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| author | Xin Long <lucien.xin@gmail.com> | 2015-12-07 18:48:07 +0800 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2015-12-13 22:47:32 +0100 |
| commit | a907e36d54e0ff836e55e04531be201bf6b4d8c8 (patch) | |
| tree | e9f101437b20302966b7f5177691a9dc9800d2cb /net | |
| parent | d3340b79ec8222d20453b1e7f261b017d1d09dc9 (diff) | |
| download | linux-a907e36d54e0ff836e55e04531be201bf6b4d8c8.tar.gz linux-a907e36d54e0ff836e55e04531be201bf6b4d8c8.tar.bz2 linux-a907e36d54e0ff836e55e04531be201bf6b4d8c8.zip | |
netfilter: nf_tables: use reverse traversal commit_list in nf_tables_abort
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nf_tables_api.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index f1002dcfa1c9..2cb429d34c03 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)) { |