From: Greg KH <gregkh@linuxfoundation.org>
To: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Cc: stephen@networkplumber.org, kys@microsoft.com,
haiyangz@microsoft.com, sthemmin@microsoft.com,
wei.liu@kernel.org, decui@microsoft.com, davem@davemloft.net,
kuba@kernel.org, ast@kernel.org, daniel@iogearbox.net,
hawk@kernel.org, john.fastabend@gmail.com, andrii@kernel.org,
kafai@fb.com, songliubraving@fb.com, yhs@fb.com,
kpsingh@kernel.org, linux-hyperv@vger.kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
bpf@vger.kernel.org
Subject: Re: [PATCH] hv_netvsc: Add check for kvmalloc_array
Date: Mon, 14 Mar 2022 08:38:49 +0100 [thread overview]
Message-ID: <Yi7xCSdtTmSgIcgp@kroah.com> (raw)
In-Reply-To: <20220314073349.2501022-1-jiasheng@iscas.ac.cn>
On Mon, Mar 14, 2022 at 03:33:49PM +0800, Jiasheng Jiang wrote:
> On Fri, Mar 11, 2022 at 02:43:48PM +0800, Greg KH wrote:
> >> As the potential failure of the kvmalloc_array(),
> >> it should be better to check and restore the 'data'
> >> if fails in order to avoid the dereference of the
> >> NULL pointer.
> >>
> >> Fixes: 6ae746711263 ("hv_netvsc: Add per-cpu ethtool stats for netvsc")
> >> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> >> ---
> >> drivers/net/hyperv/netvsc_drv.c | 6 ++++++
> >> 1 file changed, 6 insertions(+)
> >>
> >> diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
> >> index 3646469433b1..018c4a5f6f44 100644
> >> --- a/drivers/net/hyperv/netvsc_drv.c
> >> +++ b/drivers/net/hyperv/netvsc_drv.c
> >> @@ -1587,6 +1587,12 @@ static void netvsc_get_ethtool_stats(struct net_device *dev,
> >> pcpu_sum = kvmalloc_array(num_possible_cpus(),
> >> sizeof(struct netvsc_ethtool_pcpu_stats),
> >> GFP_KERNEL);
> >> + if (!pcpu_sum) {
> >> + for (j = 0; j < i; j++)
> >> + data[j] = 0;
> >> + return;
> >> + }
> >
> >How did you test this to verify it is correct?
>
> Thanks, I have tested the patch by kernel_patch_verify,
What is that?
> and all the tests are passed.
What tests exactly? How did you fail this allocation?
thanks,
greg k-h
next prev parent reply other threads:[~2022-03-14 7:39 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-14 7:33 [PATCH] hv_netvsc: Add check for kvmalloc_array Jiasheng Jiang
2022-03-14 7:38 ` Greg KH [this message]
-- strict thread matches above, loose matches on Subject: below --
2022-03-14 8:35 Jiasheng Jiang
2022-03-14 17:12 ` Jakub Kicinski
2022-03-14 8:05 Jiasheng Jiang
2022-03-14 8:13 ` Greg KH
2022-03-14 1:56 Jiasheng Jiang
2022-03-11 3:20 Jiasheng Jiang
2022-03-11 3:20 Jiasheng Jiang
2022-03-11 6:43 ` Greg KH
2022-03-11 17:25 ` Stephen Hemminger
2022-03-11 2:43 Jiasheng Jiang
2022-03-11 3:00 ` Stephen Hemminger
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