Fixed race condition at ip_vs.ko module init.
Lists were initialized after the module was registered. Multiple ipvsadm
processes at module load triggered a race condition that resulted in a null
pointer dereference in do_ip_vs_get_ctl(). As a result, __ip_vs_mutex
was left locked preventing all further ipvsadm commands.
Signed-off-by: Eduardo J. Blanco <ejblanco@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index a697591..0b884d3 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -3400,6 +3400,16 @@
EnterFunction(2);
+ /* Initialize ip_vs_svc_table, ip_vs_svc_fwm_table, ip_vs_rtable */
+ for(idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
+ INIT_LIST_HEAD(&ip_vs_svc_table[idx]);
+ INIT_LIST_HEAD(&ip_vs_svc_fwm_table[idx]);
+ }
+ for(idx = 0; idx < IP_VS_RTAB_SIZE; idx++) {
+ INIT_LIST_HEAD(&ip_vs_rtable[idx]);
+ }
+ smp_wmb();
+
ret = nf_register_sockopt(&ip_vs_sockopts);
if (ret) {
pr_err("cannot register sockopt.\n");
@@ -3418,15 +3428,6 @@
sysctl_header = register_sysctl_paths(net_vs_ctl_path, vs_vars);
- /* Initialize ip_vs_svc_table, ip_vs_svc_fwm_table, ip_vs_rtable */
- for(idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- INIT_LIST_HEAD(&ip_vs_svc_table[idx]);
- INIT_LIST_HEAD(&ip_vs_svc_fwm_table[idx]);
- }
- for(idx = 0; idx < IP_VS_RTAB_SIZE; idx++) {
- INIT_LIST_HEAD(&ip_vs_rtable[idx]);
- }
-
ip_vs_new_estimator(&ip_vs_stats);
/* Hook the defense timer */