* [PATCH net v2] ipv4: don't set IPv6 only flags to IPv4 addresses
@ 2019-07-01 17:01 Matteo Croce
2019-07-01 17:19 ` David Ahern
2019-07-01 18:32 ` David Miller
0 siblings, 2 replies; 4+ messages in thread
From: Matteo Croce @ 2019-07-01 17:01 UTC (permalink / raw)
To: netdev; +Cc: linux-kernel, David S. Miller, Alexey Kuznetsov, Hideaki YOSHIFUJI
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>
---
net/ipv4/devinet.c | 8 ++++++++
1 file changed, 8 insertions(+)
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) &&
--
2.21.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH net v2] ipv4: don't set IPv6 only flags to IPv4 addresses
2019-07-01 17:01 [PATCH net v2] ipv4: don't set IPv6 only flags to IPv4 addresses Matteo Croce
@ 2019-07-01 17:19 ` David Ahern
2019-07-01 18:20 ` David Ahern
2019-07-01 18:32 ` David Miller
1 sibling, 1 reply; 4+ messages in thread
From: David Ahern @ 2019-07-01 17:19 UTC (permalink / raw)
To: Matteo Croce, netdev
Cc: linux-kernel, David S. Miller, Alexey Kuznetsov, Hideaki YOSHIFUJI
On 7/1/19 11:01 AM, Matteo Croce wrote:
> 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>
> ---
> net/ipv4/devinet.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> 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) &&
>
I guess at this point we can fail the address add, so this is the best
option. rtm_to_ifaddr could set a message in extack about invalid flags
- not fail the change, just warn the user that flags will be ignored.
Reviewed-by: David Ahern <dsahern@gmail.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net v2] ipv4: don't set IPv6 only flags to IPv4 addresses
2019-07-01 17:19 ` David Ahern
@ 2019-07-01 18:20 ` David Ahern
0 siblings, 0 replies; 4+ messages in thread
From: David Ahern @ 2019-07-01 18:20 UTC (permalink / raw)
To: Matteo Croce, netdev
Cc: linux-kernel, David S. Miller, Alexey Kuznetsov, Hideaki YOSHIFUJI
On 7/1/19 11:19 AM, David Ahern wrote:
> I guess at this point we can fail the address add, so this is the best
> option.
bleh, that should be 'can not'
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net v2] ipv4: don't set IPv6 only flags to IPv4 addresses
2019-07-01 17:01 [PATCH net v2] ipv4: don't set IPv6 only flags to IPv4 addresses Matteo Croce
2019-07-01 17:19 ` David Ahern
@ 2019-07-01 18:32 ` David Miller
1 sibling, 0 replies; 4+ messages in thread
From: David Miller @ 2019-07-01 18:32 UTC (permalink / raw)
To: mcroce; +Cc: netdev, linux-kernel, kuznet, yoshfuji
From: Matteo Croce <mcroce@redhat.com>
Date: Mon, 1 Jul 2019 19:01:55 +0200
> 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>
Applied and queued up for -stable, thanks Matteo.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2019-07-01 17:01 [PATCH net v2] ipv4: don't set IPv6 only flags to IPv4 addresses Matteo Croce
2019-07-01 17:19 ` David Ahern
2019-07-01 18:20 ` David Ahern
2019-07-01 18:32 ` David Miller
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