CVE-2025-37858

Vulnerability Details

Basic Information

Title CVE-2025-37858
Type cve
Published 2025-05-09T07:16:06
Last Seen 2025-05-09T07:28:34
CVSS Score 0.0 ()

CVSS v3 Details

Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact

CVE Information

CVE IDs CVE-2025-37858
CWE
Bulletin Family cve

Description

In the Linux kernel, the following vulnerability has been resolved:

fs/jfs: Prevent integer overflow in AG size calculation

The JFS filesystem calculates allocation group (AG) size using 1 << l2agsize in dbExtendFS(). When l2agsize exceeds 31 (possible with >2TB
aggregates on 32-bit systems), this 32-bit shift operation causes undefined
behavior and improper AG sizing.

On 32-bit architectures:
– Left-shifting 1 by 32+ bits results in 0 due to integer overflow
– This creates invalid AG sizes (0 or garbage values) in
sbi->bmap->db_agsize
– Subsequent block allocations would reference invalid AG structures
– Could lead to:
– Filesystem corruption during extend operations
– Kernel crashes due to invalid memory accesses
– Security vulnerabilities via malformed on-disk structures

Fix by casting to s64 before shifting:
bmp->db_agsize = (s64)1 << l2agsize; This ensures 64-bit arithmetic even on 32-bit architectures. The cast matches the data type of db_agsize (s64) and follows similar patterns in JFS block calculation code. Found by Linux Verification Center (linuxtesting.org) with SVACE.

Impact Assessment

Base Score 0.0
Severity

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