[SRU Jammy, OEM-6.1, Lunar, Mantic 1/1] netfilter: nft_set_pipapo: skip inactive elements during set walk

[Thadeu Lima de Souza Cascardo]

From: Florian Westphal <fw at strlen.de>

Otherwise set elements can be deactivated twice which will cause a crash.

Reported-by: Xingyuan Mo <hdthky0 at gmail.com>
Fixes: 3c4287f62044 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Signed-off-by: Florian Westphal <fw at strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo at netfilter.org>
(backported from commit 317eb9685095678f2c9f5a8189de698c5354316a)
[cascardo: context conflict due to missing 0e1ea651c9717ddcd8e0648d8468477a31867b0a]
CVE-2023-6817
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo at canonical.com>
---
 net/netfilter/nft_set_pipapo.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index c0dcc40de358..3ff31043f714 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -2041,6 +2041,9 @@ static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set,
 
 		e = f->mt[r].e;
 
+		if (!nft_set_elem_active(&e->ext, iter->genmask))
+			goto cont;
+
 		elem.priv = e;
 
 		iter->err = iter->fn(ctx, set, iter, &elem);
-- 
2.34.1