From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Patrik Lantz <patrik.lantz@axis.com>,
        Sumit Garg <sumit.garg@linaro.org>,
        Tyler Hicks <tyhicks@linux.microsoft.com>,
        Jens Wiklander <jens.wiklander@linaro.org>
Subject: [PATCH 5.4 35/47] tee: optee: Fix incorrect page free bug
Date:   Mon, 27 Dec 2021 16:31:11 +0100
Message-Id: <20211227151322.004889674@linuxfoundation.org>
In-Reply-To: <20211227151320.801714429@linuxfoundation.org>
References: <20211227151320.801714429@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

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,