CVE-2026-89640
Description
A flaw was found in the Linux kernel's Common Internet File System (CIFS) implementation. When performing a file range remapping operation with a zero length, an integer underflow can occur if the offset exceeds the file size. This can lead to corruption of the byte count in file system control requests, potentially causing unexpected behavior or data integrity issues. The vulnerability is resolved by correctly validating the offset against the file size before calculating the length, preventing the underflow.
Statement
Red Hat Product Security has determined that this vulnerability does not affect any currently supported Red Hat product. This assessment may evolve based on further analysis and discovery. For more information about this vulnerability and the products it affects, please see the linked references.
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
