[PATCH 5.4 35/47] tee: optee: Fix incorrect page free bug

[Greg Kroah-Hartman]

From: Sumit Garg <sumit.garg@xxxxxxxxxx>

commit 18549bf4b21c739a9def39f27dcac53e27286ab5 upstream.

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: ec185dd3ab25 ("optee: Fix memory leak when failing to register shm pages")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Patrik Lantz <patrik.lantz@xxxxxxxx>
Signed-off-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
Reviewed-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/tee/optee/shm_pool.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

--- a/drivers/tee/optee/shm_pool.c
+++ b/drivers/tee/optee/shm_pool.c
@@ -41,10 +41,8 @@ static int pool_op_alloc(struct tee_shm_
 			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 = optee_shm_register(shm->ctx, shm, pages, nr_pages,