[PATCH stable v4.19] NFC: add necessary privilege flags in netlink layer

From: Lin Ma <[email protected]>

commit aedddb4e45b34426cfbfa84454b6f203712733c5 upstream.

The CAP_NET_ADMIN checks are needed to prevent attackers faking a
device under NCIUARTSETDRIVER and exploit privileged commands.

This patch add GENL_ADMIN_PERM flags in genl_ops to fulfill the check.
Except for commands like NFC_CMD_GET_DEVICE, NFC_CMD_GET_TARGET,
NFC_CMD_LLC_GET_PARAMS, and NFC_CMD_GET_SE, which are mainly information-
read operations.

Signed-off-by: Lin Ma <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
[krzysztof: context changes and backport]
Signed-off-by: Krzysztof Kozlowski <[email protected]>
---
 net/nfc/netlink.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index 4884e1987562..113250946e05 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -1682,31 +1682,37 @@ static const struct genl_ops nfc_genl_ops[] = {
 		.cmd = NFC_CMD_DEV_UP,
 		.doit = nfc_genl_dev_up,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_DEV_DOWN,
 		.doit = nfc_genl_dev_down,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_START_POLL,
 		.doit = nfc_genl_start_poll,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_STOP_POLL,
 		.doit = nfc_genl_stop_poll,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_DEP_LINK_UP,
 		.doit = nfc_genl_dep_link_up,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_DEP_LINK_DOWN,
 		.doit = nfc_genl_dep_link_down,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_GET_TARGET,
@@ -1723,26 +1729,31 @@ static const struct genl_ops nfc_genl_ops[] = {
 		.cmd = NFC_CMD_LLC_SET_PARAMS,
 		.doit = nfc_genl_llc_set_params,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_LLC_SDREQ,
 		.doit = nfc_genl_llc_sdreq,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_FW_DOWNLOAD,
 		.doit = nfc_genl_fw_download,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_ENABLE_SE,
 		.doit = nfc_genl_enable_se,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_DISABLE_SE,
 		.doit = nfc_genl_disable_se,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_GET_SE,
@@ -1754,21 +1765,25 @@ static const struct genl_ops nfc_genl_ops[] = {
 		.cmd = NFC_CMD_SE_IO,
 		.doit = nfc_genl_se_io,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_ACTIVATE_TARGET,
 		.doit = nfc_genl_activate_target,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_VENDOR,
 		.doit = nfc_genl_vendor_cmd,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NFC_CMD_DEACTIVATE_TARGET,
 		.doit = nfc_genl_deactivate_target,
 		.policy = nfc_genl_policy,
+		.flags = GENL_ADMIN_PERM,
 	},
 };
 
-- 
2.32.0