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authorMatteo Croce <mcroce@redhat.com>2019-07-01 20:01:55 +0300
committerDavid S. Miller <davem@davemloft.net>2019-07-01 21:31:38 +0300
commit2e60546368165c2449564d71f6005dda9205b5fb (patch)
treee1f5449e770ac26eae92eef2b752e1f5fcb47794
parent88405680ec57c35f5886dbb81b3f6f638f74f40d (diff)
downloadlinux-2e60546368165c2449564d71f6005dda9205b5fb.tar.xz
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.c8
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) &&