From: Pablo Neira Ayuso <pablo@netfilter.org> stable inclusion from stable-v5.10.129 commit 91d3bb82c43e8dfb68ef9e0d61d7bf27b0c7b5b0 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5YNDQ Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- 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> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> --- net/netfilter/nft_set_hash.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c index 858c8d4d659a..a5cfb321ae23 100644 --- a/net/netfilter/nft_set_hash.c +++ b/net/netfilter/nft_set_hash.c @@ -142,6 +142,7 @@ 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; } @@ -151,6 +152,7 @@ static bool nft_rhash_update(struct nft_set *set, const u32 *key, err2: nft_set_elem_destroy(set, he, true); + atomic_dec(&set->nelems); err1: return false; } -- 2.20.1