[PATCH] Fixed race condition at ip_vs.ko module init.

[Eduardo Blanco <ejblanco@xxxxxxxxxx>]

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@xxxxxxxxxx>
---
 net/netfilter/ipvs/ip_vs_ctl.c |   19 ++++++++++---------
 1 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 0f0c079..68624dc 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -3385,6 +3385,16 @@ int __init ip_vs_control_init(void)

        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");
@@ -3403,15 +3413,6 @@ int __init ip_vs_control_init(void)

        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 */
-- 
1.7.1
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