linux-kernel - Re: [PATCH v2 2/2] firmware: qcom: qcom

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <5e52d6c5-6e42-4244-bf66-a2d1343ad868@quicinc.com>
Date: Wed, 23 Oct 2024 00:03:57 +0530
From: Kuldeep Singh <quic_kuldsing@...cinc.com>
To: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
CC: Bartosz Golaszewski <brgl@...ev.pl>,
        Bjorn Andersson
	<andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>,
        <linux-arm-msm@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 2/2] firmware: qcom: qcom_tzmem: Implement sanity
 checks



On 10/22/2024 12:27 PM, Bartosz Golaszewski wrote:
> On Tue, 22 Oct 2024 at 07:43, Kuldeep Singh <quic_kuldsing@...cinc.com> wrote:
>>
>>
>>
>> On 10/16/2024 2:31 PM, Kuldeep Singh wrote:
>>>
>>> On 10/14/2024 6:38 PM, Bartosz Golaszewski wrote:
>>>> On Mon, Oct 14, 2024 at 1:19 PM Kuldeep Singh <quic_kuldsing@...cinc.com> wrote:
>>>>>
>>>>> The qcom_tzmem driver currently has exposed APIs that lack validations
>>>>> on required input parameters. This oversight can lead to unexpected null
>>>>> pointer dereference crashes.
>>>>>
>>>>
>>>> The commit message is not true. None of the things you changed below
>>>> can lead to a NULL-pointer dereference.>
>>>>> To address this issue, add sanity for required input parameters.
>>>>>
>>>>> Signed-off-by: Kuldeep Singh <quic_kuldsing@...cinc.com>
>>>>> ---
>>>>>  drivers/firmware/qcom/qcom_tzmem.c | 6 ++++++
>>>>>  1 file changed, 6 insertions(+)
>>>>>
>>>>> diff --git a/drivers/firmware/qcom/qcom_tzmem.c b/drivers/firmware/qcom/qcom_tzmem.c
>>>>> index 92b365178235..977e48fec32f 100644
>>>>> --- a/drivers/firmware/qcom/qcom_tzmem.c
>>>>> +++ b/drivers/firmware/qcom/qcom_tzmem.c
>>>>> @@ -203,6 +203,9 @@ qcom_tzmem_pool_new(const struct qcom_tzmem_pool_config *config)
>>>>>
>>>>>         might_sleep();
>>>>>
>>>>> +       if (!config->policy)
>>>>> +               return ERR_PTR(-EINVAL);
>>>>
>>>> This is already handled by the default case of the switch.
>>>
>>> Ack. Need to drop.
>>> https://elixir.bootlin.com/linux/v6.12-rc3/source/drivers/firmware/qcom/qcom_tzmem.c#L218
>>>
>>> While examining qcom_tzmem_pool_free under the same principle, it
>>> appears the following check is unnecessary.
>>> https://elixir.bootlin.com/linux/v6.12-rc3/source/drivers/firmware/qcom/qcom_tzmem.c#L268
>>>
>>
>> Bartosz,
>> I am thinking to remove below check in next rev like mentioned above.
>> https://elixir.bootlin.com/linux/v6.12-rc3/source/drivers/firmware/qcom/qcom_tzmem.c#L268
>>
>> Do you have any other opinion here?
>> Please let me know.
>>
> 
> No, let's keep the NULL-pointer check and add it to qcom_tzmem_free(),
> I'm not against it. I was just saying that in the latter case it will
> already be handled by the radix tree lookup.

Hey, I think you misread my comment. Let me explain more.
As agreed, Will drop (!config->policy) check from qcom_tzmem_pool_new
because it's already present.
https://elixir.bootlin.com/linux/v6.12-rc3/source/drivers/firmware/qcom/qcom_tzmem.c#L218

Keep (!vaddr) check in qcom_tzmem_free as discussed above.
https://elixir.bootlin.com/linux/v6.12-rc3/source/drivers/firmware/qcom/qcom_tzmem.c#L411

And last thing, like we don't check (!pool) in qcom_tzmem_alloc as it
cannot be null, same way I believe (!pool) is unnecessary in
qcom_tzmem_pool_free as qcom_tzmem_pool_new should return valid pool and
if not, should be handled by calling driver.
https://elixir.bootlin.com/linux/v6.12-rc3/source/drivers/firmware/qcom/qcom_tzmem.c#L369
https://elixir.bootlin.com/linux/v6.12-rc3/source/drivers/firmware/qcom/qcom_tzmem.c#L268

-- 
Regards
Kuldeep