2023-08-01 07:35:40

by Stanley Chang[昌育德]

Subject: [PATCH usb-next] phy: realtek: usb: add the error handler for nvmem_cell_read

There are following smatch warning:
drivers/phy/realtek/phy-rtk-usb2.c:901 get_phy_data_by_efuse()
error: 'buf' dereferencing possible ERR_PTR()
drivers/phy/realtek/phy-rtk-usb2.c:942 get_phy_data_by_efuse()
error: 'buf' dereferencing possible ERR_PTR()

drivers/phy/realtek/phy-rtk-usb3.c:460
get_phy_data_by_efuse() error: 'buf' dereferencing possible ERR_PTR()

The nvmem_cell_read may fail to read. So, driver must handle failure cases.

Fixes: 134e6d25f6bd ("phy: realtek: usb: Add driver for the Realtek SoC USB 2.0 PHY")
Fixes: adda6e82a7de ("phy: realtek: usb: Add driver for the Realtek SoC USB 3.0 PHY")
Reported-by: Dan Carpenter <[email protected]>
Closes: https://lore.kernel.org/linux-phy/[email protected]/
Signed-off-by: Stanley Chang <[email protected]>
---
drivers/phy/realtek/phy-rtk-usb2.c | 14 ++++++++------
drivers/phy/realtek/phy-rtk-usb3.c | 7 ++++---
2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/phy/realtek/phy-rtk-usb2.c b/drivers/phy/realtek/phy-rtk-usb2.c
index ed47a1ce5d9c..5e7ee060b404 100644
--- a/drivers/phy/realtek/phy-rtk-usb2.c
+++ b/drivers/phy/realtek/phy-rtk-usb2.c
@@ -898,9 +898,10 @@ static int get_phy_data_by_efuse(struct rtk_phy *rtk_phy,
size_t buf_size;

buf = nvmem_cell_read(cell, &buf_size);
- value = buf[0] & phy_cfg->dc_driving_mask;
-
- kfree(buf);
+ if (!IS_ERR(buf)) {
+ value = buf[0] & phy_cfg->dc_driving_mask;
+ kfree(buf);
+ }
nvmem_cell_put(cell);
}

@@ -939,9 +940,10 @@ static int get_phy_data_by_efuse(struct rtk_phy *rtk_phy,
size_t buf_size;

buf = nvmem_cell_read(cell, &buf_size);
- value = buf[0] & phy_cfg->dc_disconnect_mask;
-
- kfree(buf);
+ if (!IS_ERR(buf)) {
+ value = buf[0] & phy_cfg->dc_disconnect_mask;
+ kfree(buf);
+ }
nvmem_cell_put(cell);
}

diff --git a/drivers/phy/realtek/phy-rtk-usb3.c b/drivers/phy/realtek/phy-rtk-usb3.c
index 6050f1ef4f6b..7881f908aade 100644
--- a/drivers/phy/realtek/phy-rtk-usb3.c
+++ b/drivers/phy/realtek/phy-rtk-usb3.c
@@ -457,9 +457,10 @@ static int get_phy_data_by_efuse(struct rtk_phy *rtk_phy,
size_t buf_size;

buf = nvmem_cell_read(cell, &buf_size);
- value = buf[0] & USB_U3_TX_LFPS_SWING_TRIM_MASK;
-
- kfree(buf);
+ if (!IS_ERR(buf)) {
+ value = buf[0] & USB_U3_TX_LFPS_SWING_TRIM_MASK;
+ kfree(buf);
+ }
nvmem_cell_put(cell);
}

--
2.34.1