typed min_t sign-extends the requested allocation length, selects an oversized copy length, and drives sg_copy_from_buffer past the response buffer. Exploitation requires scsi_debug to be loaded and access to its SCSI generic device; the resulting over-read exposes kernel memory or triggers a kernel panic.
The record
- CVE
- CVE-2021-47580
- Published
- Jun 19, 2024
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-787, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 19, 2024CVE publishedPublication date reported by the CVE source.
- Aug 5, 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=5.8
- Affected versionversion=87c715dcde633f4cc4690a24a240e838181e6a9d <3085147645938eb41f0bc0e25ef9791e71f5ee4b
- Affected versionversion=87c715dcde633f4cc4690a24a240e838181e6a9d <36e07d7ede88a1f1ef8f0f209af5b7612324ac2c
- Affected versionversion=87c715dcde633f4cc4690a24a240e838181e6a9d <bdb854f134b964528fa543e0351022eb45bd7346
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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Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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