Commit 2e605463 authored by Matteo Croce's avatar Matteo Croce Committed by David S. Miller

ipv4: don't set IPv6 only flags to IPv4 addresses

Avoid the situation where an IPV6 only flag is applied to an IPv4 address:

    # ip addr add 192.0.2.1/24 dev dummy0 nodad home mngtmpaddr noprefixroute
    # ip -4 addr show dev dummy0
    2: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
        inet 192.0.2.1/24 scope global noprefixroute dummy0
           valid_lft forever preferred_lft forever

Or worse, by sending a malicious netlink command:

    # ip -4 addr show dev dummy0
    2: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
        inet 192.0.2.1/24 scope global nodad optimistic dadfailed home tentative mngtmpaddr noprefixroute stable-privacy dummy0
           valid_lft forever preferred_lft forever
Signed-off-by: default avatarMatteo Croce <mcroce@redhat.com>
Reviewed-by: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 88405680
...@@ -62,6 +62,11 @@ ...@@ -62,6 +62,11 @@
#include <net/net_namespace.h> #include <net/net_namespace.h>
#include <net/addrconf.h> #include <net/addrconf.h>
#define IPV6ONLY_FLAGS \
(IFA_F_NODAD | IFA_F_OPTIMISTIC | IFA_F_DADFAILED | \
IFA_F_HOMEADDRESS | IFA_F_TENTATIVE | \
IFA_F_MANAGETEMPADDR | IFA_F_STABLE_PRIVACY)
static struct ipv4_devconf ipv4_devconf = { static struct ipv4_devconf ipv4_devconf = {
.data = { .data = {
[IPV4_DEVCONF_ACCEPT_REDIRECTS - 1] = 1, [IPV4_DEVCONF_ACCEPT_REDIRECTS - 1] = 1,
...@@ -468,6 +473,9 @@ static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh, ...@@ -468,6 +473,9 @@ static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh,
ifa->ifa_flags &= ~IFA_F_SECONDARY; ifa->ifa_flags &= ~IFA_F_SECONDARY;
last_primary = &in_dev->ifa_list; last_primary = &in_dev->ifa_list;
/* Don't set IPv6 only flags to IPv4 addresses */
ifa->ifa_flags &= ~IPV6ONLY_FLAGS;
for (ifap = &in_dev->ifa_list; (ifa1 = *ifap) != NULL; for (ifap = &in_dev->ifa_list; (ifa1 = *ifap) != NULL;
ifap = &ifa1->ifa_next) { ifap = &ifa1->ifa_next) {
if (!(ifa1->ifa_flags & IFA_F_SECONDARY) && if (!(ifa1->ifa_flags & IFA_F_SECONDARY) &&
......
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