[PATCH net 06/14] netfilter: xt_CT: fix usersize for v1 and v2 revision

Pablo Neira Ayuso
2026-05-01T12:22:52Z

From: Florian Westphal <fw@strlen.de>

While resurrecting the conntrack-tool test cases I found following bug:
In:
iptables -I OUTPUT -t raw -p 13 -j CT --timeout test-generic
Out:
[0:0] -A OUTPUT -p 13 -j CT --timeout test

Data after first four bytes of the timeout policy name is never
copied to userspace because its treated as kernel-only.

Fixes: ec2318904965 ("xtables: extend matches and targets with .usersize")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/xt_CT.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/xt_CT.c b/net/netfilter/xt_CT.c
index 498f5871c84a..d2aeacf94230 100644
--- a/net/netfilter/xt_CT.c
+++ b/net/netfilter/xt_CT.c
@@ -354,7 +354,7 @@ static struct xt_target xt_ct_tg_reg[] __read_mostly = {
.family = NFPROTO_IPV4,
.revision = 1,
.targetsize = sizeof(struct xt_ct_target_info_v1),
- .usersize = offsetof(struct xt_ct_target_info, ct),
+ .usersize = offsetof(struct xt_ct_target_info_v1, ct),
.checkentry = xt_ct_tg_check_v1,
.destroy = xt_ct_tg_destroy_v1,
.target = xt_ct_target_v1,
@@ -366,7 +366,7 @@ static struct xt_target xt_ct_tg_reg[] __read_mostly = {
.family = NFPROTO_IPV4,
.revision = 2,
.targetsize = sizeof(struct xt_ct_target_info_v1),
- .usersize = offsetof(struct xt_ct_target_info, ct),
+ .usersize = offsetof(struct xt_ct_target_info_v1, ct),
.checkentry = xt_ct_tg_check_v2,
.destroy = xt_ct_tg_destroy_v1,
.target = xt_ct_target_v1,
@@ -398,7 +398,7 @@ static struct xt_target xt_ct_tg_reg[] __read_mostly = {
.family = NFPROTO_IPV6,
.revision = 1,
.targetsize = sizeof(struct xt_ct_target_info_v1),
- .usersize = offsetof(struct xt_ct_target_info, ct),
+ .usersize = offsetof(struct xt_ct_target_info_v1, ct),
.checkentry = xt_ct_tg_check_v1,
.destroy = xt_ct_tg_destroy_v1,
.target = xt_ct_target_v1,
@@ -410,7 +410,7 @@ static struct xt_target xt_ct_tg_reg[] __read_mostly = {
.family = NFPROTO_IPV6,
.revision = 2,
.targetsize = sizeof(struct xt_ct_target_info_v1),
- .usersize = offsetof(struct xt_ct_target_info, ct),
+ .usersize = offsetof(struct xt_ct_target_info_v1, ct),
.checkentry = xt_ct_tg_check_v2,
.destroy = xt_ct_tg_destroy_v1,
.target = xt_ct_target_v1,
--
2.47.3