Host hang via unbalanced PCI resume locking
Published May 21, 2024 · Updated Aug 5, 2026
Improper locking in Linux 5.10 through 5.10.240, 5.11 through 5.14.11, and 5.15-rc1 through 5.15-rc4 allows local users to hang the host. When normal-channel PCI recovery reaches amdgpu_pci_resume, the callback releases the amdgpu reset write lock without first acquiring it, deadlocking later readers. The path requires local AMD GPU access and a PCIe error-recovery event; the resulting lock imbalance interrupts the host rather than exposing a network service.
Summary
What happened
Improper locking in Linux 5.10 through 5.10.240, 5.11 through 5.14.11, and 5.15-rc1 through 5.15-rc4 allows local users to hang the host. When normal-channel PCI recovery reaches amdgpu_pci_resume, the callback releases the amdgpu reset write lock without first acquiring it, deadlocking later readers. The path requires local AMD GPU access and a PCIe error-recovery event; the resulting lock imbalance interrupts the host rather than exposing a network service.
The record
- CVE
- CVE-2021-47421
- Published
- May 21, 2024
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-667, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 21, 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=5.10
- Affected versionversion=c9a6b82f45e261d247b980a7949aaa6a9bfffe01 <248b061689a40f4fed05252ee2c89f87cf26d7d8
- Affected versionversion=c9a6b82f45e261d247b980a7949aaa6a9bfffe01 <72e9a1bf9b722628c28092e0c2cd8717edd201dc
- Affected versionversion=c9a6b82f45e261d247b980a7949aaa6a9bfffe01 <785cc093b6b5a93cc350421a55f3f1eda6585156
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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