3.2.92-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx> commit 0065a79a8698a953e4b201c5fce8db8940530578 upstream. Dynamic static allocation is evil, as Kernel stack is too low, and compilation complains about it on some archs: drivers/media/usb/dvb-usb/dw2102.c:368:1: warning: 'dw2102_earda_i2c_transfer' uses dynamic stack allocation [enabled by default] drivers/media/usb/dvb-usb/dw2102.c:449:1: warning: 'dw2104_i2c_transfer' uses dynamic stack allocation [enabled by default] drivers/media/usb/dvb-usb/dw2102.c:512:1: warning: 'dw3101_i2c_transfer' uses dynamic stack allocation [enabled by default] drivers/media/usb/dvb-usb/dw2102.c:621:1: warning: 's6x0_i2c_transfer' 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 (64 bytes). Signed-off-by: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx> Reviewed-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> Signed-off-by: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx> [bwh: Backported to 3.2: adjust filename, context] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- drivers/media/dvb/dvb-usb/dw2102.c | 90 +++++++++++++++++++++++++++++++++----- 1 file changed, 80 insertions(+), 10 deletions(-) --- a/drivers/media/dvb/dvb-usb/dw2102.c +++ b/drivers/media/dvb/dvb-usb/dw2102.c @@ -28,6 +28,9 @@ #include "stb6100.h" #include "stb6100_proc.h" +/* Max transfer size done by I2C transfer functions */ +#define MAX_XFER_SIZE 64 + #ifndef USB_PID_DW2102 #define USB_PID_DW2102 0x2102 #endif @@ -287,7 +290,14 @@ static int dw2102_earda_i2c_transfer(str case 2: { /* read */ /* first write first register number */ - u8 ibuf[msg[1].len + 2], obuf[3]; + u8 ibuf[MAX_XFER_SIZE], obuf[3]; + + if (2 + msg[1].len > sizeof(ibuf)) { + warn("i2c rd: len=%d is too big!\n", + msg[1].len); + return -EOPNOTSUPP; + } + obuf[0] = msg[0].addr << 1; obuf[1] = msg[0].len; obuf[2] = msg[0].buf[0]; @@ -304,7 +314,14 @@ static int dw2102_earda_i2c_transfer(str switch (msg[0].addr) { case 0x68: { /* write to register */ - u8 obuf[msg[0].len + 2]; + u8 obuf[MAX_XFER_SIZE]; + + if (2 + msg[0].len > sizeof(obuf)) { + warn("i2c wr: len=%d is too big!\n", + msg[1].len); + return -EOPNOTSUPP; + } + obuf[0] = msg[0].addr << 1; obuf[1] = msg[0].len; memcpy(obuf + 2, msg[0].buf, msg[0].len); @@ -314,7 +331,14 @@ static int dw2102_earda_i2c_transfer(str } case 0x61: { /* write to tuner */ - u8 obuf[msg[0].len + 2]; + u8 obuf[MAX_XFER_SIZE]; + + if (2 + msg[0].len > sizeof(obuf)) { + warn("i2c wr: len=%d is too big!\n", + msg[1].len); + return -EOPNOTSUPP; + } + obuf[0] = msg[0].addr << 1; obuf[1] = msg[0].len; memcpy(obuf + 2, msg[0].buf, msg[0].len); @@ -381,7 +405,14 @@ static int dw2104_i2c_transfer(struct i2 default: { if (msg[j].flags == I2C_M_RD) { /* read registers */ - u8 ibuf[msg[j].len + 2]; + u8 ibuf[MAX_XFER_SIZE]; + + if (2 + msg[j].len > sizeof(ibuf)) { + warn("i2c rd: len=%d is too big!\n", + msg[j].len); + return -EOPNOTSUPP; + } + ret = dw210x_op_rw(d->udev, 0xc3, (msg[j].addr << 1) + 1, 0, ibuf, msg[j].len + 2, @@ -410,7 +441,14 @@ static int dw2104_i2c_transfer(struct i2 } while (len > 0); } else { /* write registers */ - u8 obuf[msg[j].len + 2]; + u8 obuf[MAX_XFER_SIZE]; + + if (2 + msg[j].len > sizeof(obuf)) { + warn("i2c wr: len=%d is too big!\n", + msg[j].len); + return -EOPNOTSUPP; + } + obuf[0] = msg[j].addr << 1; obuf[1] = msg[j].len; memcpy(obuf + 2, msg[j].buf, msg[j].len); @@ -443,7 +481,13 @@ static int dw3101_i2c_transfer(struct i2 case 2: { /* read */ /* first write first register number */ - u8 ibuf[msg[1].len + 2], obuf[3]; + u8 ibuf[MAX_XFER_SIZE], obuf[3]; + + if (2 + msg[1].len > sizeof(ibuf)) { + warn("i2c rd: len=%d is too big!\n", + msg[1].len); + return -EOPNOTSUPP; + } obuf[0] = msg[0].addr << 1; obuf[1] = msg[0].len; obuf[2] = msg[0].buf[0]; @@ -461,7 +505,13 @@ static int dw3101_i2c_transfer(struct i2 case 0x60: case 0x0c: { /* write to register */ - u8 obuf[msg[0].len + 2]; + u8 obuf[MAX_XFER_SIZE]; + + if (2 + msg[0].len > sizeof(obuf)) { + warn("i2c wr: len=%d is too big!\n", + msg[0].len); + return -EOPNOTSUPP; + } obuf[0] = msg[0].addr << 1; obuf[1] = msg[0].len; memcpy(obuf + 2, msg[0].buf, msg[0].len); @@ -544,7 +594,14 @@ static int s6x0_i2c_transfer(struct i2c_ default: { if (msg[j].flags == I2C_M_RD) { /* read registers */ - u8 ibuf[msg[j].len]; + u8 ibuf[MAX_XFER_SIZE]; + + if (msg[j].len > sizeof(ibuf)) { + warn("i2c rd: len=%d is too big!\n", + msg[j].len); + return -EOPNOTSUPP; + } + ret = dw210x_op_rw(d->udev, 0x91, 0, 0, ibuf, msg[j].len, DW210X_READ_MSG); @@ -571,7 +628,14 @@ static int s6x0_i2c_transfer(struct i2c_ } while (len > 0); } else if (j < (num - 1)) { /* write register addr before read */ - u8 obuf[msg[j].len + 2]; + u8 obuf[MAX_XFER_SIZE]; + + if (2 + msg[j].len > sizeof(obuf)) { + warn("i2c wr: len=%d is too big!\n", + msg[j].len); + return -EOPNOTSUPP; + } + obuf[0] = msg[j + 1].len; obuf[1] = (msg[j].addr << 1); memcpy(obuf + 2, msg[j].buf, msg[j].len); @@ -583,7 +647,13 @@ static int s6x0_i2c_transfer(struct i2c_ break; } else { /* write registers */ - u8 obuf[msg[j].len + 2]; + u8 obuf[MAX_XFER_SIZE]; + + if (2 + msg[j].len > sizeof(obuf)) { + warn("i2c wr: len=%d is too big!\n", + msg[j].len); + return -EOPNOTSUPP; + } obuf[0] = msg[j].len + 1; obuf[1] = (msg[j].addr << 1); memcpy(obuf + 2, msg[j].buf, msg[j].len);