Bug 2482008 (CVE-2026-46023)

In the Linux kernel, the following vulnerability has been resolved:

dm mirror: fix integer overflow in create_dirty_log()

The argument count calculation in create_dirty_log() performs
`*args_used = 2 + param_count` before validating against argc. When a
user provides a param_count close to UINT_MAX via the device mapper
table string, this unsigned addition wraps around to a small value,
causing the subsequent `argc < *args_used` check to be bypassed.

The overflowed param_count is then passed as argc to dm_dirty_log_create(),
where it can cause out-of-bounds reads on the argv array.

Fix by comparing param_count against argc - 2 before performing the
addition, following the same pattern used by parse_features() in the
same file. Since argc >= 2 is already guaranteed, the subtraction is
safe.