[PATCH] 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 <redacted>
---
 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]);
-	}

On Tue, Oct 19, 2010 at 10:26:47AM +0100, Eduardo Blanco wrote:

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 <redacted>

Thanks Eduardo.

Patrick, please consider pulling

git://git.kernel.org/pub/scm/linux/kernel/git/horms/lvs-test-2.6.git for-patrick

to get this change.

Am 19.10.2010 17:23, schrieb Simon Horman:

On Tue, Oct 19, 2010 at 10:26:47AM +0100, Eduardo Blanco wrote:

quoted

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 <redacted>

Thanks Eduardo.

Patrick, please consider pulling

git://git.kernel.org/pub/scm/linux/kernel/git/horms/lvs-test-2.6.git for-patrick

to get this change.

Pulled, thanks.