diff options
| author | Ian Abbott <abbotti@mev.co.uk> | 2020-07-17 15:52:55 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-31 16:43:14 +0200 |
| commit | 8f6e2f1bca314c4b0fd06ad50c1919581ef659d7 (patch) | |
| tree | 73cc9bab729f47bde7a6f9f49d4569dc3c158a96 /drivers/staging | |
| parent | b3a6d51d79afb46f43bdcf49722d955ec03fb967 (diff) | |
staging: comedi: addi_apci_1032: check INSN_CONFIG_DIGITAL_TRIG shift
commit 0bd0db42a030b75c20028c7ba6e327b9cb554116 upstream.
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: 33cdce6293dcc ("staging: comedi: addi_apci_1032: conform to new INSN_CONFIG_DIGITAL_TRIG")
Cc: <stable@vger.kernel.org> #3.8+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20200717145257.112660-3-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging')
| -rw-r--r-- | drivers/staging/comedi/drivers/addi_apci_1032.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/drivers/staging/comedi/drivers/addi_apci_1032.c b/drivers/staging/comedi/drivers/addi_apci_1032.c index ccd1a91290bf..536a135cd00b 100644 --- a/drivers/staging/comedi/drivers/addi_apci_1032.c +++ b/drivers/staging/comedi/drivers/addi_apci_1032.c @@ -115,14 +115,22 @@ static int apci1032_cos_insn_config(struct comedi_device *dev, unsigned int *data) { struct apci1032_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; @@ -145,8 +153,8 @@ static int apci1032_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 != (APCI1032_CTRL_INT_ENA | @@ -163,8 +171,8 @@ static int apci1032_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; |