Linux Kernel F2FS Filesystem Denial-of-Service Vulnerability

A denial-of-service vulnerability has been identified in the Linux kernel's F2FS (Flash-Friendly File System) implementation. The issue arises when the system performs a sanity check on the segment information bitmap size. A specific sequence of commands can create a corrupted image with inconsistent metadata. When this image is mounted, it triggers a kernel panic by accessing out-of-bounds memory in the segment bitmap, causing a crash.

Impact

Exploiting this vulnerability leads to a kernel panic, causing a crash of the affected system.

Reproduction

The vulnerability can be reproduced by creating a large image file and formatting it with the F2FS filesystem. After resizing the filesystem, mounting the image will trigger the kernel panic. This sequence of actions can be automated with a script that executes the necessary commands.