On 7/5/24 8:52 AM, Nicolas Dichtel wrote:
> 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@xxxxxxxxxxxxxxx
> Fixes: 8cbb512c923d ("net: Add source address lookup op for VRF")
> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx>
> ---
> net/ipv4/fib_semantics.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
> index f669da98d11d..459082f4936d 100644
> --- a/net/ipv4/fib_semantics.c
> +++ b/net/ipv4/fib_semantics.c
> @@ -2270,6 +2270,13 @@ 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 = dev_get_by_index_rcu(net, fl4->flowi4_l3mdev);
long line length. separate setting the value:
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);
> + }
> }
