All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mukesh Ojha <mojha@codeaurora.org>
To: Kangjie Lu <kjlu@umn.edu>
Cc: pakki001@umn.edu, "K. Y. Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Sasha Levin <sashal@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org, linux-hyperv@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] hyperv: a potential NULL pointer dereference
Date: Wed, 20 Mar 2019 21:20:13 +0530	[thread overview]
Message-ID: <24cbb2df-6510-2ed8-deca-670ea934db68@codeaurora.org> (raw)
In-Reply-To: <20190314054651.1315-1-kjlu@umn.edu>


On 3/14/2019 11:16 AM, Kangjie Lu wrote:
> In case alloc_page, the fix returns -ENOMEM to avoid the potential
> NULL pointer dereference.
>
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
>   arch/x86/hyperv/hv_init.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index 7abb09e2eeb8..dfdb4ce1ae9c 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -102,9 +102,13 @@ static int hv_cpu_init(unsigned int cpu)
>   	u64 msr_vp_index;
>   	struct hv_vp_assist_page **hvp = &hv_vp_assist_page[smp_processor_id()];
>   	void **input_arg;
> +	struct page *pg;
>   
>   	input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
> -	*input_arg = page_address(alloc_page(GFP_KERNEL));
> +	pg = alloc_page(GFP_KERNEL);
> +	if (unlikely(!pg))
> +		return -ENOMEM;
> +	*input_arg = page_address(pg);
>   
>   	hv_get_vp_index(msr_vp_index);



Looks good to me.
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>


Thanks.
Mukesh


>   

  parent reply	other threads:[~2019-03-20 15:50 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-14  5:46 [PATCH] hyperv: a potential NULL pointer dereference Kangjie Lu
2019-03-14 14:56 ` KY Srinivasan
2019-03-20 10:20   ` Thomas Gleixner
2019-03-20 14:40     ` KY Srinivasan
2019-03-20 15:50 ` Mukesh Ojha [this message]
2019-03-21 11:30 ` [tip:x86/urgent] x86/hyperv: Prevent " tip-bot for Kangjie Lu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=24cbb2df-6510-2ed8-deca-670ea934db68@codeaurora.org \
    --to=mojha@codeaurora.org \
    --cc=bp@alien8.de \
    --cc=haiyangz@microsoft.com \
    --cc=hpa@zytor.com \
    --cc=kjlu@umn.edu \
    --cc=kys@microsoft.com \
    --cc=linux-hyperv@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=pakki001@umn.edu \
    --cc=sashal@kernel.org \
    --cc=sthemmin@microsoft.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.