[PATCH 4.14 116/164] rsi: fix memory leak on buf and usb_reg_buf

From: Greg Kroah-Hartman
Date: Tue Dec 12 2017 - 08:47:45 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

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


[ Upstream commit d35ef8f846c72d84bfccf239c248c84f79c3a7e8 ]

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>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/wireless/rsi/rsi_91x_usb.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

--- 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_d
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_
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;