In the Linux kernel, the following vulnerability has been resolved: arm64: mte: Do not warn if the page is already tagged in copyhighpage() The arm64 copyhighpage() assumes that the destination page is newly allocated and not MTE-tagged (PGmtetagged unset) and warns accordingly. However, following commit 060913999d7a ("mm: migrate: support poisoned recover from migrate folio"), foliomccopy() is called before _foliomigratemapping(). If the latter fails (-EAGAIN), the copy will be done again to the same destination page. Since copyhighpage() already set the PGmtetagged flag, this second copy will warn. Replace the WARNONONCE(page already tagged) in the arm64 copy_highpage() with a comment.