[PATCH AUTOSEL 6.2 30/53] netfilter: nf_tables: NULL pointer dereference in nf_tables_updobj()

Sasha Levin
2023-02-26T14:50:35Z

From: Alok Tiwari <alok.a.tiwari@oracle.com>

[ Upstream commit dac7f50a45216d652887fb92d6cd3b7ca7f006ea ]

static analyzer detect null pointer dereference case for 'type'
function __nft_obj_type_get() can return NULL value which require to handle
if type is NULL pointer return -ENOENT.

This is a theoretical issue, since an existing object has a type, but
better add this failsafe check.

Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nf_tables_api.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 8c09e4d12ac1e..fc8256b00b320 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6999,6 +6999,9 @@ static int nf_tables_newobj(struct sk_buff *skb, const struct nfnl_info *info,
return -EOPNOTSUPP;

type = __nft_obj_type_get(objtype);
+ if (WARN_ON_ONCE(!type))
+ return -ENOENT;
+
nft_ctx_init(&ctx, net, skb, info->nlh, family, table, NULL, nla);

return nf_tables_updobj(&ctx, type, nla[NFTA_OBJ_DATA], obj);
--
2.39.0