Thread (3 messages) flat view 3 messages, 3 authors, 2010-10-21
STALE5778d

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

From: Eduardo Blanco <hidden>
Date: 2010-10-19 09:26:47
Also in: lvs-devel
Subsystem: ipvs, netfilter, networking [general], the rest · Maintainers: Simon Horman, Julian Anastasov, Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds

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]);
-	}
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