drivers/media/platform/qcom/venus/helpers.c:627 venus_helper_get_bufreq() error: we previously assumed 'req' could be null (see line 623)

[Dan Carpenter]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   90c9e950c0def5c354b4a6154a2ddda3e5f214ac
commit: 16545aa3dee5a01f3f42aa566a051096c87f4b6f media: venus: Set buffer to FW based on FW min count requirement.
config: microblaze-randconfig-m031-20220206 (https://download.01.org/0day-ci/archive/20220206/202202062034.T1pUQtL9-lkp@xxxxxxxxx/config)
compiler: microblaze-linux-gcc (GCC) 11.2.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

smatch warnings:
drivers/media/platform/qcom/venus/helpers.c:627 venus_helper_get_bufreq() error: we previously assumed 'req' could be null (see line 623)

vim +/req +627 drivers/media/platform/qcom/venus/helpers.c

af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  615  int venus_helper_get_bufreq(struct venus_inst *inst, u32 type,
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  616  			    struct hfi_buffer_requirements *req)
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  617  {
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  618  	u32 ptype = HFI_PROPERTY_CONFIG_BUFFER_REQUIREMENTS;
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  619  	union hfi_get_property hprop;
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  620  	unsigned int i;
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  621  	int ret;
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  622  
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15 @623  	if (req)

Check for NULL

af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  624  		memset(req, 0, sizeof(*req));
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  625  
16545aa3dee5a01 Dikshita Agarwal  2021-08-10  626  	if (type == HFI_BUFFER_OUTPUT || type == HFI_BUFFER_OUTPUT2)
16545aa3dee5a01 Dikshita Agarwal  2021-08-10 @627  		req->count_min = inst->fw_min_cnt;

Unchecked dereference

16545aa3dee5a01 Dikshita Agarwal  2021-08-10  628  
7371093f983d35d Stanimir Varbanov 2020-08-26  629  	ret = platform_get_bufreq(inst, type, req);

I looked at this in linux-next from Friday and I don't think
platform_get_bufreq() can succeed with a NULL "req"...

16545aa3dee5a01 Dikshita Agarwal  2021-08-10  630  	if (!ret) {
16545aa3dee5a01 Dikshita Agarwal  2021-08-10  631  		if (type == HFI_BUFFER_OUTPUT || type == HFI_BUFFER_OUTPUT2)
16545aa3dee5a01 Dikshita Agarwal  2021-08-10  632  			inst->fw_min_cnt = req->count_min;

Unchecked

7371093f983d35d Stanimir Varbanov 2020-08-26  633  		return 0;
16545aa3dee5a01 Dikshita Agarwal  2021-08-10  634  	}
7371093f983d35d Stanimir Varbanov 2020-08-26  635  
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  636  	ret = hfi_session_get_property(inst, ptype, &hprop);
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  637  	if (ret)
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  638  		return ret;
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  639  
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  640  	ret = -EINVAL;
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  641  
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  642  	for (i = 0; i < HFI_BUFFER_TYPE_MAX; i++) {
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  643  		if (hprop.bufreq[i].type != type)
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  644  			continue;
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  645  
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  646  		if (req)
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  647  			memcpy(req, &hprop.bufreq[i], sizeof(*req));

Another NULL check

af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  648  		ret = 0;
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  649  		break;
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  650  	}
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  651  
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  652  	return ret;
af2c3834c8ca7cc Stanimir Varbanov 2017-06-15  653  }

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx