2024-01-26 17:10:51

by Johan Hovold

[permalink] [raw]
Subject: [PATCH] HID: i2c-hid-of: fix NULL-deref on failed power up

A while back the I2C HID implementation was split in an ACPI and OF
part, but the new OF driver never initialises the client pointer which
is dereferenced on power-up failures.

Fixes: b33752c30023 ("HID: i2c-hid: Reorganize so ACPI and OF are separate modules")
Cc: [email protected] # 5.12
Cc: Douglas Anderson <[email protected]>
Signed-off-by: Johan Hovold <[email protected]>
---
drivers/hid/i2c-hid/i2c-hid-of.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/hid/i2c-hid/i2c-hid-of.c b/drivers/hid/i2c-hid/i2c-hid-of.c
index c4e1fa0273c8..8be4d576da77 100644
--- a/drivers/hid/i2c-hid/i2c-hid-of.c
+++ b/drivers/hid/i2c-hid/i2c-hid-of.c
@@ -87,6 +87,7 @@ static int i2c_hid_of_probe(struct i2c_client *client)
if (!ihid_of)
return -ENOMEM;

+ ihid_of->client = client;
ihid_of->ops.power_up = i2c_hid_of_power_up;
ihid_of->ops.power_down = i2c_hid_of_power_down;

--
2.43.0



2024-01-26 17:48:07

by Doug Anderson

[permalink] [raw]
Subject: Re: [PATCH] HID: i2c-hid-of: fix NULL-deref on failed power up

Hi,

On Fri, Jan 26, 2024 at 9:10 AM Johan Hovold <[email protected]> wrote:
>
> A while back the I2C HID implementation was split in an ACPI and OF
> part, but the new OF driver never initialises the client pointer which
> is dereferenced on power-up failures.
>
> Fixes: b33752c30023 ("HID: i2c-hid: Reorganize so ACPI and OF are separate modules")
> Cc: [email protected] # 5.12
> Cc: Douglas Anderson <[email protected]>
> Signed-off-by: Johan Hovold <[email protected]>
> ---
> drivers/hid/i2c-hid/i2c-hid-of.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/hid/i2c-hid/i2c-hid-of.c b/drivers/hid/i2c-hid/i2c-hid-of.c
> index c4e1fa0273c8..8be4d576da77 100644
> --- a/drivers/hid/i2c-hid/i2c-hid-of.c
> +++ b/drivers/hid/i2c-hid/i2c-hid-of.c
> @@ -87,6 +87,7 @@ static int i2c_hid_of_probe(struct i2c_client *client)
> if (!ihid_of)
> return -ENOMEM;
>
> + ihid_of->client = client;

Good catch and thanks for the fix. FWIW, I'd be OK w/

Reviewed-by: Douglas Anderson <[email protected]>

That being said, I'd be even happier if you simply removed the
"client" from the structure and removed the error printout.
regulator_bulk_enable() already prints error messages when a failure
happens and thus the error printout is redundant and wastes space.

-Doug

2024-01-26 17:53:29

by Jiri Kosina

[permalink] [raw]
Subject: Re: [PATCH] HID: i2c-hid-of: fix NULL-deref on failed power up

On Fri, 26 Jan 2024, Doug Anderson wrote:

> > A while back the I2C HID implementation was split in an ACPI and OF
> > part, but the new OF driver never initialises the client pointer which
> > is dereferenced on power-up failures.
> >
> > Fixes: b33752c30023 ("HID: i2c-hid: Reorganize so ACPI and OF are separate modules")
> > Cc: [email protected] # 5.12
> > Cc: Douglas Anderson <[email protected]>
> > Signed-off-by: Johan Hovold <[email protected]>
> > ---
> > drivers/hid/i2c-hid/i2c-hid-of.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/hid/i2c-hid/i2c-hid-of.c b/drivers/hid/i2c-hid/i2c-hid-of.c
> > index c4e1fa0273c8..8be4d576da77 100644
> > --- a/drivers/hid/i2c-hid/i2c-hid-of.c
> > +++ b/drivers/hid/i2c-hid/i2c-hid-of.c
> > @@ -87,6 +87,7 @@ static int i2c_hid_of_probe(struct i2c_client *client)
> > if (!ihid_of)
> > return -ENOMEM;
> >
> > + ihid_of->client = client;
>
> Good catch and thanks for the fix. FWIW, I'd be OK w/
>
> Reviewed-by: Douglas Anderson <[email protected]>

I've now queued this as a fix for 6.8 ....

> That being said, I'd be even happier if you simply removed the "client"
> from the structure and removed the error printout.
> regulator_bulk_enable() already prints error messages when a failure
> happens and thus the error printout is redundant and wastes space.

.. and this can be done for 6.9.

Thanks,

--
Jiri Kosina
SUSE Labs


2024-02-01 09:56:17

by Johan Hovold

[permalink] [raw]
Subject: Re: [PATCH] HID: i2c-hid-of: fix NULL-deref on failed power up

On Fri, Jan 26, 2024 at 09:47:23AM -0800, Doug Anderson wrote:
> On Fri, Jan 26, 2024 at 9:10 AM Johan Hovold <[email protected]> wrote:

> > A while back the I2C HID implementation was split in an ACPI and OF
> > part, but the new OF driver never initialises the client pointer which
> > is dereferenced on power-up failures.

> Good catch and thanks for the fix. FWIW, I'd be OK w/
>
> Reviewed-by: Douglas Anderson <[email protected]>
>
> That being said, I'd be even happier if you simply removed the
> "client" from the structure and removed the error printout.
> regulator_bulk_enable() already prints error messages when a failure
> happens and thus the error printout is redundant and wastes space.

True, but that error message does not include the device that tried to
use the regulator.

I actually hit this when adding dev_dbg() to the function in question.
For such cases, it's also convenient to have struct device easily
accessible so I think it should be ok to just leave this pointer in.

Johan