CVE-2024-26832

In the Linux kernel, the following vulnerability has been resolved: mm:
zswap: fix missing folio cleanup in writeback race path In
zswap_writeback_entry(), after we get a folio from
__read_swap_cache_async(), we grab the tree lock again to check that the
swap entry was not invalidated and recycled. If it was, we delete the folio
we just added to the swap cache and exit. However,
__read_swap_cache_async() returns the folio locked when it is newly
allocated, which is always true for this path, and the folio is ref’d. Make
sure to unlock and put the folio before returning. This was discovered by
code inspection, probably because this path handles a race condition that
should not happen often, and the bug would not crash the system, it will
only strand the folio indefinitely.

Bugs

• <https://bugzilla.redhat.com/show_bug.cgi?id=2275590&gt;
• <https://bugzilla.suse.com/show_bug.cgi?id=1223007&gt;

Notes