CVE-2026-64053
Received Received - Intake

Linux Kernel Block Layer Integrity Bypass

Publication date: 2026-07-19

Last updated on: 2026-07-19

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: block: don't overwrite bip_vcnt in bio_integrity_copy_user() bio_integrity_add_page() already sets bip_vcnt to 1 for the bounce segment. Overwriting it with nr_vecs breaks bip_vcnt <= bip_max_vcnt on WRITE (bip_max_vcnt is 1), so the gap-merge checks in block/blk.h read past the bip_vec[] flex array. On READ the read is in bounds but lands on a saved user bvec instead of the bounce. The line was added for split propagation, but bio_integrity_clone() doesn't copy bip_vcnt and BIP_CLONE_FLAGS excludes BIP_COPY_USER.

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Meta Information

Published
2026-07-19
Last Modified
2026-07-19
Generated
2026-07-20
AI Q&A
2026-07-19
EPSS Evaluated
N/A
NVD
CVE-2026-64053
EUVD
EUVD-2026-45626

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

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Exploitability

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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves a flaw in the block layer's integrity handling. When copying user data, the bip_vcnt value in the bio integrity structure is incorrectly overwritten, leading to potential out-of-bounds memory access during read or write operations.

Detection Guidance

This vulnerability is specific to the Linux kernel's block integrity subsystem and requires kernel-level inspection. Detection involves checking kernel logs for integrity-related errors or crashes. Use commands like dmesg | grep -i integrity or journalctl -k | grep -i integrity to search for related errors. If the system uses integrity features (e.g., dm-integrity), verify kernel versions and configurations.

Impact Analysis

This vulnerability could allow an attacker to cause a system crash, corrupt data, or potentially execute arbitrary code with kernel privileges. It affects systems using the Linux kernel with block device integrity features enabled.

Compliance Impact

This vulnerability affects data integrity in the Linux kernel's block layer, specifically when handling integrity-protected I/O operations. While it does not directly impact compliance with standards like GDPR or HIPAA, it could lead to data corruption or unauthorized access if exploited, potentially violating integrity requirements under these regulations.

Mitigation Strategies

Apply the latest kernel update from your distribution to patch this issue. If immediate patching is not possible, disable block integrity features if not required by unloading related modules (e.g., dm-integrity) or adjusting kernel parameters. Monitor kernel logs for integrity-related errors post-update.

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