diff --git a/mm/memory.c b/mm/memory.c
index 5392bcb1d24d..ae8d567bc6ba 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3761,6 +3761,13 @@ static inline int __wp_page_copy_user(struct page *dst, struct page *src,
 		return 0;
 	}
 
+	/*
+	 * __copy_from_user_inatomic() only works as expected for local faults.
+	 * Reject remote faults.
+	 */
+	if (unlikely(mm != current->mm))
+		return -EFAULT;
+
 	/*
 	 * If the source page was a PFN mapping, we don't have
 	 * a "struct page" for it. We do a best-effort copy by
@@ -4086,6 +4093,8 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
 				folio_put(old_folio);
 
 			delayacct_wpcopy_end();
+			if (err == -EFAULT)
+				return VM_FAULT_SIGBUS;
 			return err == -EHWPOISON ? VM_FAULT_HWPOISON : 0;
 		}
 		kmsan_copy_page_meta(&new_folio->page, vmf->page);