From 5cdda5f1d6adde02da591ca2196f20289977dc56 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Mon, 24 Jun 2019 15:29:23 +0200 Subject: [PATCH] ipv4: enable route flushing in network namespaces Tools such as vpnc try to flush routes when run inside network namespaces by writing 1 into /proc/sys/net/ipv4/route/flush. This currently does not work because flush is not enabled in non-initial network namespaces. Since routes are per network namespace it is safe to enable /proc/sys/net/ipv4/route/flush in there. Link: https://github.com/lxc/lxd/issues/4257 Signed-off-by: Christian Brauner Signed-off-by: David S. Miller --- net/ipv4/route.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index a3e466b6a60c..bbd55c7f6b2e 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -3326,9 +3326,11 @@ static struct ctl_table ipv4_route_table[] = { { } }; +static const char ipv4_route_flush_procname[] = "flush"; + static struct ctl_table ipv4_route_flush_table[] = { { - .procname = "flush", + .procname = ipv4_route_flush_procname, .maxlen = sizeof(int), .mode = 0200, .proc_handler = ipv4_sysctl_rtcache_flush, @@ -3346,9 +3348,11 @@ static __net_init int sysctl_route_net_init(struct net *net) if (!tbl) goto err_dup; - /* Don't export sysctls to unprivileged users */ - if (net->user_ns != &init_user_ns) - tbl[0].procname = NULL; + /* Don't export non-whitelisted sysctls to unprivileged users */ + if (net->user_ns != &init_user_ns) { + if (tbl[0].procname != ipv4_route_flush_procname) + tbl[0].procname = NULL; + } } tbl[0].extra1 = net; -- 2.30.2