In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Fix off-by-one in port I/O handling handle_in() and handle_out() in… (CVE-2026-89751)
A vulnerability in the Linux kernel's x86/tdx port I/O handling was fixed. The issue was an off-by-one error in the mask calculation used in handle_in() and handle_out() functions, causing the mask to be one bit too wide for all I/O sizes. This was corrected to ensure the mask accurately reflects the intended bit width.
AI Analysis
Technical Summary
The Linux kernel had an off-by-one vulnerability in the x86/tdx port I/O handling code within handle_in() and handle_out() functions. The mask calculation used GENMASK(BITS_PER_BYTE * size, 0), which incorrectly included an extra bit when size=1, producing a 9-bit mask instead of the correct 8-bit mask. This error could affect the correctness of port I/O operations. The vulnerability has been resolved by fixing the mask calculation to correctly limit the mask to the intended bit width.
Potential Impact
The vulnerability could cause incorrect masking in port I/O operations on x86/tdx, potentially leading to improper handling of I/O data. No specific exploitation details or impacts such as privilege escalation or denial of service are provided in the available data.
Mitigation Recommendations
A fix is available as the vulnerability has been resolved in the Linux kernel source code. Users should apply the official kernel updates that include the corrected mask calculation in the x86/tdx port I/O handling code. No additional mitigation guidance is provided.
In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Fix off-by-one in port I/O handling handle_in() and handle_out() in… (CVE-2026-89751)
Description
A vulnerability in the Linux kernel's x86/tdx port I/O handling was fixed. The issue was an off-by-one error in the mask calculation used in handle_in() and handle_out() functions, causing the mask to be one bit too wide for all I/O sizes. This was corrected to ensure the mask accurately reflects the intended bit width.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel had an off-by-one vulnerability in the x86/tdx port I/O handling code within handle_in() and handle_out() functions. The mask calculation used GENMASK(BITS_PER_BYTE * size, 0), which incorrectly included an extra bit when size=1, producing a 9-bit mask instead of the correct 8-bit mask. This error could affect the correctness of port I/O operations. The vulnerability has been resolved by fixing the mask calculation to correctly limit the mask to the intended bit width.
Potential Impact
The vulnerability could cause incorrect masking in port I/O operations on x86/tdx, potentially leading to improper handling of I/O data. No specific exploitation details or impacts such as privilege escalation or denial of service are provided in the available data.
Mitigation Recommendations
A fix is available as the vulnerability has been resolved in the Linux kernel source code. Users should apply the official kernel updates that include the corrected mask calculation in the x86/tdx port I/O handling code. No additional mitigation guidance is provided.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-pv9x-wp8q-3x5j
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-89751"]
Threat ID: 6aa49ff655bf5e2cf5a865aa
Added to database: 09/12/2026, 00:42:30 UTC
Last enriched: 09/12/2026, 00:47:04 UTC
Last updated: 09/12/2026, 00:47:04 UTC
Views: 1
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