diff options
| author | Ian Abbott <abbotti@mev.co.uk> | 2020-07-17 16:52:56 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-20 10:19:03 +0200 |
| commit | 926234f1b8434c4409aa4c53637aa3362ca07cea (patch) | |
| tree | dc236450840de8b3b5af4f66237e5488528e5968 /drivers | |
| parent | staging: comedi: addi_apci_1500: check INSN_CONFIG_DIGITAL_TRIG shift (diff) | |
| download | linux-926234f1b8434c4409aa4c53637aa3362ca07cea.tar.xz linux-926234f1b8434c4409aa4c53637aa3362ca07cea.zip | |
staging: comedi: addi_apci_1564: check INSN_CONFIG_DIGITAL_TRIG shift
The `INSN_CONFIG` comedi instruction with sub-instruction code
`INSN_CONFIG_DIGITAL_TRIG` includes a base channel in `data[3]`. This is
used as a right shift amount for other bitmask values without being
checked. Shift amounts greater than or equal to 32 will result in
undefined behavior. Add code to deal with this.
Fixes: 1e15687ea472 ("staging: comedi: addi_apci_1564: add Change-of-State interrupt subdevice and required functions")
Cc: <stable@vger.kernel.org> #3.17+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20200717145257.112660-4-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/staging/comedi/drivers/addi_apci_1564.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/drivers/staging/comedi/drivers/addi_apci_1564.c b/drivers/staging/comedi/drivers/addi_apci_1564.c index 10501fe6bb25..1268ba34be5f 100644 --- a/drivers/staging/comedi/drivers/addi_apci_1564.c +++ b/drivers/staging/comedi/drivers/addi_apci_1564.c @@ -331,14 +331,22 @@ static int apci1564_cos_insn_config(struct comedi_device *dev, unsigned int *data) { struct apci1564_private *devpriv = dev->private; - unsigned int shift, oldmask; + unsigned int shift, oldmask, himask, lomask; switch (data[0]) { case INSN_CONFIG_DIGITAL_TRIG: if (data[1] != 0) return -EINVAL; shift = data[3]; - oldmask = (1U << shift) - 1; + if (shift < 32) { + oldmask = (1U << shift) - 1; + himask = data[4] << shift; + lomask = data[5] << shift; + } else { + oldmask = 0xffffffffu; + himask = 0; + lomask = 0; + } switch (data[2]) { case COMEDI_DIGITAL_TRIG_DISABLE: devpriv->ctrl = 0; @@ -362,8 +370,8 @@ static int apci1564_cos_insn_config(struct comedi_device *dev, devpriv->mode2 &= oldmask; } /* configure specified channels */ - devpriv->mode1 |= data[4] << shift; - devpriv->mode2 |= data[5] << shift; + devpriv->mode1 |= himask; + devpriv->mode2 |= lomask; break; case COMEDI_DIGITAL_TRIG_ENABLE_LEVELS: if (devpriv->ctrl != (APCI1564_DI_IRQ_ENA | @@ -380,8 +388,8 @@ static int apci1564_cos_insn_config(struct comedi_device *dev, devpriv->mode2 &= oldmask; } /* configure specified channels */ - devpriv->mode1 |= data[4] << shift; - devpriv->mode2 |= data[5] << shift; + devpriv->mode1 |= himask; + devpriv->mode2 |= lomask; break; default: return -EINVAL; |