ipv4: fix source address selection with route leak

commit 6807352353 upstream.

By default, an address assigned to the output interface is selected when
the source address is not specified. This is problematic when a route,
configured in a vrf, uses an interface from another vrf (aka route leak).
The original vrf does not own the selected source address.

Let's add a check against the output interface and call the appropriate
function to select the source address.

CC: stable@vger.kernel.org
Fixes: 8cbb512c92 ("net: Add source address lookup op for VRF")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20240710081521.3809742-2-nicolas.dichtel@6wind.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Nicolas Dichtel 2024-07-10 10:14:27 +02:00 committed by Greg Kroah-Hartman
parent 5c07084001
commit 0aa47c27f8

View file

@ -2270,6 +2270,15 @@ void fib_select_path(struct net *net, struct fib_result *res,
fib_select_default(fl4, res);
check_saddr:
if (!fl4->saddr)
fl4->saddr = fib_result_prefsrc(net, res);
if (!fl4->saddr) {
struct net_device *l3mdev;
l3mdev = dev_get_by_index_rcu(net, fl4->flowi4_l3mdev);
if (!l3mdev ||
l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) == l3mdev)
fl4->saddr = fib_result_prefsrc(net, res);
else
fl4->saddr = inet_select_addr(l3mdev, 0, RT_SCOPE_LINK);
}
}