From: Gal Pressman <gal@nvidia.com>
To: Kyle Zeng <zengyhkyle@gmail.com>,
richardcochran@gmail.com, andrew+netdev@lunn.ch,
davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
pabeni@redhat.com, netdev@vger.kernel.org
Subject: Re: [PATCH] ptp: prevent info leak to userspace
Date: Wed, 17 Dec 2025 09:28:43 +0200 [thread overview]
Message-ID: <a5ef868d-b957-4124-a9ed-030f863dcd29@nvidia.com> (raw)
In-Reply-To: <aUJYSv6kqb9QauMI@westworld>
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.
next prev parent reply other threads:[~2025-12-17 7:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-17 7:14 [PATCH] ptp: prevent info leak to userspace Kyle Zeng
2025-12-17 7:28 ` Gal Pressman [this message]
2025-12-17 7:38 ` Kyle Zeng
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