diff mbox series

[v4] soc: qcom: mdt_loader: Add Upperbounds check for program header access

Message ID 20240213080010.16924-1-quic_audityab@quicinc.com (mailing list archive)
State Changes Requested
Headers show
Series [v4] soc: qcom: mdt_loader: Add Upperbounds check for program header access | expand

Commit Message

Auditya Bhattaram Feb. 13, 2024, 8 a.m. UTC 
hash_index is evaluated by looping phdrs till QCOM_MDT_TYPE_HASH
is found. Add an upperbound check to phdrs to access within elf size.

Fixes: 64fb5eb87d58 ("soc: qcom: mdt_loader: Allow hash to reside in any segment")
Cc: <stable@vger.kernel.org>
Signed-off-by: Auditya Bhattaram <quic_audityab@quicinc.com>
Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
---
Changes in v4:
 - Added additional prints incase of Invalid access.
Link to v3 https://lore.kernel.org/stable/1c91c653-cebe-4407-bdd6-cfc73b64c0fb@quicinc.com
Link to v2 https://lore.kernel.org/linux-arm-msm/9773d189-c896-d5c5-804c-e086c24987b4@quicinc.com/T/#t
Link to v1 https://lore.kernel.org/linux-arm-msm/5d7a3b97-d840-4863-91a0-32c1d8e7532f@linaro.org/T/#t
---
 drivers/soc/qcom/mdt_loader.c | 7 +++++++
 1 file changed, 7 insertions(+)

--
2.17.1

Comments

Bjorn Andersson Feb. 14, 2024, 5:42 a.m. UTC | #1 
On Tue, Feb 13, 2024 at 01:30:10PM +0530, Auditya Bhattaram wrote:
> hash_index is evaluated by looping phdrs till QCOM_MDT_TYPE_HASH
> is found. Add an upperbound check to phdrs to access within elf size.
> 

How is this compatible with what is being observed on SM8450 and
implemented in commit 8bd42e2341a7 ("soc: qcom: mdt_loader: Allow hash
segment to be split out"?

Regards,
Bjorn

> Fixes: 64fb5eb87d58 ("soc: qcom: mdt_loader: Allow hash to reside in any segment")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Auditya Bhattaram <quic_audityab@quicinc.com>
> Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
> ---
> Changes in v4:
>  - Added additional prints incase of Invalid access.
> Link to v3 https://lore.kernel.org/stable/1c91c653-cebe-4407-bdd6-cfc73b64c0fb@quicinc.com
> Link to v2 https://lore.kernel.org/linux-arm-msm/9773d189-c896-d5c5-804c-e086c24987b4@quicinc.com/T/#t
> Link to v1 https://lore.kernel.org/linux-arm-msm/5d7a3b97-d840-4863-91a0-32c1d8e7532f@linaro.org/T/#t
> ---
>  drivers/soc/qcom/mdt_loader.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c
> index 6f177e46fa0f..1a79a7bba468 100644
> --- a/drivers/soc/qcom/mdt_loader.c
> +++ b/drivers/soc/qcom/mdt_loader.c
> @@ -145,6 +143,13 @@ void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len,
>  	if (phdrs[0].p_type == PT_LOAD)
>  		return ERR_PTR(-EINVAL);
> 
> +	if (((size_t)(phdrs + ehdr->e_phnum)) > ((size_t)ehdr + fw->size)) {
> +		dev_err(dev,
> +			"Invalid phdrs access for fw: %s, e_phnum: %u, fw->size: %zu\n",
> +			fw_name, ehdr->e_phnum, fw->size);
> +		return ERR_PTR(-EINVAL);
> +	}
> +
>  	for (i = 1; i < ehdr->e_phnum; i++) {
>  		if ((phdrs[i].p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH) {
>  			hash_segment = i;
> --
> 2.17.1
>
Auditya Bhattaram Feb. 14, 2024, 5:57 a.m. UTC | #2 
On 2/14/2024 11:12 AM, Bjorn Andersson wrote:
> On Tue, Feb 13, 2024 at 01:30:10PM +0530, Auditya Bhattaram wrote:
>> hash_index is evaluated by looping phdrs till QCOM_MDT_TYPE_HASH
>> is found. Add an upperbound check to phdrs to access within elf size.
>>
> 
> How is this compatible with what is being observed on SM8450 and
> implemented in commit 8bd42e2341a7 ("soc: qcom: mdt_loader: Allow hash
> segment to be split out"?
> 
> Regards,
> Bjorn
> 

Calculating hash_index is introduced with this commit 8bd42e2341a7 
("soc: qcom: mdt_loader: Allow hash segment to be split out"

     for (i = 1; i < ehdr->e_phnum; i++) {
  	if ((phdrs[i].p_flags & QCOM_MDT_TYPE_MASK) ...

I'm trying to add an upper bound for this access "phdrs[i]"

>> Fixes: 64fb5eb87d58 ("soc: qcom: mdt_loader: Allow hash to reside in any segment")
>> Cc: <stable@vger.kernel.org>
>> Signed-off-by: Auditya Bhattaram <quic_audityab@quicinc.com>
>> Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
>> ---
>> Changes in v4:
>>   - Added additional prints incase of Invalid access.
>> Link to v3 https://lore.kernel.org/stable/1c91c653-cebe-4407-bdd6-cfc73b64c0fb@quicinc.com
>> Link to v2 https://lore.kernel.org/linux-arm-msm/9773d189-c896-d5c5-804c-e086c24987b4@quicinc.com/T/#t
>> Link to v1 https://lore.kernel.org/linux-arm-msm/5d7a3b97-d840-4863-91a0-32c1d8e7532f@linaro.org/T/#t
>> ---
>>   drivers/soc/qcom/mdt_loader.c | 7 +++++++
>>   1 file changed, 7 insertions(+)
>>
>> diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c
>> index 6f177e46fa0f..1a79a7bba468 100644
>> --- a/drivers/soc/qcom/mdt_loader.c
>> +++ b/drivers/soc/qcom/mdt_loader.c
>> @@ -145,6 +143,13 @@ void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len,
>>   	if (phdrs[0].p_type == PT_LOAD)
>>   		return ERR_PTR(-EINVAL);
>>
>> +	if (((size_t)(phdrs + ehdr->e_phnum)) > ((size_t)ehdr + fw->size)) {
>> +		dev_err(dev,
>> +			"Invalid phdrs access for fw: %s, e_phnum: %u, fw->size: %zu\n",
>> +			fw_name, ehdr->e_phnum, fw->size);
>> +		return ERR_PTR(-EINVAL);
>> +	}
>> +
>>   	for (i = 1; i < ehdr->e_phnum; i++) {
>>   		if ((phdrs[i].p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH) {
>>   			hash_segment = i;
>> --
>> 2.17.1
>>
Auditya Bhattaram March 12, 2024, 7:05 a.m. UTC | #3 
On 2/14/2024 11:27 AM, Auditya Bhattaram wrote:
> 
> 
> On 2/14/2024 11:12 AM, Bjorn Andersson wrote:
>> On Tue, Feb 13, 2024 at 01:30:10PM +0530, Auditya Bhattaram wrote:
>>> hash_index is evaluated by looping phdrs till QCOM_MDT_TYPE_HASH
>>> is found. Add an upperbound check to phdrs to access within elf size.
>>>
>>
>> How is this compatible with what is being observed on SM8450 and
>> implemented in commit 8bd42e2341a7 ("soc: qcom: mdt_loader: Allow hash
>> segment to be split out"?
>>
>> Regards,
>> Bjorn
>>
> 
> Calculating hash_index is introduced with this commit 8bd42e2341a7 
> ("soc: qcom: mdt_loader: Allow hash segment to be split out"
> 
>      for (i = 1; i < ehdr->e_phnum; i++) {
>       if ((phdrs[i].p_flags & QCOM_MDT_TYPE_MASK) ...
> 
> I'm trying to add an upper bound for this access "phdrs[i]"
> 

Any further questions on this Bjorn.

>>> Fixes: 64fb5eb87d58 ("soc: qcom: mdt_loader: Allow hash to reside in 
>>> any segment")
>>> Cc: <stable@vger.kernel.org>
>>> Signed-off-by: Auditya Bhattaram <quic_audityab@quicinc.com>
>>> Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
>>> ---
>>> Changes in v4:
>>>   - Added additional prints incase of Invalid access.
>>> Link to v3 
>>> https://lore.kernel.org/stable/1c91c653-cebe-4407-bdd6-cfc73b64c0fb@quicinc.com
>>> Link to v2 
>>> https://lore.kernel.org/linux-arm-msm/9773d189-c896-d5c5-804c-e086c24987b4@quicinc.com/T/#t
>>> Link to v1 
>>> https://lore.kernel.org/linux-arm-msm/5d7a3b97-d840-4863-91a0-32c1d8e7532f@linaro.org/T/#t
>>> ---
>>>   drivers/soc/qcom/mdt_loader.c | 7 +++++++
>>>   1 file changed, 7 insertions(+)
>>>
>>> diff --git a/drivers/soc/qcom/mdt_loader.c 
>>> b/drivers/soc/qcom/mdt_loader.c
>>> index 6f177e46fa0f..1a79a7bba468 100644
>>> --- a/drivers/soc/qcom/mdt_loader.c
>>> +++ b/drivers/soc/qcom/mdt_loader.c
>>> @@ -145,6 +143,13 @@ void *qcom_mdt_read_metadata(const struct 
>>> firmware *fw, size_t *data_len,
>>>       if (phdrs[0].p_type == PT_LOAD)
>>>           return ERR_PTR(-EINVAL);
>>>
>>> +    if (((size_t)(phdrs + ehdr->e_phnum)) > ((size_t)ehdr + 
>>> fw->size)) {
>>> +        dev_err(dev,
>>> +            "Invalid phdrs access for fw: %s, e_phnum: %u, fw->size: 
>>> %zu\n",
>>> +            fw_name, ehdr->e_phnum, fw->size);
>>> +        return ERR_PTR(-EINVAL);
>>> +    }
>>> +
>>>       for (i = 1; i < ehdr->e_phnum; i++) {
>>>           if ((phdrs[i].p_flags & QCOM_MDT_TYPE_MASK) == 
>>> QCOM_MDT_TYPE_HASH) {
>>>               hash_segment = i;
>>> -- 
>>> 2.17.1
>>>
Bjorn Andersson March 16, 2024, 5:17 p.m. UTC | #4 
On Wed, Feb 14, 2024 at 11:27:01AM +0530, Auditya Bhattaram wrote:
> 
> 
> On 2/14/2024 11:12 AM, Bjorn Andersson wrote:
> > On Tue, Feb 13, 2024 at 01:30:10PM +0530, Auditya Bhattaram wrote:
> > > hash_index is evaluated by looping phdrs till QCOM_MDT_TYPE_HASH
> > > is found. Add an upperbound check to phdrs to access within elf size.
> > > 
> > 
> > How is this compatible with what is being observed on SM8450 and
> > implemented in commit 8bd42e2341a7 ("soc: qcom: mdt_loader: Allow hash
> > segment to be split out"?
> > 
> > Regards,
> > Bjorn
> > 
> 
> Calculating hash_index is introduced with this commit 8bd42e2341a7 ("soc:
> qcom: mdt_loader: Allow hash segment to be split out"
> 
>     for (i = 1; i < ehdr->e_phnum; i++) {
>  	if ((phdrs[i].p_flags & QCOM_MDT_TYPE_MASK) ...
> 
> I'm trying to add an upper bound for this access "phdrs[i]"
> 

Ahh, sorry, you're of course correct. I think I would have preferred a
more obvious check of offset >= fw->size though...

That said, this code used to sit behind rproc_elf_sanity_check(), but
that seem to have been lost in the refactorings. As such, your patch is
incomplete and we should reintroduce a whole bunch of these sanity
checks!

Regards,
Bjorn

> > > Fixes: 64fb5eb87d58 ("soc: qcom: mdt_loader: Allow hash to reside in any segment")
> > > Cc: <stable@vger.kernel.org>
> > > Signed-off-by: Auditya Bhattaram <quic_audityab@quicinc.com>
> > > Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
> > > ---
> > > Changes in v4:
> > >   - Added additional prints incase of Invalid access.
> > > Link to v3 https://lore.kernel.org/stable/1c91c653-cebe-4407-bdd6-cfc73b64c0fb@quicinc.com
> > > Link to v2 https://lore.kernel.org/linux-arm-msm/9773d189-c896-d5c5-804c-e086c24987b4@quicinc.com/T/#t
> > > Link to v1 https://lore.kernel.org/linux-arm-msm/5d7a3b97-d840-4863-91a0-32c1d8e7532f@linaro.org/T/#t
> > > ---
> > >   drivers/soc/qcom/mdt_loader.c | 7 +++++++
> > >   1 file changed, 7 insertions(+)
> > > 
> > > diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c
> > > index 6f177e46fa0f..1a79a7bba468 100644
> > > --- a/drivers/soc/qcom/mdt_loader.c
> > > +++ b/drivers/soc/qcom/mdt_loader.c
> > > @@ -145,6 +143,13 @@ void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len,
> > >   	if (phdrs[0].p_type == PT_LOAD)
> > >   		return ERR_PTR(-EINVAL);
> > > 
> > > +	if (((size_t)(phdrs + ehdr->e_phnum)) > ((size_t)ehdr + fw->size)) {
> > > +		dev_err(dev,
> > > +			"Invalid phdrs access for fw: %s, e_phnum: %u, fw->size: %zu\n",
> > > +			fw_name, ehdr->e_phnum, fw->size);
> > > +		return ERR_PTR(-EINVAL);
> > > +	}
> > > +
> > >   	for (i = 1; i < ehdr->e_phnum; i++) {
> > >   		if ((phdrs[i].p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH) {
> > >   			hash_segment = i;
> > > --
> > > 2.17.1
> > >
diff mbox series

Patch

diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c
index 6f177e46fa0f..1a79a7bba468 100644
--- a/drivers/soc/qcom/mdt_loader.c
+++ b/drivers/soc/qcom/mdt_loader.c
@@ -145,6 +143,13 @@  void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len,
 	if (phdrs[0].p_type == PT_LOAD)
 		return ERR_PTR(-EINVAL);

+	if (((size_t)(phdrs + ehdr->e_phnum)) > ((size_t)ehdr + fw->size)) {
+		dev_err(dev,
+			"Invalid phdrs access for fw: %s, e_phnum: %u, fw->size: %zu\n",
+			fw_name, ehdr->e_phnum, fw->size);
+		return ERR_PTR(-EINVAL);
+	}
+
 	for (i = 1; i < ehdr->e_phnum; i++) {
 		if ((phdrs[i].p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH) {
 			hash_segment = i;