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@xxxxxxxxxxx>
> >> ---
> >> 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
