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.