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

Greg Kroah-Hartman
2021-12-27T15:36:03Z

From: Sumit Garg <sumit.garg@linaro.org>

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@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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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,