[PATCH 18/26] gp8psk: don't go past the buffer size

From: Mauro Carvalho Chehab
Date: Fri Oct 07 2016 - 13:26:06 EST


Add checks to avoid going out of the buffer.

Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
---
drivers/media/usb/dvb-usb/gp8psk.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/drivers/media/usb/dvb-usb/gp8psk.c b/drivers/media/usb/dvb-usb/gp8psk.c
index fa215ad37f7b..a745cf636846 100644
--- a/drivers/media/usb/dvb-usb/gp8psk.c
+++ b/drivers/media/usb/dvb-usb/gp8psk.c
@@ -60,6 +60,9 @@ int gp8psk_usb_in_op(struct dvb_usb_device *d, u8 req, u16 value, u16 index, u8
struct gp8psk_state *st = d->priv;
int ret = 0,try = 0;

+ if (blen > sizeof(st->data))
+ return -EIO;
+
if ((ret = mutex_lock_interruptible(&d->usb_mutex)))
return ret;

@@ -98,6 +101,9 @@ int gp8psk_usb_out_op(struct dvb_usb_device *d, u8 req, u16 value,
deb_xfer("out: req. %x, val: %x, ind: %x, buffer: ",req,value,index);
debug_dump(b,blen,deb_xfer);

+ if (blen > sizeof(st->data))
+ return -EIO;
+
if ((ret = mutex_lock_interruptible(&d->usb_mutex)))
return ret;

@@ -151,6 +157,11 @@ static int gp8psk_load_bcm4500fw(struct dvb_usb_device *d)
err("failed to load bcm4500 firmware.");
goto out_free;
}
+ if (buflen > 64) {
+ err("firmare chunk size bigger than 64 bytes.");
+ goto out_free;
+ }
+
memcpy(buf, ptr, buflen);
if (dvb_usb_generic_write(d, buf, buflen)) {
err("failed to load bcm4500 firmware.");
--
2.7.4