From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
[ Upstream commit 8971ee8b087750a23f3cd4dc55bff2d0303fd267 ]
The private helper data size cannot be updated. However, updates that
contain NFCTH_PRIV_DATA_LEN might bogusly hit EBUSY even if the size is
the same.
Fixes: 12f7a505331e ("netfilter: add user-space connection tracking helper infrastructure")
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/netfilter/nfnetlink_cthelper.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c
index 0f94fce1d3ed..04a12a264cf7 100644
--- a/net/netfilter/nfnetlink_cthelper.c
+++ b/net/netfilter/nfnetlink_cthelper.c
@@ -380,10 +380,14 @@ static int
nfnl_cthelper_update(const struct nlattr * const tb[],
struct nf_conntrack_helper *helper)
{
+ u32 size;
int ret;
- if (tb[NFCTH_PRIV_DATA_LEN])
- return -EBUSY;
+ if (tb[NFCTH_PRIV_DATA_LEN]) {
+ size = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
+ if (size != helper->data_len)
+ return -EBUSY;
+ }
if (tb[NFCTH_POLICY]) {
ret = nfnl_cthelper_update_policy(helper, tb[NFCTH_POLICY]);
--
2.30.2
