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author | Pablo Neira Ayuso <pablo@netfilter.org> | 2022-06-21 14:01:41 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-07 17:53:27 +0200 |
commit | 031561caa38a67cbf3084c38b8ebed52bbc1e602 (patch) | |
tree | 361418a63ef0c0311b475907584ab17945bc8656 /net/netfilter | |
parent | a6c5c65f4c371f89bb60b3b044f136f9131afd8a (diff) | |
download | linux-stable-031561caa38a67cbf3084c38b8ebed52bbc1e602.tar.gz linux-stable-031561caa38a67cbf3084c38b8ebed52bbc1e602.tar.bz2 linux-stable-031561caa38a67cbf3084c38b8ebed52bbc1e602.zip |
netfilter: nft_dynset: restore set element counter when failing to update
commit 05907f10e235680cc7fb196810e4ad3215d5e648 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/netfilter')
-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; } |