CVE-2025-21860

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/zswap: fix inconsistency when zswap_store_page() fails<br /> <br /> Commit b7c0ccdfbafd ("mm: zswap: support large folios in zswap_store()")<br /> skips charging any zswap entries when it failed to zswap the entire folio.<br /> <br /> However, when some base pages are zswapped but it failed to zswap the<br /> entire folio, the zswap operation is rolled back. When freeing zswap<br /> entries for those pages, zswap_entry_free() uncharges the zswap entries<br /> that were not previously charged, causing zswap charging to become<br /> inconsistent.<br /> <br /> This inconsistency triggers two warnings with following steps:<br /> # On a machine with 64GiB of RAM and 36GiB of zswap<br /> $ stress-ng --bigheap 2 # wait until the OOM-killer kills stress-ng<br /> $ sudo reboot<br /> <br /> The two warnings are:<br /> in mm/memcontrol.c:163, function obj_cgroup_release():<br /> WARN_ON_ONCE(nr_bytes &amp; (PAGE_SIZE - 1));<br /> <br /> in mm/page_counter.c:60, function page_counter_cancel():<br /> if (WARN_ONCE(new