[PATCH 5.15 081/177] netfilter: nft_set_rbtree: overlap detection with element re-addition after deletion

Greg Kroah-Hartman
2022-05-04T17:13:18Z

From: Pablo Neira Ayuso <pablo@netfilter.org>

[ Upstream commit babc3dc9524f0bcb5a0ec61f3c3639b11508fad6 ]

This patch fixes spurious EEXIST errors.

Extend d2df92e98a34 ("netfilter: nft_set_rbtree: handle element
re-addition after deletion") to deal with elements with same end flags
in the same transation.

Reset the overlap flag as described by 7c84d41416d8 ("netfilter:
nft_set_rbtree: Detect partial overlaps on insertion").

Fixes: 7c84d41416d8 ("netfilter: nft_set_rbtree: Detect partial overlaps on insertion")
Fixes: d2df92e98a34 ("netfilter: nft_set_rbtree: handle element re-addition after deletion")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nft_set_rbtree.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index d600a566da32..7325bee7d144 100644
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -349,7 +349,11 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
*ext = &rbe->ext;
return -EEXIST;
} else {
- p = &parent->rb_left;
+ overlap = false;
+ if (nft_rbtree_interval_end(rbe))
+ p = &parent->rb_left;
+ else
+ p = &parent->rb_right;
}
}

--
2.35.1