Local denial of service via unmasked PCIe bits
Published Sep 11, 2025 · Updated Sep 11, 2025
Denial of service in the Linux kernel PCI subsystem 6.13 through 6.16.3 allows local users to trigger a kernel warning. When PCIe link retraining fails, pcie_failed_link_retrain() passes unmasked Link Control 2 bits through PCIE_LNKCTL2_TLS2SPEED(), producing PCI_SPEED_UNKNOWN for pcie_set_target_speed(). Exploitation requires local access and a failed PCIe link retrain; the resulting WARN splat disrupts kernel availability without reported data disclosure or modification.
Summary
What happened
Denial of service in the Linux kernel PCI subsystem 6.13 through 6.16.3 allows local users to trigger a kernel warning. When PCIe link retraining fails, pcie_failed_link_retrain() passes unmasked Link Control 2 bits through PCIE_LNKCTL2_TLS2SPEED(), producing PCI_SPEED_UNKNOWN for pcie_set_target_speed(). Exploitation requires local access and a failed PCIe link retrain; the resulting WARN splat disrupts kernel availability without reported data disclosure or modification.
The record
- CVE
- CVE-2025-39784
- Published
- Sep 11, 2025
- Updated
- Sep 11, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 11, 2025CVE publishedPublication date reported by the CVE source.
- Sep 11, 2025Record 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=6.13
- Affected versionversion=de9a6c8d5dbfedb5eb3722c822da0490f6a59a45 <16557320f378262b5c605b15edebd3642406992a
- Affected versionversion=de9a6c8d5dbfedb5eb3722c822da0490f6a59a45 <9989e0ca7462c62f93dbc62f684448aa2efb9226
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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Technologies
Your stack
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Your stack
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