2021-11-02 08:13:01

by Lin Ma

Subject: [PATCH] NFC: add necessary privilege flags in netlink layer

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]>
---
net/nfc/netlink.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index 49089c50872e..334f63c9529e 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -1664,31 +1664,37 @@ static const struct genl_ops nfc_genl_ops[] = {
.cmd = NFC_CMD_DEV_UP,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_dev_up,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_DEV_DOWN,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_dev_down,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_START_POLL,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_start_poll,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_STOP_POLL,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_stop_poll,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_DEP_LINK_UP,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_dep_link_up,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_DEP_LINK_DOWN,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_dep_link_down,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_GET_TARGET,
@@ -1706,26 +1712,31 @@ static const struct genl_ops nfc_genl_ops[] = {
.cmd = NFC_CMD_LLC_SET_PARAMS,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_llc_set_params,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_LLC_SDREQ,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_llc_sdreq,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_FW_DOWNLOAD,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_fw_download,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_ENABLE_SE,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_enable_se,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_DISABLE_SE,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_disable_se,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_GET_SE,
@@ -1737,21 +1748,25 @@ static const struct genl_ops nfc_genl_ops[] = {
.cmd = NFC_CMD_SE_IO,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_se_io,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_ACTIVATE_TARGET,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_activate_target,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_VENDOR,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_vendor_cmd,
+ .flags = GENL_ADMIN_PERM,
},
{
.cmd = NFC_CMD_DEACTIVATE_TARGET,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = nfc_genl_deactivate_target,
+ .flags = GENL_ADMIN_PERM,
},
};

--
2.33.1

2021-11-03 11:23:03

by patchwork-bot+netdevbpf

Subject: Re: [PATCH] NFC: add necessary privilege flags in netlink layer

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <[email protected]>:

On Tue, 2 Nov 2021 16:10:21 +0800 you wrote:
> 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.
>
> [...]

Here is the summary with links:
- NFC: add necessary privilege flags in netlink layer
https://git.kernel.org/netdev/net/c/aedddb4e45b3

You are awesome, thank you!
--
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