CVE-2024-41033

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

cachestat: do not flush stats in recency check

syzbot detects that cachestat() is flushing stats, which can sleep, in its RCU read section (see [1]). This is done in the workingsettestrecent() step (which checks if the folio's eviction is recent).

Move the stat flushing step to before the RCU read section of cachestat, and skip stat flushing during the recency check.