2021-06-01 18:48:08

by Gustavo A. R. Silva

[permalink] [raw]
Subject: [PATCH][venus-for-next-v5.14] media: venus: hfi_cmds: Fix packet size calculation

Now that a one-element array was replaced with a flexible-array member
in struct hfi_sys_set_property_pkt, use the struct_size() helper to
correctly calculate the packet size.

Fixes: 701e10b3fd9f ("media: venus: hfi_cmds.h: Replace one-element array with flexible-array member")
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
BTW... it seems that a similar problem is present in
https://lore.kernel.org/linux-hardening/20210211001044.GA69612@embeddedor/
and that is what is causing the regression. I will send v2 of that
patch, shortly. Thanks.

drivers/media/platform/qcom/venus/hfi_cmds.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/platform/qcom/venus/hfi_cmds.c b/drivers/media/platform/qcom/venus/hfi_cmds.c
index 11a8347e5f5c..c86279e5d6e8 100644
--- a/drivers/media/platform/qcom/venus/hfi_cmds.c
+++ b/drivers/media/platform/qcom/venus/hfi_cmds.c
@@ -27,7 +27,7 @@ void pkt_sys_idle_indicator(struct hfi_sys_set_property_pkt *pkt, u32 enable)
{
struct hfi_enable *hfi = (struct hfi_enable *)&pkt->data[1];

- pkt->hdr.size = sizeof(*pkt) + sizeof(*hfi) + sizeof(u32);
+ pkt->hdr.size = struct_size(pkt, data, 2) + sizeof(*hfi);
pkt->hdr.pkt_type = HFI_CMD_SYS_SET_PROPERTY;
pkt->num_properties = 1;
pkt->data[0] = HFI_PROPERTY_SYS_IDLE_INDICATOR;
@@ -39,7 +39,7 @@ void pkt_sys_debug_config(struct hfi_sys_set_property_pkt *pkt, u32 mode,
{
struct hfi_debug_config *hfi;

- pkt->hdr.size = sizeof(*pkt) + sizeof(*hfi) + sizeof(u32);
+ pkt->hdr.size = struct_size(pkt, data, 2) + sizeof(*hfi);
pkt->hdr.pkt_type = HFI_CMD_SYS_SET_PROPERTY;
pkt->num_properties = 1;
pkt->data[0] = HFI_PROPERTY_SYS_DEBUG_CONFIG;
@@ -50,7 +50,7 @@ void pkt_sys_debug_config(struct hfi_sys_set_property_pkt *pkt, u32 mode,

void pkt_sys_coverage_config(struct hfi_sys_set_property_pkt *pkt, u32 mode)
{
- pkt->hdr.size = sizeof(*pkt) + sizeof(u32);
+ pkt->hdr.size = struct_size(pkt, data, 2);
pkt->hdr.pkt_type = HFI_CMD_SYS_SET_PROPERTY;
pkt->num_properties = 1;
pkt->data[0] = HFI_PROPERTY_SYS_CONFIG_COVERAGE;
@@ -116,7 +116,7 @@ void pkt_sys_power_control(struct hfi_sys_set_property_pkt *pkt, u32 enable)
{
struct hfi_enable *hfi = (struct hfi_enable *)&pkt->data[1];

- pkt->hdr.size = sizeof(*pkt) + sizeof(*hfi) + sizeof(u32);
+ pkt->hdr.size = struct_size(pkt, data, 2) + sizeof(*hfi);
pkt->hdr.pkt_type = HFI_CMD_SYS_SET_PROPERTY;
pkt->num_properties = 1;
pkt->data[0] = HFI_PROPERTY_SYS_CODEC_POWER_PLANE_CTRL;
--
2.27.0


2021-06-02 19:59:44

by Kees Cook

[permalink] [raw]
Subject: Re: [PATCH][venus-for-next-v5.14] media: venus: hfi_cmds: Fix packet size calculation

On Tue, Jun 01, 2021 at 01:46:16PM -0500, Gustavo A. R. Silva wrote:
> Now that a one-element array was replaced with a flexible-array member
> in struct hfi_sys_set_property_pkt, use the struct_size() helper to
> correctly calculate the packet size.
>
> Fixes: 701e10b3fd9f ("media: venus: hfi_cmds.h: Replace one-element array with flexible-array member")
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> BTW... it seems that a similar problem is present in
> https://lore.kernel.org/linux-hardening/20210211001044.GA69612@embeddedor/
> and that is what is causing the regression. I will send v2 of that
> patch, shortly. Thanks.
>
> drivers/media/platform/qcom/venus/hfi_cmds.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/platform/qcom/venus/hfi_cmds.c b/drivers/media/platform/qcom/venus/hfi_cmds.c
> index 11a8347e5f5c..c86279e5d6e8 100644
> --- a/drivers/media/platform/qcom/venus/hfi_cmds.c
> +++ b/drivers/media/platform/qcom/venus/hfi_cmds.c
> @@ -27,7 +27,7 @@ void pkt_sys_idle_indicator(struct hfi_sys_set_property_pkt *pkt, u32 enable)
> {
> struct hfi_enable *hfi = (struct hfi_enable *)&pkt->data[1];
>
> - pkt->hdr.size = sizeof(*pkt) + sizeof(*hfi) + sizeof(u32);
> + pkt->hdr.size = struct_size(pkt, data, 2) + sizeof(*hfi);

I think this should be "1" not "2".

(i.e. there is a single "data" item, followed by an entire *hfi (which
starts immediate after data[0]).

> pkt->hdr.pkt_type = HFI_CMD_SYS_SET_PROPERTY;
> pkt->num_properties = 1;
> pkt->data[0] = HFI_PROPERTY_SYS_IDLE_INDICATOR;
> @@ -39,7 +39,7 @@ void pkt_sys_debug_config(struct hfi_sys_set_property_pkt *pkt, u32 mode,
> {
> struct hfi_debug_config *hfi;
>
> - pkt->hdr.size = sizeof(*pkt) + sizeof(*hfi) + sizeof(u32);
> + pkt->hdr.size = struct_size(pkt, data, 2) + sizeof(*hfi);

Same here.

> pkt->hdr.pkt_type = HFI_CMD_SYS_SET_PROPERTY;
> pkt->num_properties = 1;
> pkt->data[0] = HFI_PROPERTY_SYS_DEBUG_CONFIG;
> @@ -50,7 +50,7 @@ void pkt_sys_debug_config(struct hfi_sys_set_property_pkt *pkt, u32 mode,
>
> void pkt_sys_coverage_config(struct hfi_sys_set_property_pkt *pkt, u32 mode)
> {
> - pkt->hdr.size = sizeof(*pkt) + sizeof(u32);
> + pkt->hdr.size = struct_size(pkt, data, 2);

This looks correct.

> pkt->hdr.pkt_type = HFI_CMD_SYS_SET_PROPERTY;
> pkt->num_properties = 1;
> pkt->data[0] = HFI_PROPERTY_SYS_CONFIG_COVERAGE;
> @@ -116,7 +116,7 @@ void pkt_sys_power_control(struct hfi_sys_set_property_pkt *pkt, u32 enable)
> {
> struct hfi_enable *hfi = (struct hfi_enable *)&pkt->data[1];
>
> - pkt->hdr.size = sizeof(*pkt) + sizeof(*hfi) + sizeof(u32);
> + pkt->hdr.size = struct_size(pkt, data, 2) + sizeof(*hfi);

Also 1.

> pkt->hdr.pkt_type = HFI_CMD_SYS_SET_PROPERTY;
> pkt->num_properties = 1;
> pkt->data[0] = HFI_PROPERTY_SYS_CODEC_POWER_PLANE_CTRL;
> --
> 2.27.0
>

--
Kees Cook

2021-06-02 20:35:33

by Gustavo A. R. Silva

[permalink] [raw]
Subject: Re: [PATCH][venus-for-next-v5.14] media: venus: hfi_cmds: Fix packet size calculation



On 6/2/21 14:55, Kees Cook wrote:
> On Tue, Jun 01, 2021 at 01:46:16PM -0500, Gustavo A. R. Silva wrote:
>> Now that a one-element array was replaced with a flexible-array member
>> in struct hfi_sys_set_property_pkt, use the struct_size() helper to
>> correctly calculate the packet size.
>>
>> Fixes: 701e10b3fd9f ("media: venus: hfi_cmds.h: Replace one-element array with flexible-array member")
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>> ---
>> BTW... it seems that a similar problem is present in
>> https://lore.kernel.org/linux-hardening/20210211001044.GA69612@embeddedor/
>> and that is what is causing the regression. I will send v2 of that
>> patch, shortly. Thanks.
>>
>> drivers/media/platform/qcom/venus/hfi_cmds.c | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/media/platform/qcom/venus/hfi_cmds.c b/drivers/media/platform/qcom/venus/hfi_cmds.c
>> index 11a8347e5f5c..c86279e5d6e8 100644
>> --- a/drivers/media/platform/qcom/venus/hfi_cmds.c
>> +++ b/drivers/media/platform/qcom/venus/hfi_cmds.c
>> @@ -27,7 +27,7 @@ void pkt_sys_idle_indicator(struct hfi_sys_set_property_pkt *pkt, u32 enable)
>> {
>> struct hfi_enable *hfi = (struct hfi_enable *)&pkt->data[1];
>>
>> - pkt->hdr.size = sizeof(*pkt) + sizeof(*hfi) + sizeof(u32);
>> + pkt->hdr.size = struct_size(pkt, data, 2) + sizeof(*hfi);
>
> I think this should be "1" not "2".
>
> (i.e. there is a single "data" item, followed by an entire *hfi (which
> starts immediate after data[0]).

Yeah; I see your point. Here I just wanted to preserve the exact same size
as the original code, which turns out has a "benign" off-by-one issue.

I'll fix it up and respin.

Thanks!
--
Gustavo

>
>> pkt->hdr.pkt_type = HFI_CMD_SYS_SET_PROPERTY;
>> pkt->num_properties = 1;
>> pkt->data[0] = HFI_PROPERTY_SYS_IDLE_INDICATOR;
>> @@ -39,7 +39,7 @@ void pkt_sys_debug_config(struct hfi_sys_set_property_pkt *pkt, u32 mode,
>> {
>> struct hfi_debug_config *hfi;
>>
>> - pkt->hdr.size = sizeof(*pkt) + sizeof(*hfi) + sizeof(u32);
>> + pkt->hdr.size = struct_size(pkt, data, 2) + sizeof(*hfi);
>
> Same here.
>
>> pkt->hdr.pkt_type = HFI_CMD_SYS_SET_PROPERTY;
>> pkt->num_properties = 1;
>> pkt->data[0] = HFI_PROPERTY_SYS_DEBUG_CONFIG;
>> @@ -50,7 +50,7 @@ void pkt_sys_debug_config(struct hfi_sys_set_property_pkt *pkt, u32 mode,
>>
>> void pkt_sys_coverage_config(struct hfi_sys_set_property_pkt *pkt, u32 mode)
>> {
>> - pkt->hdr.size = sizeof(*pkt) + sizeof(u32);
>> + pkt->hdr.size = struct_size(pkt, data, 2);
>
> This looks correct.
>
>> pkt->hdr.pkt_type = HFI_CMD_SYS_SET_PROPERTY;
>> pkt->num_properties = 1;
>> pkt->data[0] = HFI_PROPERTY_SYS_CONFIG_COVERAGE;
>> @@ -116,7 +116,7 @@ void pkt_sys_power_control(struct hfi_sys_set_property_pkt *pkt, u32 enable)
>> {
>> struct hfi_enable *hfi = (struct hfi_enable *)&pkt->data[1];
>>
>> - pkt->hdr.size = sizeof(*pkt) + sizeof(*hfi) + sizeof(u32);
>> + pkt->hdr.size = struct_size(pkt, data, 2) + sizeof(*hfi);
>
> Also 1.
>
>> pkt->hdr.pkt_type = HFI_CMD_SYS_SET_PROPERTY;
>> pkt->num_properties = 1;
>> pkt->data[0] = HFI_PROPERTY_SYS_CODEC_POWER_PLANE_CTRL;
>> --
>> 2.27.0
>>
>

2021-06-02 22:05:09

by Gustavo A. R. Silva

[permalink] [raw]
Subject: Re: [PATCH][venus-for-next-v5.14] media: venus: hfi_cmds: Fix packet size calculation



On 6/2/21 15:34, Gustavo A. R. Silva wrote:
>
>
> On 6/2/21 14:55, Kees Cook wrote:
>> On Tue, Jun 01, 2021 at 01:46:16PM -0500, Gustavo A. R. Silva wrote:
>>> Now that a one-element array was replaced with a flexible-array member
>>> in struct hfi_sys_set_property_pkt, use the struct_size() helper to
>>> correctly calculate the packet size.
>>>
>>> Fixes: 701e10b3fd9f ("media: venus: hfi_cmds.h: Replace one-element array with flexible-array member")
>>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>>> ---
>>> BTW... it seems that a similar problem is present in
>>> https://lore.kernel.org/linux-hardening/20210211001044.GA69612@embeddedor/
>>> and that is what is causing the regression. I will send v2 of that
>>> patch, shortly. Thanks.
>>>
>>> drivers/media/platform/qcom/venus/hfi_cmds.c | 8 ++++----
>>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/media/platform/qcom/venus/hfi_cmds.c b/drivers/media/platform/qcom/venus/hfi_cmds.c
>>> index 11a8347e5f5c..c86279e5d6e8 100644
>>> --- a/drivers/media/platform/qcom/venus/hfi_cmds.c
>>> +++ b/drivers/media/platform/qcom/venus/hfi_cmds.c
>>> @@ -27,7 +27,7 @@ void pkt_sys_idle_indicator(struct hfi_sys_set_property_pkt *pkt, u32 enable)
>>> {
>>> struct hfi_enable *hfi = (struct hfi_enable *)&pkt->data[1];
>>>
>>> - pkt->hdr.size = sizeof(*pkt) + sizeof(*hfi) + sizeof(u32);
>>> + pkt->hdr.size = struct_size(pkt, data, 2) + sizeof(*hfi);
>>
>> I think this should be "1" not "2".
>>
>> (i.e. there is a single "data" item, followed by an entire *hfi (which
>> starts immediate after data[0]).
>
> Yeah; I see your point. Here I just wanted to preserve the exact same size
> as the original code, which turns out has a "benign" off-by-one issue.

And the reason why I say it's a "benign" off-by-one (which is actually off-by-four-bytes)
issue is because of this piece of code:

drivers/media/platform/qcom/venus/hfi_venus.c:
864 static int venus_sys_set_idle_message(struct venus_hfi_device *hdev,
865 bool enable)
866 {
867 struct hfi_sys_set_property_pkt *pkt;
868 u8 packet[IFACEQ_VAR_SMALL_PKT_SIZE];
869 int ret;
870
871 if (!enable)
872 return 0;
873
874 pkt = (struct hfi_sys_set_property_pkt *)packet;
875
876 pkt_sys_idle_indicator(pkt, enable);
877
878 ret = venus_iface_cmdq_write(hdev, pkt, false);
879 if (ret)
880 return ret;
881
882 return 0;
883 }

IFACEQ_VAR_SMALL_PKT_SIZE at line 868 is of size 100, which is greater than

sizeof(*pkt) + sizeof(*hfi) + sizeof(u32); in the original code:

drivers/media/platform/qcom/venus/hfi_cmds.c:
26 void pkt_sys_idle_indicator(struct hfi_sys_set_property_pkt *pkt, u32 enable)
27 {
28 struct hfi_enable *hfi = (struct hfi_enable *)&pkt->data[1];
29
30 pkt->hdr.size = sizeof(*pkt) + sizeof(*hfi) + sizeof(u32);
31 pkt->hdr.pkt_type = HFI_CMD_SYS_SET_PROPERTY;
32 pkt->num_properties = 1;
33 pkt->data[0] = HFI_PROPERTY_SYS_IDLE_INDICATOR;
34 hfi->enable = enable;
35 }

--
Gustavo

> I'll fix it up and respin.
>
> Thanks!
> --
> Gustavo