Thread (9 messages) read the whole thread 9 messages, 2 authors, 2021-04-12
STALE1935d

Revision v1 of 139 in this series.

Revisions (139)
  1. v1 [diff vs current]
  2. v1 [diff vs current]
  3. v1 [diff vs current]
  4. v1 [diff vs current]
  5. v1 [diff vs current]
  6. v1 [diff vs current]
  7. v1 [diff vs current]
  8. v1 [diff vs current]
  9. v1 [diff vs current]
  10. v1 [diff vs current]
  11. v1 [diff vs current]
  12. v1 [diff vs current]
  13. v1 [diff vs current]
  14. v1 [diff vs current]
  15. v1 [diff vs current]
  16. v1 [diff vs current]
  17. v1 [diff vs current]
  18. v1 [diff vs current]
  19. v1 [diff vs current]
  20. v1 [diff vs current]
  21. v1 [diff vs current]
  22. v1 [diff vs current]
  23. v1 [diff vs current]
  24. v1 [diff vs current]
  25. v1 [diff vs current]
  26. v1 [diff vs current]
  27. v1 [diff vs current]
  28. v1 [diff vs current]
  29. v1 [diff vs current]
  30. v1 [diff vs current]
  31. v1 [diff vs current]
  32. v1 [diff vs current]
  33. v1 [diff vs current]
  34. v1 [diff vs current]
  35. v1 [diff vs current]
  36. v1 [diff vs current]
  37. v1 [diff vs current]
  38. v1 [diff vs current]
  39. v1 [diff vs current]
  40. v1 [diff vs current]
  41. v1 [diff vs current]
  42. v1 [diff vs current]
  43. v1 [diff vs current]
  44. v1 [diff vs current]
  45. v1 [diff vs current]
  46. v1 [diff vs current]
  47. v1 [diff vs current]
  48. v1 [diff vs current]
  49. v1 [diff vs current]
  50. v1 [diff vs current]
  51. v1 [diff vs current]
  52. v1 [diff vs current]
  53. v1 [diff vs current]
  54. v1 [diff vs current]
  55. v1 [diff vs current]
  56. v1 [diff vs current]
  57. v1 [diff vs current]
  58. v1 [diff vs current]
  59. v1 [diff vs current]
  60. v1 [diff vs current]
  61. v1 [diff vs current]
  62. v1 [diff vs current]
  63. v1 [diff vs current]
  64. v1 [diff vs current]
  65. v1 [diff vs current]
  66. v1 [diff vs current]
  67. v1 [diff vs current]
  68. v1 [diff vs current]
  69. v1 [diff vs current]
  70. v1 [diff vs current]
  71. v1 [diff vs current]
  72. v1 [diff vs current]
  73. v1 [diff vs current]
  74. v1 [diff vs current]
  75. v1 current
  76. v1 [diff vs current]
  77. v1 [diff vs current]
  78. v1 [diff vs current]
  79. v1 [diff vs current]
  80. v1 [diff vs current]
  81. v2 [diff vs current]
  82. v1 [diff vs current]
  83. v1 [diff vs current]
  84. v1 [diff vs current]
  85. v1 [diff vs current]
  86. v1 [diff vs current]
  87. v1 [diff vs current]
  88. v1 [diff vs current]
  89. v1 [diff vs current]
  90. v1 [diff vs current]
  91. v2 [diff vs current]
  92. v1 [diff vs current]
  93. v1 [diff vs current]
  94. v1 [diff vs current]
  95. v1 [diff vs current]
  96. v1 [diff vs current]
  97. v1 [diff vs current]
  98. v1 [diff vs current]
  99. v1 [diff vs current]
  100. v1 [diff vs current]
  101. v1 [diff vs current]
  102. v1 [diff vs current]
  103. v1 [diff vs current]
  104. v1 [diff vs current]
  105. v1 [diff vs current]
  106. v1 [diff vs current]
  107. v1 [diff vs current]
  108. v1 [diff vs current]
  109. v1 [diff vs current]
  110. v1 [diff vs current]
  111. v2 [diff vs current]
  112. v1 [diff vs current]
  113. v1 [diff vs current]
  114. v1 [diff vs current]
  115. v2 [diff vs current]
  116. v1 [diff vs current]
  117. v1 [diff vs current]
  118. v1 [diff vs current]
  119. v1 [diff vs current]
  120. v1 [diff vs current]
  121. v2 [diff vs current]
  122. v3 [diff vs current]
  123. v1 [diff vs current]
  124. v1 [diff vs current]
  125. v1 [diff vs current]
  126. v2 [diff vs current]
  127. v1 [diff vs current]
  128. v1 [diff vs current]
  129. v1 [diff vs current]
  130. v1 [diff vs current]
  131. v2 [diff vs current]
  132. v1 [diff vs current]
  133. v2 [diff vs current]
  134. v1 [diff vs current]
  135. v1 [diff vs current]
  136. v1 [diff vs current]
  137. v1 [diff vs current]
  138. v2 [diff vs current]
  139. v1 [diff vs current]

[PATCH net 5/7] netfilter: arp_tables: add pre_exit hook for table unregister

From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2021-04-12 22:31:18
Also in: netfilter-devel
Subsystem: netfilter, networking [general], the rest · Maintainers: Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds 

From: Florian Westphal <fw@strlen.de>

Same problem that also existed in iptables/ip(6)tables, when
arptable_filter is removed there is no longer a wait period before the
table/ruleset is free'd.

Unregister the hook in pre_exit, then remove the table in the exit
function.
This used to work correctly because the old nf_hook_unregister API
did unconditional synchronize_net.

The per-net hook unregister function uses call_rcu instead.

Fixes: b9e69e127397 ("netfilter: xtables: don't hook tables by default")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/linux/netfilter_arp/arp_tables.h |  5 +++--
 net/ipv4/netfilter/arp_tables.c          |  9 +++++++--
 net/ipv4/netfilter/arptable_filter.c     | 10 +++++++++-
 3 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/include/linux/netfilter_arp/arp_tables.h b/include/linux/netfilter_arp/arp_tables.h
index 7d3537c40ec9..26a13294318c 100644
--- a/include/linux/netfilter_arp/arp_tables.h
+++ b/include/linux/netfilter_arp/arp_tables.h
@@ -52,8 +52,9 @@ extern void *arpt_alloc_initial_table(const struct xt_table *);
 int arpt_register_table(struct net *net, const struct xt_table *table,
 			const struct arpt_replace *repl,
 			const struct nf_hook_ops *ops, struct xt_table **res);
-void arpt_unregister_table(struct net *net, struct xt_table *table,
-			   const struct nf_hook_ops *ops);
+void arpt_unregister_table(struct net *net, struct xt_table *table);
+void arpt_unregister_table_pre_exit(struct net *net, struct xt_table *table,
+				    const struct nf_hook_ops *ops);
 extern unsigned int arpt_do_table(struct sk_buff *skb,
 				  const struct nf_hook_state *state,
 				  struct xt_table *table);
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index d1e04d2b5170..6c26533480dd 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1539,10 +1539,15 @@ int arpt_register_table(struct net *net,
 	return ret;
 }
 
-void arpt_unregister_table(struct net *net, struct xt_table *table,
-			   const struct nf_hook_ops *ops)
+void arpt_unregister_table_pre_exit(struct net *net, struct xt_table *table,
+				    const struct nf_hook_ops *ops)
 {
 	nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
+}
+EXPORT_SYMBOL(arpt_unregister_table_pre_exit);
+
+void arpt_unregister_table(struct net *net, struct xt_table *table)
+{
 	__arpt_unregister_table(net, table);
 }
 
diff --git a/net/ipv4/netfilter/arptable_filter.c b/net/ipv4/netfilter/arptable_filter.c
index c216b9ad3bb2..6c300ba5634e 100644
--- a/net/ipv4/netfilter/arptable_filter.c
+++ b/net/ipv4/netfilter/arptable_filter.c
@@ -56,16 +56,24 @@ static int __net_init arptable_filter_table_init(struct net *net)
 	return err;
 }
 
+static void __net_exit arptable_filter_net_pre_exit(struct net *net)
+{
+	if (net->ipv4.arptable_filter)
+		arpt_unregister_table_pre_exit(net, net->ipv4.arptable_filter,
+					       arpfilter_ops);
+}
+
 static void __net_exit arptable_filter_net_exit(struct net *net)
 {
 	if (!net->ipv4.arptable_filter)
 		return;
-	arpt_unregister_table(net, net->ipv4.arptable_filter, arpfilter_ops);
+	arpt_unregister_table(net, net->ipv4.arptable_filter);
 	net->ipv4.arptable_filter = NULL;
 }
 
 static struct pernet_operations arptable_filter_net_ops = {
 	.exit = arptable_filter_net_exit,
+	.pre_exit = arptable_filter_net_pre_exit,
 };
 
 static int __init arptable_filter_init(void)
-- 
2.20.1
Other recent patches touching these files
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help