netdev - [nf PATCH] netfilter: conntrack: helper: Replace -EEXIST by -EBUSY

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20250818112220.26641-1-phil@nwl.cc>
Date: Mon, 18 Aug 2025 13:22:20 +0200
From: Phil Sutter <phil@....cc>
To: Pablo Neira Ayuso <pablo@...filter.org>
Cc: netfilter-devel@...r.kernel.org,
	Yi Chen <yiche@...hat.com>,
	linux-modules@...r.kernel.org,
	netdev@...r.kernel.org,
	Christophe Leroy <christophe.leroy@...roup.eu>
Subject: [nf PATCH] netfilter: conntrack: helper: Replace -EEXIST by -EBUSY

The helper registration return value is passed-through by module_init
callbacks which modprobe confuses with the harmless -EEXIST returned
when trying to load an already loaded module.

Make sure modprobe fails so users notice their helper has not been
registered and won't work.

Suggested-by: Christophe Leroy <christophe.leroy@...roup.eu>
Fixes: 12f7a505331e ("netfilter: add user-space connection tracking helper infrastructure")
Signed-off-by: Phil Sutter <phil@....cc>
---
 net/netfilter/nf_conntrack_helper.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index 4ed5878cb25b..ceb48c3ca0a4 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -368,7 +368,7 @@ int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
 			    (cur->tuple.src.l3num == NFPROTO_UNSPEC ||
 			     cur->tuple.src.l3num == me->tuple.src.l3num) &&
 			    cur->tuple.dst.protonum == me->tuple.dst.protonum) {
-				ret = -EEXIST;
+				ret = -EBUSY;
 				goto out;
 			}
 		}
@@ -379,7 +379,7 @@ int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
 		hlist_for_each_entry(cur, &nf_ct_helper_hash[h], hnode) {
 			if (nf_ct_tuple_src_mask_cmp(&cur->tuple, &me->tuple,
 						     &mask)) {
-				ret = -EEXIST;
+				ret = -EBUSY;
 				goto out;
 			}
 		}
-- 
2.49.0