CVE-2025-21874 is a vulnerability in the Linux kernel's dm-integrity module where a divide-by-zero error can occur in Inline mode when querying the device-mapper table status. This happens because the calculation of the journal watermark divides by journal_sectors, which is zero in Inline mode since the journal is unused. The flaw can cause a kernel crash (OOPS) when running a simple table query such as 'dmsetup table'.