From: Paolo Abeni pabeni@redhat.com
[ Upstream commit 0b834ba00ab5337e938c727e216e1f5249794717 ]
Since commit af4d768ad28c ("net/ipv4: Add support for specifying metric of connected routes"), when updating an IP address with a different metric, the associated connected route is updated, too.
Still, the mentioned commit doesn't handle properly some corner cases:
$ ip addr add dev eth0 192.168.1.0/24 $ ip addr add dev eth0 192.168.2.1/32 peer 192.168.2.2 $ ip addr add dev eth0 192.168.3.1/24 $ ip addr change dev eth0 192.168.1.0/24 metric 10 $ ip addr change dev eth0 192.168.2.1/32 peer 192.168.2.2 metric 10 $ ip addr change dev eth0 192.168.3.1/24 metric 10 $ ip -4 route 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.0 192.168.2.2 dev eth0 proto kernel scope link src 192.168.2.1 192.168.3.0/24 dev eth0 proto kernel scope link src 192.168.2.1 metric 10
Only the last route is correctly updated.
The problem is the current test in fib_modify_prefix_metric():
if (!(dev->flags & IFF_UP) || ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || ipv4_is_zeronet(prefix) || prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32)
Which should be the logical 'not' of the pre-existing test in fib_add_ifaddr():
if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && (prefix != addr || ifa->ifa_prefixlen < 32))
To properly negate the original expression, we need to change the last logical 'or' to a logical 'and'.
Fixes: af4d768ad28c ("net/ipv4: Add support for specifying metric of connected routes") Reported-and-suggested-by: Beniamino Galvani bgalvani@redhat.com Signed-off-by: Paolo Abeni pabeni@redhat.com Reviewed-by: David Ahern dsahern@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/fib_frontend.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -946,7 +946,7 @@ void fib_modify_prefix_metric(struct in_ if (!(dev->flags & IFF_UP) || ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || ipv4_is_zeronet(prefix) || - prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32) + (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32)) return;
/* add the new */