diff options
author | Pablo Neira Ayuso <pablo@netfilter.org> | 2022-06-21 14:01:41 +0200 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2022-06-27 19:03:37 +0200 |
commit | 05907f10e235680cc7fb196810e4ad3215d5e648 (patch) | |
tree | 86ed120de0ef116f27b9aa350df0996f93c84c5e | |
parent | cb8092d70a6f5f01ec1490fce4d35efed3ed996c (diff) |
netfilter: nft_dynset: restore set element counter when failing to update
This patch fixes a race condition.
nft_rhash_update() might fail for two reasons:
- Element already exists in the hashtable.
- Another packet won race to insert an entry in the hashtable.
In both cases, new() has already bumped the counter via atomic_add_unless(),
therefore, decrement the set element counter.
Fixes: 22fe54d5fefc ("netfilter: nf_tables: add support for dynamic set updates")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
-rw-r--r-- | net/netfilter/nft_set_hash.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c index df40314de21f..76de6c8d9865 100644 --- a/net/netfilter/nft_set_hash.c +++ b/net/netfilter/nft_set_hash.c @@ -143,6 +143,7 @@ static bool nft_rhash_update(struct nft_set *set, const u32 *key, /* Another cpu may race to insert the element with the same key */ if (prev) { nft_set_elem_destroy(set, he, true); + atomic_dec(&set->nelems); he = prev; } @@ -152,6 +153,7 @@ out: err2: nft_set_elem_destroy(set, he, true); + atomic_dec(&set->nelems); err1: return false; } |