CVE-2025-40287
BaseFortify
Publication date: 2025-12-06
Last updated on: 2025-12-08
Assigner: kernel.org
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | kernel | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is an infinite loop bug in the exFAT file system of the Linux kernel. It occurs because the size validation code does not check if dentry.stream.valid_size is negative. When a malformed dentry with a negative valid_size is processed, certain system calls (SYS_openat, SYS_ftruncate, SYS_pwrite64) can cause the kernel to hang, leading to a Denial-of-Service (DoS) condition. The issue is fixed by adding a check to prevent negative valid_size values.
How can this vulnerability impact me? :
This vulnerability can cause the Linux kernel to hang when handling malformed exFAT file system entries, resulting in a Denial-of-Service (DoS) condition. This means that affected systems may become unresponsive or stop functioning properly when processing certain file operations on exFAT filesystems.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, update your Linux kernel to a version that includes the patch fixing the improper check of dentry.stream.valid_size in the exFAT filesystem. This patch prevents the infinite loop and Denial-of-Service condition caused by malformed dentries. Until the update is applied, avoid using SYS_openat, SYS_ftruncate, and SYS_pwrite64 system calls on exFAT filesystems with potentially untrusted or malformed files.