android_kernel_xiaomi_sm8350/drivers/tee/optee/shm_pool.c
Sumit Garg 806142c805 tee: optee: Fix incorrect page free bug
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>
2021-12-29 12:23:37 +01:00

100 lines
2.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2015, Linaro Limited
* Copyright (c) 2017, EPAM Systems
*/
#include <linux/device.h>
#include <linux/dma-buf.h>
#include <linux/genalloc.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
#include "optee_private.h"
#include "optee_smc.h"
#include "shm_pool.h"
static int pool_op_alloc(struct tee_shm_pool_mgr *poolm,
struct tee_shm *shm, size_t size)
{
unsigned int order = get_order(size);
struct page *page;
int rc = 0;
page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
if (!page)
return -ENOMEM;
shm->kaddr = page_address(page);
shm->paddr = page_to_phys(page);
shm->size = PAGE_SIZE << order;
/*
* Shared memory private to the OP-TEE driver doesn't need
* to be registered with OP-TEE.
*/
if (!(shm->flags & TEE_SHM_PRIV)) {
unsigned int nr_pages = 1 << order, i;
struct page **pages;
pages = kcalloc(nr_pages, sizeof(pages), GFP_KERNEL);
if (!pages) {
rc = -ENOMEM;
goto err;
}
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,
(unsigned long)shm->kaddr);
kfree(pages);
if (rc)
goto err;
}
return 0;
err:
__free_pages(page, order);
return rc;
}
static void pool_op_free(struct tee_shm_pool_mgr *poolm,
struct tee_shm *shm)
{
if (!(shm->flags & TEE_SHM_PRIV))
optee_shm_unregister(shm->ctx, shm);
free_pages((unsigned long)shm->kaddr, get_order(shm->size));
shm->kaddr = NULL;
}
static void pool_op_destroy_poolmgr(struct tee_shm_pool_mgr *poolm)
{
kfree(poolm);
}
static const struct tee_shm_pool_mgr_ops pool_ops = {
.alloc = pool_op_alloc,
.free = pool_op_free,
.destroy_poolmgr = pool_op_destroy_poolmgr,
};
/**
* optee_shm_pool_alloc_pages() - create page-based allocator pool
*
* This pool is used when OP-TEE supports dymanic SHM. In this case
* command buffers and such are allocated from kernel's own memory.
*/
struct tee_shm_pool_mgr *optee_shm_pool_alloc_pages(void)
{
struct tee_shm_pool_mgr *mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
if (!mgr)
return ERR_PTR(-ENOMEM);
mgr->ops = &pool_ops;
return mgr;
}