Re: [PATCH net-next v2 1/1] rtnetlink: extend RTEXT_FILTER_SKIP_STATS to IFLA_VF_INFO

[David Ahern <dsahern@gmail.com>]

On 1/26/21 10:40 AM, Edwin Peer wrote:
> This filter already exists for excluding IPv6 SNMP stats. Extend its
> definition to also exclude IFLA_VF_INFO stats in RTM_GETLINK.
> 
> This patch constitutes a partial fix for a netlink attribute nesting
> overflow bug in IFLA_VFINFO_LIST. By excluding the stats when the
> requester doesn't need them, the truncation of the VF list is avoided.
> 
> While it was technically only the stats added in commit c5a9f6f0ab40
> ("net/core: Add drop counters to VF statistics") breaking the camel's
> back, the appreciable size of the stats data should never have been
> included without due consideration for the maximum number of VFs
> supported by PCI.
> 
> Fixes: 3b766cd83232 ("net/core: Add reading VF statistics through the PF netdevice")
> Fixes: c5a9f6f0ab40 ("net/core: Add drop counters to VF statistics")
> Signed-off-by: Edwin Peer <edwin.peer@broadcom.com>
> ---
>  net/core/rtnetlink.c | 96 +++++++++++++++++++++++---------------------
>  1 file changed, 51 insertions(+), 45 deletions(-)
> 

looks reasonable to me - userspace is opting out of data it does not want.