[PATCH] nfc: Fix potential resource leaks

Miaoqian Lin
2022-12-20T13:46:37Z

nfc_get_device() take reference for the device, add missing
nfc_put_device() to release it when not need anymore.
Also fix the style warnning by use error EOPNOTSUPP instead of
ENOTSUPP.

Fixes: 5ce3f32b5264 ("NFC: netlink: SE API implementation")
Fixes: 29e76924cf08 ("nfc: netlink: Add capability to reply to vendor_cmd with data")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
net/nfc/netlink.c | 51 ++++++++++++++++++++++++++++++++++-------------
1 file changed, 37 insertions(+), 14 deletions(-)

diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index 9d91087b9399..d081beaf4828 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -1497,6 +1497,7 @@ static int nfc_genl_se_io(struct sk_buff *skb, struct genl_info *info)
u32 dev_idx, se_idx;
u8 *apdu;
size_t apdu_len;
+ int error;

if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
!info->attrs[NFC_ATTR_SE_INDEX] ||
@@ -1510,25 +1511,37 @@ static int nfc_genl_se_io(struct sk_buff *skb, struct genl_info *info)
if (!dev)
return -ENODEV;

- if (!dev->ops || !dev->ops->se_io)
- return -ENOTSUPP;
+ if (!dev->ops || !dev->ops->se_io) {
+ error = -EOPNOTSUPP;
+ goto put_dev;
+ }

apdu_len = nla_len(info->attrs[NFC_ATTR_SE_APDU]);
- if (apdu_len == 0)
- return -EINVAL;
+ if (apdu_len == 0) {
+ error = -EINVAL;
+ goto put_dev;
+ }

apdu = nla_data(info->attrs[NFC_ATTR_SE_APDU]);
- if (!apdu)
- return -EINVAL;
+ if (!apdu) {
+ error = -EINVAL;
+ goto put_dev;
+ }

ctx = kzalloc(sizeof(struct se_io_ctx), GFP_KERNEL);
- if (!ctx)
- return -ENOMEM;
+ if (!ctx) {
+ error = -ENOMEM;
+ goto put_dev;
+ }

ctx->dev_idx = dev_idx;
ctx->se_idx = se_idx;

- return nfc_se_io(dev, se_idx, apdu, apdu_len, se_io_cb, ctx);
+ error = nfc_se_io(dev, se_idx, apdu, apdu_len, se_io_cb, ctx);
+
+put_dev:
+ nfc_put_device(dev);
+ return error;
}

static int nfc_genl_vendor_cmd(struct sk_buff *skb,
@@ -1551,14 +1564,20 @@ static int nfc_genl_vendor_cmd(struct sk_buff *skb,
subcmd = nla_get_u32(info->attrs[NFC_ATTR_VENDOR_SUBCMD]);

dev = nfc_get_device(dev_idx);
- if (!dev || !dev->vendor_cmds || !dev->n_vendor_cmds)
+ if (!dev)
return -ENODEV;
+ if (!dev->vendor_cmds || !dev->n_vendor_cmds) {
+ err = -ENODEV;
+ goto put_dev;
+ }

if (info->attrs[NFC_ATTR_VENDOR_DATA]) {
data = nla_data(info->attrs[NFC_ATTR_VENDOR_DATA]);
data_len = nla_len(info->attrs[NFC_ATTR_VENDOR_DATA]);
- if (data_len == 0)
- return -EINVAL;
+ if (data_len == 0) {
+ err = -EINVAL;
+ goto put_dev;
+ }
} else {
data = NULL;
data_len = 0;
@@ -1573,10 +1592,14 @@ static int nfc_genl_vendor_cmd(struct sk_buff *skb,
dev->cur_cmd_info = info;
err = cmd->doit(dev, data, data_len);
dev->cur_cmd_info = NULL;
- return err;
+ goto put_dev;
}

- return -EOPNOTSUPP;
+ err = -EOPNOTSUPP;
+
+put_dev:
+ nfc_put_device(dev);
+ return err;
}

/* message building helper */
--
2.25.1