CVE-2026-64266

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

fuse: re-lock request before returning from fuse_ref_folio()

fuse_ref_folio() unlocks the request but does not re-lock it before returning. fuse_chan_abort() can end the request and the async end callback (eg fuse_writepage_free()) can free the args while the subsequent copy chain logic after fuse_ref_folio() accesses them, leading to use-after-free issues.

Fix this by locking the request in fuse_ref_folio() before returning.