[PATCH nf] netfilter: ipset: do not update comments from kernel-side adds

[PATCH nf] netfilter: ipset: do not update comments from kernel-side adds

[Florian Westphal]

'Fixes' commit stopped calling ip_set_init_comment() for hash types
from kernel-side-adds (xtables .. -j SET).  ip_set_init_comment() says:

   "The kadt functions don't use the comment extensions in any way."

But bitmap set type calls the function from kadt cb too.

While this appears to be safe (serialized via the set spinlock), it seems
better to not call the init function either, least of all to keep
behaviour consistent.

ip_set_list calls ip_set_init_comment() only from uadt cb, it can be
kept as-is.

This was triggered by yet another LLM review, hinting that the existing
rcu_dereference_protected() cannot be downgraded to only check if the
nfnl mutex is held.

Fixes: f30415929be8 ("netfilter: ipset: do not update comments from kernel-side hash adds")
Signed-off-by: Florian Westphal <fw@strlen.de>
---
 net/netfilter/ipset/ip_set_bitmap_gen.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/ipset/ip_set_bitmap_gen.h b/net/netfilter/ipset/ip_set_bitmap_gen.h
index d6a7e6604542..ae376fa3e7a3 100644
--- a/net/netfilter/ipset/ip_set_bitmap_gen.h
+++ b/net/netfilter/ipset/ip_set_bitmap_gen.h
@@ -159,7 +159,7 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext,
 
 	if (SET_WITH_COUNTER(set))
 		ip_set_init_counter(ext_counter(x, set), ext);
-	if (SET_WITH_COMMENT(set))
+	if (SET_WITH_COMMENT(set) && !ext->target)
 		ip_set_init_comment(set, ext_comment(x, set), ext);
 	if (SET_WITH_SKBINFO(set))
 		ip_set_init_skbinfo(ext_skbinfo(x, set), ext);
-- 
2.55.0