CVE-2025-39877 mm/damon/sysfs: fix use-after-free in state_show()

In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs: fix use-after-free in stateshow stateshow reads kdamond-damonctx without holding damonsysfslock. This allows a use-after-free race: CPU 0 CPU 1 ----- ----- stateshow damonsysfsturndamonon ctx = kdamond-damonctx;...