[PATCH] rsi: fix memory leak on buf and usb_reg_buf

From: Colin King
Date: Thu Nov 16 2017 - 12:39:40 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

In the cases where len is too long, the error return path fails to
kfree allocated buffers buf and usb_reg_buf. The simplest fix is to
perform the sanity check on len before the allocations to avoid having
to do the kfree'ing in the first place.

Detected by CoverityScan, CID#1452258,1452259 ("Resource Leak")

Fixes: 59f73e2ae185 ("rsi: check length before USB read/write register")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/net/wireless/rsi/rsi_91x_usb.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/rsi/rsi_91x_usb.c b/drivers/net/wireless/rsi/rsi_91x_usb.c
index 08730227cd18..8f8443833348 100644
--- a/drivers/net/wireless/rsi/rsi_91x_usb.c
+++ b/drivers/net/wireless/rsi/rsi_91x_usb.c
@@ -162,13 +162,13 @@ static int rsi_usb_reg_read(struct usb_device *usbdev,
u8 *buf;
int status = -ENOMEM;

+ if (len > RSI_USB_CTRL_BUF_SIZE)
+ return -EINVAL;
+
buf = kmalloc(RSI_USB_CTRL_BUF_SIZE, GFP_KERNEL);
if (!buf)
return status;

- if (len > RSI_USB_CTRL_BUF_SIZE)
- return -EINVAL;
-
status = usb_control_msg(usbdev,
usb_rcvctrlpipe(usbdev, 0),
USB_VENDOR_REGISTER_READ,
@@ -207,13 +207,13 @@ static int rsi_usb_reg_write(struct usb_device *usbdev,
u8 *usb_reg_buf;
int status = -ENOMEM;

+ if (len > RSI_USB_CTRL_BUF_SIZE)
+ return -EINVAL;
+
usb_reg_buf = kmalloc(RSI_USB_CTRL_BUF_SIZE, GFP_KERNEL);
if (!usb_reg_buf)
return status;

- if (len > RSI_USB_CTRL_BUF_SIZE)
- return -EINVAL;
-
usb_reg_buf[0] = (value & 0x00ff);
usb_reg_buf[1] = (value & 0xff00) >> 8;
usb_reg_buf[2] = 0x0;
--
2.14.1