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authorMauro Carvalho Chehab <mchehab@s-opensource.com>2016-10-07 06:53:51 -0300
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2016-10-14 12:38:10 -0300
commitfa1ecd8dc454fe2d3075a964240f45ceb60cb9e0 (patch)
treebd166264a1a6460fa1c2ebd477bc99da3335d76e
parentbd1f976cc95b0689f889c8d93434ee61dd09b08b (diff)
[media] dib0700_core: don't use stack on I2C reads
Be sure that I2C reads won't use stack by passing a pointer to the state buffer, that we know it was allocated via kmalloc, instead of relying on the buffer allocated by an I2C client. Reviewed-by: Patrick Boettcher <patrick.boettcher@posteo.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
-rw-r--r--drivers/media/usb/dvb-usb/dib0700_core.c27
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/media/usb/dvb-usb/dib0700_core.c b/drivers/media/usb/dvb-usb/dib0700_core.c
index 515f89dba199..92d5408684ac 100644
--- a/drivers/media/usb/dvb-usb/dib0700_core.c
+++ b/drivers/media/usb/dvb-usb/dib0700_core.c
@@ -213,7 +213,7 @@ static int dib0700_i2c_xfer_new(struct i2c_adapter *adap, struct i2c_msg *msg,
usb_rcvctrlpipe(d->udev, 0),
REQUEST_NEW_I2C_READ,
USB_TYPE_VENDOR | USB_DIR_IN,
- value, index, msg[i].buf,
+ value, index, st->buf,
msg[i].len,
USB_CTRL_GET_TIMEOUT);
if (result < 0) {
@@ -221,6 +221,14 @@ static int dib0700_i2c_xfer_new(struct i2c_adapter *adap, struct i2c_msg *msg,
break;
}
+ if (msg[i].len > sizeof(st->buf)) {
+ deb_info("buffer too small to fit %d bytes\n",
+ msg[i].len);
+ return -EIO;
+ }
+
+ memcpy(msg[i].buf, st->buf, msg[i].len);
+
deb_data("<<< ");
debug_dump(msg[i].buf, msg[i].len, deb_data);
@@ -238,6 +246,13 @@ static int dib0700_i2c_xfer_new(struct i2c_adapter *adap, struct i2c_msg *msg,
/* I2C ctrl + FE bus; */
st->buf[3] = ((gen_mode << 6) & 0xC0) |
((bus_mode << 4) & 0x30);
+
+ if (msg[i].len > sizeof(st->buf) - 4) {
+ deb_info("i2c message to big: %d\n",
+ msg[i].len);
+ return -EIO;
+ }
+
/* The Actual i2c payload */
memcpy(&st->buf[4], msg[i].buf, msg[i].len);
@@ -283,6 +298,11 @@ static int dib0700_i2c_xfer_legacy(struct i2c_adapter *adap,
/* fill in the address */
st->buf[1] = msg[i].addr << 1;
/* fill the buffer */
+ if (msg[i].len > sizeof(st->buf) - 2) {
+ deb_info("i2c xfer to big: %d\n",
+ msg[i].len);
+ return -EIO;
+ }
memcpy(&st->buf[2], msg[i].buf, msg[i].len);
/* write/read request */
@@ -299,6 +319,11 @@ static int dib0700_i2c_xfer_legacy(struct i2c_adapter *adap,
break;
}
+ if (msg[i + 1].len > sizeof(st->buf)) {
+ deb_info("i2c xfer buffer to small for %d\n",
+ msg[i].len);
+ return -EIO;
+ }
memcpy(msg[i + 1].buf, st->buf, msg[i + 1].len);
msg[i+1].len = len;

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