[PATCH v1] vdpa: Complement vdpa_nl_policy for nlattr length check

Lin Ma
2023-07-23T08:05:23Z

The vdpa_nl_policy structure is used to validate the nlattr when parsing
the incoming nlmsg. It will ensure the attribute being described produces
a valid nlattr pointer in info->attrs before entering into each handler
in vdpa_nl_ops.

That is to say, the missing part in vdpa_nl_policy may lead to illegal
nlattr after parsing, which could lead to OOB read just like CVE-2023-3773.

This patch adds three missing nla_policy to avoid such bugs.

Fixes: 90fea5a800c3 ("vdpa: device feature provisioning")
Fixes: 13b00b135665 ("vdpa: Add support for querying vendor statistics")
Fixes: ad69dd0bf26b ("vdpa: Introduce query of device config layout")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
---
drivers/vdpa/vdpa.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 965e32529eb8..f2f654fd84e5 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -1247,8 +1247,11 @@ static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = {
[VDPA_ATTR_MGMTDEV_DEV_NAME] = { .type = NLA_STRING },
[VDPA_ATTR_DEV_NAME] = { .type = NLA_STRING },
[VDPA_ATTR_DEV_NET_CFG_MACADDR] = NLA_POLICY_ETH_ADDR,
+ [VDPA_ATTR_DEV_NET_CFG_MAX_VQP] = { .type = NLA_U16 },
/* virtio spec 1.1 section 5.1.4.1 for valid MTU range */
[VDPA_ATTR_DEV_NET_CFG_MTU] = NLA_POLICY_MIN(NLA_U16, 68),
+ [VDPA_ATTR_DEV_QUEUE_INDEX] = { .type = NLA_U32 },
+ [VDPA_ATTR_DEV_FEATURES] = { .type = NLA_U64 },
};

static const struct genl_ops vdpa_nl_ops[] = {
--
2.17.1