Thread (16 messages) 16 messages, 2 authors, 2016-11-10
STALE3547d
Revisions (202)
  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 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 [diff vs 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. v1 [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. v1 [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. v1 [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. v1 [diff vs current]
  122. v1 [diff vs current]
  123. v2 [diff vs current]
  124. v1 [diff vs current]
  125. v1 [diff vs current]
  126. v1 [diff vs current]
  127. v1 [diff vs current]
  128. v1 [diff vs current]
  129. v1 [diff vs current]
  130. v1 [diff vs current]
  131. v1 [diff vs current]
  132. v1 [diff vs current]
  133. v1 [diff vs current]
  134. v1 [diff vs current]
  135. v1 [diff vs current]
  136. v1 [diff vs current]
  137. v1 [diff vs current]
  138. v1 [diff vs current]
  139. v1 [diff vs current]
  140. v1 [diff vs current]
  141. v1 [diff vs current]
  142. v1 [diff vs current]
  143. v1 [diff vs current]
  144. v1 [diff vs current]
  145. v1 [diff vs current]
  146. v1 [diff vs current]
  147. v1 [diff vs current]
  148. v1 [diff vs current]
  149. v1 [diff vs current]
  150. v1 [diff vs current]
  151. v1 [diff vs current]
  152. v1 [diff vs current]
  153. v1 [diff vs current]
  154. v1 [diff vs current]
  155. v1 [diff vs current]
  156. v1 [diff vs current]
  157. v1 [diff vs current]
  158. v1 [diff vs current]
  159. v1 [diff vs current]
  160. v2 [diff vs current]
  161. v1 [diff vs current]
  162. v1 [diff vs current]
  163. v1 [diff vs current]
  164. v2 [diff vs current]
  165. v1 [diff vs current]
  166. v1 [diff vs current]
  167. v1 [diff vs current]
  168. v1 [diff vs current]
  169. v2 [diff vs current]
  170. v1 [diff vs current]
  171. v1 [diff vs current]
  172. v1 [diff vs current]
  173. v1 [diff vs current]
  174. v3 [diff vs current]
  175. v1 [diff vs current]
  176. v1 [diff vs current]
  177. v1 [diff vs current]
  178. v1 [diff vs current]
  179. v1 [diff vs current]
  180. v2 [diff vs current]
  181. v1 [diff vs current]
  182. v1 [diff vs current]
  183. v1 [diff vs current]
  184. v1 [diff vs current]
  185. v1 [diff vs current]
  186. v2 [diff vs current]
  187. v1 [diff vs current]
  188. v1 [diff vs current]
  189. v1 [diff vs current]
  190. v1 [diff vs current]
  191. v1 [diff vs current]
  192. v1 [diff vs current]
  193. v1 [diff vs current]
  194. v2 [diff vs current]
  195. v1 [diff vs current]
  196. v2 [diff vs current]
  197. v1 [diff vs current]
  198. v1 [diff vs current]
  199. v1 [diff vs current]
  200. v1 [diff vs current]
  201. v2 [diff vs current]
  202. v1 [diff vs current]

[PATCH 03/14] netfilter: nf_tables: fix race when create new element in dynset

From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2016-11-10 00:24:05
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: Liping Zhang <redacted>

Packets may race when create the new element in nft_hash_update:
       CPU0                 CPU1
  lookup_fast - fail     lookup_fast - fail
       new - ok             new - ok
     insert - ok         insert - fail(EEXIST)

So when race happened, we reuse the existing element. Otherwise,
these *racing* packets will not be handled properly.

Fixes: 22fe54d5fefc ("netfilter: nf_tables: add support for dynamic set updates")
Signed-off-by: Liping Zhang <redacted>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_set_hash.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index 88d9fc8343e7..a3dface3e6e6 100644
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c
@@ -98,7 +98,7 @@ static bool nft_hash_update(struct nft_set *set, const u32 *key,
 			    const struct nft_set_ext **ext)
 {
 	struct nft_hash *priv = nft_set_priv(set);
-	struct nft_hash_elem *he;
+	struct nft_hash_elem *he, *prev;
 	struct nft_hash_cmp_arg arg = {
 		.genmask = NFT_GENMASK_ANY,
 		.set	 = set,
@@ -112,9 +112,18 @@ static bool nft_hash_update(struct nft_set *set, const u32 *key,
 	he = new(set, expr, regs);
 	if (he == NULL)
 		goto err1;
-	if (rhashtable_lookup_insert_key(&priv->ht, &arg, &he->node,
-					 nft_hash_params))
+
+	prev = rhashtable_lookup_get_insert_key(&priv->ht, &arg, &he->node,
+						nft_hash_params);
+	if (IS_ERR(prev))
 		goto err2;
+
+	/* Another cpu may race to insert the element with the same key */
+	if (prev) {
+		nft_set_elem_destroy(set, he, true);
+		he = prev;
+	}
+
 out:
 	*ext = &he->ext;
 	return true;
-- 
2.1.4
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