* [PATCH] ptp: prevent info leak to userspace
@ 2025-12-17 7:14 Kyle Zeng
2025-12-17 7:28 ` Gal Pressman
0 siblings, 1 reply; 3+ messages in thread
From: Kyle Zeng @ 2025-12-17 7:14 UTC (permalink / raw)
To: richardcochran, andrew+netdev, davem, edumazet, kuba, pabeni,
netdev
Somehow the `memset` is lost after refactor, which leaks a lot of kernel
stack data to userspace directly. This patch clears the reserved data
region to prevent the info leak.
Signed-off-by: Kyle Zeng <zengyhkyle@gmail.com>
---
drivers/ptp/ptp_chardev.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index c61cf9edac48..06f71011fb04 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -195,6 +195,8 @@ static long ptp_clock_getcaps(struct ptp_clock *ptp, void __user *arg)
if (caps.adjust_phase)
caps.max_phase_adj = ptp->info->getmaxphase(ptp->info);
+ memset(caps.rsv, 0, sizeof(caps.rsv));
+
return copy_to_user(arg, &caps, sizeof(caps)) ? -EFAULT : 0;
}
--
2.43.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] ptp: prevent info leak to userspace
2025-12-17 7:14 [PATCH] ptp: prevent info leak to userspace Kyle Zeng
@ 2025-12-17 7:28 ` Gal Pressman
2025-12-17 7:38 ` Kyle Zeng
0 siblings, 1 reply; 3+ messages in thread
From: Gal Pressman @ 2025-12-17 7:28 UTC (permalink / raw)
To: Kyle Zeng, richardcochran, andrew+netdev, davem, edumazet, kuba,
pabeni, netdev
On 17/12/2025 9:14, Kyle Zeng wrote:
> Somehow the `memset` is lost after refactor, which leaks a lot of kernel
> stack data to userspace directly. This patch clears the reserved data
> region to prevent the info leak.
>
> Signed-off-by: Kyle Zeng <zengyhkyle@gmail.com>
> ---
> drivers/ptp/ptp_chardev.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
> index c61cf9edac48..06f71011fb04 100644
> --- a/drivers/ptp/ptp_chardev.c
> +++ b/drivers/ptp/ptp_chardev.c
> @@ -195,6 +195,8 @@ static long ptp_clock_getcaps(struct ptp_clock *ptp, void __user *arg)
> if (caps.adjust_phase)
> caps.max_phase_adj = ptp->info->getmaxphase(ptp->info);
>
> + memset(caps.rsv, 0, sizeof(caps.rsv));
> +
> return copy_to_user(arg, &caps, sizeof(caps)) ? -EFAULT : 0;
> }
>
This is not how C works, the designated initializer clears the field
implicitly.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] ptp: prevent info leak to userspace
2025-12-17 7:28 ` Gal Pressman
@ 2025-12-17 7:38 ` Kyle Zeng
0 siblings, 0 replies; 3+ messages in thread
From: Kyle Zeng @ 2025-12-17 7:38 UTC (permalink / raw)
To: Gal Pressman
Cc: richardcochran, andrew+netdev, davem, edumazet, kuba, pabeni,
netdev
I apologize for the rookie mistake. Should've known better than this.
And thanks for the correction.
On Wed, Dec 17, 2025 at 12:28 AM Gal Pressman <gal@nvidia.com> wrote:
>
> On 17/12/2025 9:14, Kyle Zeng wrote:
> > Somehow the `memset` is lost after refactor, which leaks a lot of kernel
> > stack data to userspace directly. This patch clears the reserved data
> > region to prevent the info leak.
> >
> > Signed-off-by: Kyle Zeng <zengyhkyle@gmail.com>
> > ---
> > drivers/ptp/ptp_chardev.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
> > index c61cf9edac48..06f71011fb04 100644
> > --- a/drivers/ptp/ptp_chardev.c
> > +++ b/drivers/ptp/ptp_chardev.c
> > @@ -195,6 +195,8 @@ static long ptp_clock_getcaps(struct ptp_clock *ptp, void __user *arg)
> > if (caps.adjust_phase)
> > caps.max_phase_adj = ptp->info->getmaxphase(ptp->info);
> >
> > + memset(caps.rsv, 0, sizeof(caps.rsv));
> > +
> > return copy_to_user(arg, &caps, sizeof(caps)) ? -EFAULT : 0;
> > }
> >
>
> This is not how C works, the designated initializer clears the field
> implicitly.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2025-12-17 7:38 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2025-12-17 7:14 [PATCH] ptp: prevent info leak to userspace Kyle Zeng
2025-12-17 7:28 ` Gal Pressman
2025-12-17 7:38 ` Kyle Zeng
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