From: Pablo Neira Ayuso pablo@netfilter.org
stable inclusion from linux-4.19.194 commit 8aed10cd9497933ebe3fc0afe8d8ddc1af8b0d48
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[ 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@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- 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 ddcb1b6074745..c8b0f1122c44d 100644 --- a/net/netfilter/nfnetlink_cthelper.c +++ b/net/netfilter/nfnetlink_cthelper.c @@ -381,10 +381,14 @@ 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]);