Thread (8 messages) read the whole thread 8 messages, 2 authors, 2015-12-14
STALE3885d

Revision v1 of 112 in this series.

Revisions (112)
  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 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. v2 [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. v2 [diff vs current]
  89. v1 [diff vs current]
  90. v1 [diff vs current]
  91. v1 [diff vs current]
  92. v2 [diff vs current]
  93. v1 [diff vs current]
  94. v1 [diff vs current]
  95. v1 [diff vs current]
  96. v2 [diff vs current]
  97. v3 [diff vs current]
  98. v1 [diff vs current]
  99. v1 [diff vs current]
  100. v2 [diff vs current]
  101. v1 [diff vs current]
  102. v1 [diff vs current]
  103. v1 [diff vs current]
  104. v2 [diff vs current]
  105. v1 [diff vs current]
  106. v2 [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]

[PATCH 6/6] netfilter: nf_tables: use reverse traversal commit_list in nf_tables_abort

From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2015-12-14 11:25:46
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: Xin Long <lucien.xin@gmail.com>

When we use 'nft -f' to submit rules, it will build multiple rules into
one netlink skb to send to kernel, kernel will process them one by one.
meanwhile, it add the trans into commit_list to record every commit.
if one of them's return value is -EAGAIN, status |= NFNL_BATCH_REPLAY
will be marked. after all the process is done. it will roll back all the
commits.

now kernel use list_add_tail to add trans to commit, and use
list_for_each_entry_safe to roll back. which means the order of adding
and rollback is the same. that will cause some cases cannot work well,
even trigger call trace, like:

1. add a set into table foo  [return -EAGAIN]:
   commit_list = 'add set trans'
2. del foo:
   commit_list = 'add set trans' -> 'del set trans' -> 'del tab trans'
then nf_tables_abort will be called to roll back:
firstly process 'add set trans':
                   case NFT_MSG_NEWSET:
                        trans->ctx.table->use--;
                        list_del_rcu(&nft_trans_set(trans)->list);

  it will del the set from the table foo, but it has removed when del
  table foo [step 2], then the kernel will panic.

the right order of rollback should be:
  'del tab trans' -> 'del set trans' -> 'add set trans'.
which is opposite with commit_list order.

so fix it by rolling back commits with reverse order in nf_tables_abort.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index f1002dc..2cb429d 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4024,7 +4024,8 @@ static int nf_tables_abort(struct sk_buff *skb)
 	struct nft_trans *trans, *next;
 	struct nft_trans_elem *te;
 
-	list_for_each_entry_safe(trans, next, &net->nft.commit_list, list) {
+	list_for_each_entry_safe_reverse(trans, next, &net->nft.commit_list,
+					 list) {
 		switch (trans->msg_type) {
 		case NFT_MSG_NEWTABLE:
 			if (nft_trans_table_update(trans)) {
-- 
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