[PATCH 1/4] vdpa: Add features attr to vdpa_nl_policy for nlattr length check

[Dragos Tatulea]

From: Lin Ma <linma@xxxxxxxxxx>

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 the missing nla_policy for vdpa features attr to avoid
such bugs.

Fixes: 90fea5a800c3 ("vdpa: device feature provisioning")
Signed-off-by: Lin Ma <linma@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
 drivers/vdpa/vdpa.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 965e32529eb8..3ad355a2208a 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -1249,6 +1249,7 @@ static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = {
 	[VDPA_ATTR_DEV_NET_CFG_MACADDR] = NLA_POLICY_ETH_ADDR,
 	/* 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_FEATURES] = { .type = NLA_U64 },
 };
 
 static const struct genl_ops vdpa_nl_ops[] = {
-- 
2.41.0