The vulnerability stems from a mismatch between the inline data flag and the actual size of a file in the ext4 filesystem. If a file with the inline flag is truncated to a size beyond its inline capacity and then a write or sendfile operation is performed, the ext4_write_inline_data() function triggers a BUG_ON, causing a kernel crash. The reported issue occurs after the truncate() call inside ext4_setattr(). Based on the description, it is inferred that the failure only manifests when a subsequent write operation attempts to store data larger than the inline buffer.

The issue impacts any Linux kernel version that uses the ext4 filesystem and does not include the patch that converts inline data to extent-based storage during a truncate that exceeds the inline size. Because the CVE tracks only the Linux kernel, the vulnerability is vendor‑neutral within the Linux ecosystem. The affected versions are not listed in the CVE; it is inferred that any kernel lacking the commit added by the patch is potentially vulnerable.

The exploit requires local write access to the affected filesystem; a malicious user can invoke truncate() on a file with the inline flag set and then initiate a write or sendfile to trigger the crash. The EPSS score is < 1%, indicating a very low but nonzero exploitation probability. The vulnerability is not listed in CISA’s KEV catalog, which is inferred to mean that no publicly confirmed exploits exist at present. Based on these facts, the risk to a typical system is moderate, while the impact of a kernel panic is severe.