Re: [PATCH 1/2] rtnetlink: Warn when interface's information won't fit in our packet

Jiri Pirko
2014-04-24T15:49:39Z

Thu, Apr 24, 2014 at 02:22:35AM CEST, david@gibson.dropbear.id.au wrote:
>Without IFLA_EXT_MASK specified, the information reported for a single
>interface in response to RTM_GETLINK is expected to fit within a netlink
>packet of NLMSG_GOODSIZE.
>
>If it doesn't, however, things will go badly wrong, When listing all
>interfaces, netlink_dump() will incorrectly treat -EMSGSIZE on the first
>message in a packet as the end of the listing and omit information for
>that interface and all subsequent ones. This can cause getifaddrs(3) to
>enter an infinite loop.
>
>This patch won't fix the problem, but it will WARN_ON() making it easier to
>track down what's going wrong.
>
>Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

Reviewed-by: Jiri Pirko <jpirko@redhat.com>