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| author |   Dan Carpenter <dan.carpenter@oracle.com> | 2020-07-09 13:29:36 +0300 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-10 14:03:00 +0200 |
| commit | ef75e14a6c935eec82abac07ab68e388514e39bc (patch) | |
| tree | 8f8707f25c62ad2a263acac276267a048d4e2e71 | |
| parent | Merge tag 'iio-fixes-for-5.8a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-linus (diff) | |
| download | linux-dev-ef75e14a6c935eec82abac07ab68e388514e39bc.tar.xz linux-dev-ef75e14a6c935eec82abac07ab68e388514e39bc.zip | |
staging: comedi: verify array index is correct before using it
This code reads from the array before verifying that "trig" is a valid
index. If the index is wildly out of bounds then reading from an
invalid address could lead to an Oops.
Fixes: a8c66b684efa ("staging: comedi: addi_apci_1500: rewrite the subdevice support functions")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20200709102936.GA20875@mwanda
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/comedi/drivers/addi_apci_1500.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/staging/comedi/drivers/addi_apci_1500.c b/drivers/staging/comedi/drivers/addi_apci_1500.c index 45ad4ba92f94..689acd69a1b9 100644 --- a/drivers/staging/comedi/drivers/addi_apci_1500.c +++ b/drivers/staging/comedi/drivers/addi_apci_1500.c @@ -456,9 +456,9 @@ static int apci1500_di_cfg_trig(struct comedi_device *dev, unsigned int lo_mask = data[5] << shift; unsigned int chan_mask = hi_mask | lo_mask; unsigned int old_mask = (1 << shift) - 1; - unsigned int pm = devpriv->pm[trig] & old_mask; - unsigned int pt = devpriv->pt[trig] & old_mask; - unsigned int pp = devpriv->pp[trig] & old_mask; + unsigned int pm; + unsigned int pt; + unsigned int pp; if (trig > 1) { dev_dbg(dev->class_dev, @@ -471,6 +471,10 @@ static int apci1500_di_cfg_trig(struct comedi_device *dev, return -EINVAL; } + pm = devpriv->pm[trig] & old_mask; + pt = devpriv->pt[trig] & old_mask; + pp = devpriv->pp[trig] & old_mask; + switch (data[2]) { case COMEDI_DIGITAL_TRIG_DISABLE: /* clear trigger configuration */ |