netfilter: nft_set_rbtree: overlap detection with element re-addition after deletion

stable inclusion
from stable-v5.10.114
commit 6ac03e6ddde97faa4b93097efda89fdbf26f2737
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5IY1V

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6ac03e6ddde97faa4b93097efda89fdbf26f2737

--------------------------------

[ Upstream commit babc3dc9 ]

This patch fixes spurious EEXIST errors.

Extend d2df92e9 ("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 7c84d414 ("netfilter:
nft_set_rbtree: Detect partial overlaps on insertion").

Fixes: 7c84d414 ("netfilter: nft_set_rbtree: Detect partial overlaps on insertion")
Fixes: d2df92e9 ("netfilter: nft_set_rbtree: handle element re-addition after deletion")
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Reviewed-by: NStefano Brivio <sbrivio@redhat.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

net/netfilter/nft_set_rbtree.c

@@ -348,7 +348,11 @@ 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;
 			}
 		}