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[media] rc: divide by zero bugs in s_tx_carrier()

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"carrier" comes from a get_user() in ir_lirc_ioctl().  We need to test
that it's not zero before using it as a divisor.  It might have been
nice to test for this ir_lirc_ioctl() but the mceusb driver uses zero to
disable carrier modulation.
The bug in redrat3 is a little more subtle.  The ->carrier is passed to
mod_freq_to_val() which uses it as a divisor.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Dan Carpenter 2012-09-11 07:11:24 -03:00 committed by Mauro Carvalho Chehab
parent a52eb6c02f
commit 48cafec9a9
3 changed files with 10 additions and 1 deletions
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5
drivers/media/rc/ene_ir.c
View File

@ -881,10 +881,13 @@ static int ene_set_tx_mask(struct rc_dev *rdev, u32 tx_mask)
static int ene_set_tx_carrier(struct rc_dev *rdev, u32 carrier)
{
struct ene_device *dev = rdev->priv;
u32 period = 2000000 / carrier;
u32 period;
dbg("TX: attempt to set tx carrier to %d kHz", carrier);
if (carrier == 0)
return -EINVAL;
period = 2000000 / carrier;
if (period && (period > ENE_CIRMOD_PRD_MAX ||
period < ENE_CIRMOD_PRD_MIN)) {

3
drivers/media/rc/nuvoton-cir.c
View File

@ -517,6 +517,9 @@ static int nvt_set_tx_carrier(struct rc_dev *dev, u32 carrier)
struct nvt_dev *nvt = dev->priv;
u16 val;
if (carrier == 0)
return -EINVAL;
nvt_cir_reg_write(nvt, 1, CIR_CP);
val = 3000000 / (carrier) - 1;
nvt_cir_reg_write(nvt, val & 0xff, CIR_CC);

3
drivers/media/rc/redrat3.c
View File

@ -890,6 +890,9 @@ static int redrat3_set_tx_carrier(struct rc_dev *rcdev, u32 carrier)
struct device *dev = rr3->dev;
rr3_dbg(dev, "Setting modulation frequency to %u", carrier);
if (carrier == 0)
return -EINVAL;
rr3->carrier = carrier;
return carrier;