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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> | 2020-07-22 09:10:50 +0200 |
| commit | 9c6c379fc06c12a0dc4a43f46580b1dedc30168d (patch) | |
| tree | 094945e9b3dc4187255f1f702b62d4c9fd66d6ed | |
| parent | 755518f9dc358d3d85193c0e2e1948892f48bad2 (diff) | |
| download | linux-9c6c379fc06c12a0dc4a43f46580b1dedc30168d.tar.gz linux-9c6c379fc06c12a0dc4a43f46580b1dedc30168d.tar.bz2 linux-9c6c379fc06c12a0dc4a43f46580b1dedc30168d.zip | |
staging: comedi: verify array index is correct before using it
[ Upstream commit ef75e14a6c935eec82abac07ab68e388514e39bc ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.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 63991c49ff23..79a8799b1262 100644 --- a/drivers/staging/comedi/drivers/addi_apci_1500.c +++ b/drivers/staging/comedi/drivers/addi_apci_1500.c @@ -465,9 +465,9 @@ 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, @@ -480,6 +480,10 @@ 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 */ |