tee: optee: Fix incorrect page free bug

Bugzilla: https://bugzilla.redhat.com/2166659

commit 18549bf
Author: Sumit Garg <sumit.garg@linaro.org>
Date:   Thu Dec 16 11:17:25 2021 +0530

    tee: optee: Fix incorrect page free bug

    Pointer to the allocated pages (struct page *page) has already
    progressed towards the end of allocation. It is incorrect to perform
    __free_pages(page, order) using this pointer as we would free any
    arbitrary pages. Fix this by stop modifying the page pointer.

    Fixes: ec185dd ("optee: Fix memory leak when failing to register shm pages")
    Cc: stable@vger.kernel.org
    Reported-by: Patrik Lantz <patrik.lantz@axis.com>
    Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
    Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
    Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>

Author: Chris von Recklinghausen

drivers/tee/optee/core.c

@@ -48,10 +48,8 @@ int optee_pool_op_alloc_helper(struct tee_shm_pool_mgr *poolm,
 			goto err;
 		}
 
-		for (i = 0; i < nr_pages; i++) {
-			pages[i] = page;
-			page++;
-		}
+		for (i = 0; i < nr_pages; i++)
+			pages[i] = page + i;
 
 		shm->flags |= TEE_SHM_REGISTER;
 		rc = shm_register(shm->ctx, shm, pages, nr_pages,