Linux Kernel Vulnerability in ext4 Handling Symlink Inodes

CVE-2025-38220

What is CVE-2025-38220?

A vulnerability has been identified in the Linux kernel's ext4 filesystem affecting the handling of symlink inodes. When processing a symlink inode from the orphan list during a truncation operation, a NULL pointer dereference may occur due to improper management of dirty folios in data journaling for regular files. This flaw can lead to a system crash, evidenced by error messages indicating a kernel NULL pointer dereference. To rectify this issue, it's essential to update the ext4_dirty_journalled_data() helper to only mark dirty the folios of regular files where appropriate operations are assigned, thus aligning with existing journaling logic.

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