net: Add missing extra2 parameter for ip_default_ttl sysctl

Commit 76e6ebfb40a2455c18234dcb0f9df37533215461 ("netns: add namespace
parameter to rt_cache_flush") acceses the extra2 parameter of the
ip_default_ttl ctl_table, but it is never set to a meaningful
value. When e84f84f276473dcc673f360e8ff3203148bdf0e2 ("netns: place
rt_genid into struct net") is applied, we'll oops in
rt_cache_invalidate(). Set extra2 to init_net, to avoid that.

Reported-by: Marcin Slusarz <[email protected]>
Signed-off-by: Sven Wegener <[email protected]>
Tested-by: Marcin Slusarz <[email protected]>
Acked-by: Denis V. Lunev <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 770d827f5ab87a75ff6fcaa19a83f3fd7b7f112c..e0689fd7b798cb7b521ecf47355bd1028fcb510d 100644 (file)
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -232,6 +232,7 @@ static struct ctl_table ipv4_table[] = {
                .mode           = 0644,
                .proc_handler   = &ipv4_doint_and_flush,
                .strategy       = &ipv4_doint_and_flush_strategy,
+               .extra2         = &init_net,
        },
        {
                .ctl_name       = NET_IPV4_NO_PMTU_DISC,