Host kernel panic via undersized IPI buffer
Published Sep 5, 2025 · Updated Aug 5, 2026
Buffer overflow in LoongArch KVM in Linux allows local users to crash the host kernel by triggering an undersized emulated IPI read. The send_ipi_data() function supplies a four-byte value to kvm_io_bus_read(), while loongarch_ipi_readl() and kvm_eiointc_read() unconditionally write eight sign-extended bytes into it. Exploitation requires a LoongArch KVM guest and a host kernel built with CONFIG_STACKPROTECTOR; the bounded outcome is a host kernel panic.
Summary
What happened
Buffer overflow in LoongArch KVM in Linux allows local users to crash the host kernel by triggering an undersized emulated IPI read. The send_ipi_data() function supplies a four-byte value to kvm_io_bus_read(), while loongarch_ipi_readl() and kvm_eiointc_read() unconditionally write eight sign-extended bytes into it. Exploitation requires a LoongArch KVM guest and a host kernel built with CONFIG_STACKPROTECTOR; the bounded outcome is a host kernel panic.
The record
- CVE
- CVE-2025-39704
- Published
- Sep 5, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-674, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 5, 2025CVE 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=6.13
- Affected versionversion=daee2f9cae5510ba1bd9eed6b0cf0ca8dc276118 <5c68549c81bcca70fc464e305ffeefd9af968287
- Affected versionversion=daee2f9cae5510ba1bd9eed6b0cf0ca8dc276118 <b5b49d341f90eed6de794b6ff34ad3dd66d34343
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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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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