From: Peter Collingbourne pcc@google.com
commit 6dca4ac6fc91fd41ea4d6c4511838d37f4e0eab2 upstream.
Commit c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") moved the call to swap_free() before the call to set_pte_at(), which meant that the MTE tags could end up being freed before set_pte_at() had a chance to restore them. Fix it by adding a call to the arch_swap_restore() hook before the call to swap_free().
Link: https://lkml.kernel.org/r/20230523004312.1807357-2-pcc@google.com Link: https://linux-review.googlesource.com/id/I6470efa669e8bd2f841049b8c61020c510... Fixes: c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") Signed-off-by: Peter Collingbourne pcc@google.com Reported-by: Qun-wei Lin Qun-wei.Lin@mediatek.com Closes: https://lore.kernel.org/all/5050805753ac469e8d727c797c2218a9d780d434.camel@m... Acked-by: David Hildenbrand david@redhat.com Acked-by: "Huang, Ying" ying.huang@intel.com Reviewed-by: Steven Price steven.price@arm.com Acked-by: Catalin Marinas catalin.marinas@arm.com Cc: stable@vger.kernel.org [6.1+] Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/memory.c | 7 +++++++ 1 file changed, 7 insertions(+)
--- a/mm/memory.c +++ b/mm/memory.c @@ -3915,6 +3915,13 @@ vm_fault_t do_swap_page(struct vm_fault }
/* + * Some architectures may have to restore extra metadata to the page + * when reading from swap. This metadata may be indexed by swap entry + * so this must be called before swap_free(). + */ + arch_swap_restore(entry, folio); + + /* * Remove the swap entry and conditionally try to free up the swapcache. * We're already holding a reference on the page but haven't mapped it * yet.