CVE-2021-47637

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A deadlock issue in the Linux kernel has been identified, specifically in the ubifs file system. This occurs when concurrent rename whiteout and inode writeback processes are executed, causing tasks to hang. The issue arises from the locking mechanism used by the ubifs rename and ubifs write inode functions, which can lead to a deadlock situation. The problem is triggered by the SYS renameat2 system call when used with the RENAME WHITEOUT flag, and it can be reproduced by consuming available space before the kernel performs budgeting for the whiteout operation.

Recommendations To resolve this issue, apply the fix that budgets whiteout space before locking ubifs inodes. This fix also corrects an error handling path in the whiteout budget, ensuring proper recovery of directory i size and unlocking of ubifs inodes. At the moment, there is no information about a newer version that contains a fix for this vulnerability.