diff options
| author | Matteo Croce <mcroce@redhat.com> | 2019-07-01 19:01:55 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-07-01 20:31:38 +0200 |
| commit | 2e60546368165c2449564d71f6005dda9205b5fb (patch) | |
| tree | e1f5449e770ac26eae92eef2b752e1f5fcb47794 | |
| parent | net:gue.h:Fix shifting signed 32-bit value by 31 bits problem (diff) | |
| download | linux-2e60546368165c2449564d71f6005dda9205b5fb.tar.xz linux-2e60546368165c2449564d71f6005dda9205b5fb.zip | |
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: Matteo Croce <mcroce@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/devinet.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index c6bd0f7a020a..c5ebfa199794 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -62,6 +62,11 @@ #include <net/net_namespace.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 = { .data = { [IPV4_DEVCONF_ACCEPT_REDIRECTS - 1] = 1, @@ -468,6 +473,9 @@ static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh, ifa->ifa_flags &= ~IFA_F_SECONDARY; 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; ifap = &ifa1->ifa_next) { if (!(ifa1->ifa_flags & IFA_F_SECONDARY) && |