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authorDan Carpenter <dan.carpenter@oracle.com>2012-09-11 07:11:24 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2012-10-06 09:24:39 -0300
commit48cafec9a941c2dfe94d76642662bc20bf87fe08 (patch)
tree135943901bfccdb6a8e260fed60c6583fcc8021b
parenta52eb6c02fa27efb5f8980312785fce1f77377e2 (diff)
downloadop-kernel-dev-48cafec9a941c2dfe94d76642662bc20bf87fe08.zip
op-kernel-dev-48cafec9a941c2dfe94d76642662bc20bf87fe08.tar.gz
[media] rc: divide by zero bugs in s_tx_carrier()
"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>
-rw-r--r--drivers/media/rc/ene_ir.c5
-rw-r--r--drivers/media/rc/nuvoton-cir.c3
-rw-r--r--drivers/media/rc/redrat3.c3
3 files changed, 10 insertions, 1 deletions
diff --git a/drivers/media/rc/ene_ir.c b/drivers/media/rc/ene_ir.c
index 647dd95..d05ac15 100644
--- a/drivers/media/rc/ene_ir.c
+++ b/drivers/media/rc/ene_ir.c
@@ -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)) {
diff --git a/drivers/media/rc/nuvoton-cir.c b/drivers/media/rc/nuvoton-cir.c
index 699eef3..2ea913a 100644
--- a/drivers/media/rc/nuvoton-cir.c
+++ b/drivers/media/rc/nuvoton-cir.c
@@ -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);
diff --git a/drivers/media/rc/redrat3.c b/drivers/media/rc/redrat3.c
index 49731b1..9f5a17b 100644
--- a/drivers/media/rc/redrat3.c
+++ b/drivers/media/rc/redrat3.c
@@ -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;
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