CVE-2026-53015
Received Received - Intake
Integer Overflow in EROFS Linux Kernel Filesystem

Publication date: 2026-06-24

Last updated on: 2026-06-24

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: erofs: unify lcn as u64 for 32-bit platforms As sashiko reported [1], `lcn` was typed as `unsigned long` (or `unsigned int` sometimes), which is only 32 bits wide on 32-bit platforms, which causes `(lcn << lclusterbits)` to be truncated at 4 GiB. In order to consolidate the logic, just use `u64` consistently around the codebase. [1] https://sashiko.dev/r/20260420034612.1899973-1-hsiangkao%40linux.alibaba.com
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Meta Information
Published
2026-06-24
Last Modified
2026-06-24
Generated
2026-06-25
AI Q&A
2026-06-24
EPSS Evaluated
N/A
NVD
CVE-2026-53015
EUVD
EUVD-2026-38883
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
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Exploitability
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

This vulnerability exists in the Linux kernel's erofs filesystem code where the variable 'lcn' was defined as 'unsigned long' or sometimes 'unsigned int'. On 32-bit platforms, these types are only 32 bits wide, which causes the calculation '(lcn << lclusterbits)' to be truncated at 4 GiB.

The issue was that the truncation could lead to incorrect behavior when handling large files or data beyond 4 GiB. The fix was to unify the 'lcn' type as a 64-bit unsigned integer (u64) consistently throughout the codebase to prevent this truncation.

Impact Analysis

Because the 'lcn' value was truncated on 32-bit platforms, this could cause incorrect file system behavior when dealing with files or data larger than 4 GiB. This might lead to data corruption, incorrect file access, or system instability when using the erofs filesystem on affected systems.

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