Dynamic static allocation is evil, as Kernel stack is too low, and
compilation complains about it on some archs:
drivers/media/usb/dvb-usb/cxusb.c:209:1: warning: 'cxusb_i2c_xfer' uses dynamic stack allocation [enabled by default]
drivers/media/usb/dvb-usb/cxusb.c:69:1: warning: 'cxusb_ctrl_msg' uses dynamic stack allocation [enabled by default]
Instead, let's enforce a limit for the buffer to be the max size of
a control URB payload data (80 bytes).
Signed-off-by: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx>
Cc: Michael Krufky <mkrufky@xxxxxxxxxxx>
---
drivers/media/usb/dvb-usb/cxusb.c | 38 ++++++++++++++++++++++++++++++++++----
1 file changed, 34 insertions(+), 4 deletions(-)
diff --git a/drivers/media/usb/dvb-usb/cxusb.c b/drivers/media/usb/dvb-usb/cxusb.c
index 3940bb0f9ef6..7d21def6b145 100644
--- a/drivers/media/usb/dvb-usb/cxusb.c
+++ b/drivers/media/usb/dvb-usb/cxusb.c
@@ -57,7 +57,14 @@ static int cxusb_ctrl_msg(struct dvb_usb_device *d,
u8 cmd, u8 *wbuf, int wlen, u8 *rbuf, int rlen)
{
int wo = (rbuf == NULL || rlen == 0); /* write-only */
- u8 sndbuf[1+wlen];
+ u8 sndbuf[80];
+
+ if (1 + wlen > sizeof(sndbuf)) {
+ warn("i2c wr: len=%d is too big!\n",
+ wlen);
+ return -EREMOTEIO;
+ }
+
memset(sndbuf, 0, 1+wlen);
sndbuf[0] = cmd;
@@ -158,7 +165,13 @@ static int cxusb_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
if (msg[i].flags & I2C_M_RD) {
/* read only */
- u8 obuf[3], ibuf[1+msg[i].len];
+ u8 obuf[3], ibuf[80];
+
+ if (1 + msg[i].len > sizeof(ibuf)) {
+ warn("i2c rd: len=%d is too big!\n",
+ msg[i].len);
+ return -EREMOTEIO;
+ }
obuf[0] = 0;
obuf[1] = msg[i].len;
obuf[2] = msg[i].addr;
@@ -172,7 +185,18 @@ static int cxusb_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
} else if (i+1 < num && (msg[i+1].flags & I2C_M_RD) &&
msg[i].addr == msg[i+1].addr) {
/* write to then read from same address */
- u8 obuf[3+msg[i].len], ibuf[1+msg[i+1].len];
+ u8 obuf[80], ibuf[80];
+
+ if (3 + msg[i].len > sizeof(obuf)) {
+ warn("i2c wr: len=%d is too big!\n",
+ msg[i].len);
+ return -EREMOTEIO;
+ }
+ if (1 + msg[i + 1].len > sizeof(ibuf)) {
+ warn("i2c rd: len=%d is too big!\n",
+ msg[i + 1].len);
+ return -EREMOTEIO;
+ }
obuf[0] = msg[i].len;
obuf[1] = msg[i+1].len;
obuf[2] = msg[i].addr;
@@ -191,7 +215,13 @@ static int cxusb_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
i++;
} else {
/* write only */
- u8 obuf[2+msg[i].len], ibuf;
+ u8 obuf[80], ibuf;
+
+ if (2 + msg[i].len > sizeof(obuf)) {
+ warn("i2c wr: len=%d is too big!\n",
+ msg[i].len);
+ return -EREMOTEIO;
+ }
obuf[0] = msg[i].addr;
obuf[1] = msg[i].len;
memcpy(&obuf[2], msg[i].buf, msg[i].len);
--
1.8.3.1
--
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