2022-01-11 09:09:20

by Pawel Laszczak

Subject: [PATCH] usb: cdnsp: Fix segmentation fault in cdns_lost_power function

From: Pawel Laszczak <[email protected]>

CDNSP driver read not initialized cdns->otg_v0_regs
which lead to segmentation fault. Patch fixes this issue.

Fixes: 2cf2581cd229 ("usb: cdns3: add power lost support for system resume")
cc: <[email protected]>
Signed-off-by: Pawel Laszczak <[email protected]>
---
drivers/usb/cdns3/drd.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/cdns3/drd.c b/drivers/usb/cdns3/drd.c
index 55c73b1d8704..d00ff98dffab 100644
--- a/drivers/usb/cdns3/drd.c
+++ b/drivers/usb/cdns3/drd.c
@@ -483,11 +483,11 @@ int cdns_drd_exit(struct cdns *cdns)
/* Indicate the cdns3 core was power lost before */
bool cdns_power_is_lost(struct cdns *cdns)
{
- if (cdns->version == CDNS3_CONTROLLER_V1) {
- if (!(readl(&cdns->otg_v1_regs->simulate) & BIT(0)))
+ if (cdns->version == CDNS3_CONTROLLER_V0) {
+ if (!(readl(&cdns->otg_v0_regs->simulate) & BIT(0)))
return true;
} else {
- if (!(readl(&cdns->otg_v0_regs->simulate) & BIT(0)))
+ if (!(readl(&cdns->otg_v1_regs->simulate) & BIT(0)))
return true;
}
return false;
--
2.25.1

2022-01-12 12:56:28

by Peter Chen

Subject: Re: [PATCH] usb: cdnsp: Fix segmentation fault in cdns_lost_power function

On 22-01-11 10:07:37, Pawel Laszczak wrote:
> From: Pawel Laszczak <[email protected]>
>
> CDNSP driver read not initialized cdns->otg_v0_regs
> which lead to segmentation fault. Patch fixes this issue.
>
> Fixes: 2cf2581cd229 ("usb: cdns3: add power lost support for system resume")
> cc: <[email protected]>
> Signed-off-by: Pawel Laszczak <[email protected]>
> ---
> drivers/usb/cdns3/drd.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/cdns3/drd.c b/drivers/usb/cdns3/drd.c
> index 55c73b1d8704..d00ff98dffab 100644
> --- a/drivers/usb/cdns3/drd.c
> +++ b/drivers/usb/cdns3/drd.c
> @@ -483,11 +483,11 @@ int cdns_drd_exit(struct cdns *cdns)
> /* Indicate the cdns3 core was power lost before */
> bool cdns_power_is_lost(struct cdns *cdns)
> {
> - if (cdns->version == CDNS3_CONTROLLER_V1) {
> - if (!(readl(&cdns->otg_v1_regs->simulate) & BIT(0)))
> + if (cdns->version == CDNS3_CONTROLLER_V0) {
> + if (!(readl(&cdns->otg_v0_regs->simulate) & BIT(0)))
> return true;
> } else {
> - if (!(readl(&cdns->otg_v0_regs->simulate) & BIT(0)))
> + if (!(readl(&cdns->otg_v1_regs->simulate) & BIT(0)))
> return true;
> }
> return false;
> --

Pawel, may this lead cdns driver segment fault?

--

Thanks,
Peter Chen

2022-01-12 13:14:07

by Pawel Laszczak

Subject: RE: [PATCH] usb: cdnsp: Fix segmentation fault in cdns_lost_power function

>
>On 22-01-11 10:07:37, Pawel Laszczak wrote:
>> From: Pawel Laszczak <[email protected]>
>>
>> CDNSP driver read not initialized cdns->otg_v0_regs
>> which lead to segmentation fault. Patch fixes this issue.
>>
>> Fixes: 2cf2581cd229 ("usb: cdns3: add power lost support for system resume")
>> cc: <[email protected]>
>> Signed-off-by: Pawel Laszczak <[email protected]>
>> ---
>> drivers/usb/cdns3/drd.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/usb/cdns3/drd.c b/drivers/usb/cdns3/drd.c
>> index 55c73b1d8704..d00ff98dffab 100644
>> --- a/drivers/usb/cdns3/drd.c
>> +++ b/drivers/usb/cdns3/drd.c
>> @@ -483,11 +483,11 @@ int cdns_drd_exit(struct cdns *cdns)
>> /* Indicate the cdns3 core was power lost before */
>> bool cdns_power_is_lost(struct cdns *cdns)
>> {
>> - if (cdns->version == CDNS3_CONTROLLER_V1) {
>> - if (!(readl(&cdns->otg_v1_regs->simulate) & BIT(0)))
>> + if (cdns->version == CDNS3_CONTROLLER_V0) {
>> + if (!(readl(&cdns->otg_v0_regs->simulate) & BIT(0)))
>> return true;
>> } else {
>> - if (!(readl(&cdns->otg_v0_regs->simulate) & BIT(0)))
>> + if (!(readl(&cdns->otg_v1_regs->simulate) & BIT(0)))
>> return true;
>> }
>> return false;
>> --
>
>Pawel, may this lead cdns driver segment fault?
>

Yes, we can observe such situation for CDNSP driver on simulation.
As you know, it is a common code and driver support two version of register map for DRD.

If cdns->version == CDNSP_CONTROLLER_V2 (for CNDSP) the cdns->otg_v0_regs is NULL.
It will cause segmentation fault.

I didn't analyze why this issue was not observed on my FPGA testing board.

Regards,

Pawel Laszczak