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Sabrina Dubroca authored
[ Upstream commit feadc4b6 ] Currently, nla_put_iflink() doesn't put the IFLA_LINK attribute when iflink == ifindex. In some cases, a device can be created in a different netns with the same ifindex as its parent. That device will not dump its IFLA_LINK attribute, which can confuse some userspace software that expects it. For example, if the last ifindex created in init_net and foo are both 8, these commands will trigger the issue: ip link add parent type dummy # ifindex 9 ip link add link parent netns foo type macvlan # ifindex 9 in ns foo So, in case a device puts the IFLA_LINK_NETNSID attribute in a dump, always put the IFLA_LINK attribute as well. Thanks to Dan Winship for analyzing the original OpenShift bug down to the missing netlink attribute. v2: change Fixes tag, it's been here forever, as Nicolas Dichtel said add Nicolas' ack v3: change Fixes tag fix subject typo, spotted by Edward Cree Analyzed-by:
Dan Winship <danw@redhat.com> Fixes: d8a5ec67 ("[NET]: netlink support for moving devices between network namespaces.") Signed-off-by:
Sabrina Dubroca <sd@queasysnail.net> Acked-by:
Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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