From: Ian Abbott <abbotti@mev.co.uk> To: devel@driverdev.osuosl.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Ian Abbott <abbotti@mev.co.uk>, H Hartley Sweeten <hsweeten@visionengravers.com>, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 4/4] staging: comedi: addi_apci_1500: check INSN_CONFIG_DIGITAL_TRIG shift Date: Fri, 17 Jul 2020 15:52:57 +0100 [thread overview] Message-ID: <20200717145257.112660-5-abbotti@mev.co.uk> (raw) In-Reply-To: <20200717145257.112660-1-abbotti@mev.co.uk> 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, adjusting the checks for invalid channels so that enabled channel bits that would have been lost by shifting are also checked for validity. Only channels 0 to 15 are valid. Fixes: a8c66b684efaf ("staging: comedi: addi_apci_1500: rewrite the subdevice support functions") Cc: <stable@vger.kernel.org> #4.0+: ef75e14a6c93: staging: comedi: verify array index is correct before using it Cc: <stable@vger.kernel.org> #4.0+ Signed-off-by: Ian Abbott <abbotti@mev.co.uk> --- .../staging/comedi/drivers/addi_apci_1500.c | 24 +++++++++++++++---- 1 file changed, 19 insertions(+), 5 deletions(-) diff --git a/drivers/staging/comedi/drivers/addi_apci_1500.c b/drivers/staging/comedi/drivers/addi_apci_1500.c index 689acd69a1b9..816dd25b9d0e 100644 --- a/drivers/staging/comedi/drivers/addi_apci_1500.c +++ b/drivers/staging/comedi/drivers/addi_apci_1500.c @@ -452,13 +452,14 @@ static int apci1500_di_cfg_trig(struct comedi_device *dev, struct apci1500_private *devpriv = dev->private; unsigned int trig = data[1]; unsigned int shift = data[3]; - unsigned int hi_mask = data[4] << shift; - unsigned int lo_mask = data[5] << shift; - unsigned int chan_mask = hi_mask | lo_mask; - unsigned int old_mask = (1 << shift) - 1; + unsigned int hi_mask; + unsigned int lo_mask; + unsigned int chan_mask; + unsigned int old_mask; unsigned int pm; unsigned int pt; unsigned int pp; + unsigned int invalid_chan; if (trig > 1) { dev_dbg(dev->class_dev, @@ -466,7 +467,20 @@ static int apci1500_di_cfg_trig(struct comedi_device *dev, return -EINVAL; } - if (chan_mask > 0xffff) { + if (shift <= 16) { + hi_mask = data[4] << shift; + lo_mask = data[5] << shift; + old_mask = (1U << shift) - 1; + invalid_chan = (data[4] | data[5]) >> (16 - shift); + } else { + hi_mask = 0; + lo_mask = 0; + old_mask = 0xffff; + invalid_chan = data[4] | data[5]; + } + chan_mask = hi_mask | lo_mask; + + if (invalid_chan) { dev_dbg(dev->class_dev, "invalid digital trigger channel\n"); return -EINVAL; } -- 2.27.0
WARNING: multiple messages have this Message-ID (diff)
From: Ian Abbott <abbotti@mev.co.uk> To: devel@driverdev.osuosl.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Ian Abbott <abbotti@mev.co.uk>, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 4/4] staging: comedi: addi_apci_1500: check INSN_CONFIG_DIGITAL_TRIG shift Date: Fri, 17 Jul 2020 15:52:57 +0100 [thread overview] Message-ID: <20200717145257.112660-5-abbotti@mev.co.uk> (raw) In-Reply-To: <20200717145257.112660-1-abbotti@mev.co.uk> 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, adjusting the checks for invalid channels so that enabled channel bits that would have been lost by shifting are also checked for validity. Only channels 0 to 15 are valid. Fixes: a8c66b684efaf ("staging: comedi: addi_apci_1500: rewrite the subdevice support functions") Cc: <stable@vger.kernel.org> #4.0+: ef75e14a6c93: staging: comedi: verify array index is correct before using it Cc: <stable@vger.kernel.org> #4.0+ Signed-off-by: Ian Abbott <abbotti@mev.co.uk> --- .../staging/comedi/drivers/addi_apci_1500.c | 24 +++++++++++++++---- 1 file changed, 19 insertions(+), 5 deletions(-) diff --git a/drivers/staging/comedi/drivers/addi_apci_1500.c b/drivers/staging/comedi/drivers/addi_apci_1500.c index 689acd69a1b9..816dd25b9d0e 100644 --- a/drivers/staging/comedi/drivers/addi_apci_1500.c +++ b/drivers/staging/comedi/drivers/addi_apci_1500.c @@ -452,13 +452,14 @@ static int apci1500_di_cfg_trig(struct comedi_device *dev, struct apci1500_private *devpriv = dev->private; unsigned int trig = data[1]; unsigned int shift = data[3]; - unsigned int hi_mask = data[4] << shift; - unsigned int lo_mask = data[5] << shift; - unsigned int chan_mask = hi_mask | lo_mask; - unsigned int old_mask = (1 << shift) - 1; + unsigned int hi_mask; + unsigned int lo_mask; + unsigned int chan_mask; + unsigned int old_mask; unsigned int pm; unsigned int pt; unsigned int pp; + unsigned int invalid_chan; if (trig > 1) { dev_dbg(dev->class_dev, @@ -466,7 +467,20 @@ static int apci1500_di_cfg_trig(struct comedi_device *dev, return -EINVAL; } - if (chan_mask > 0xffff) { + if (shift <= 16) { + hi_mask = data[4] << shift; + lo_mask = data[5] << shift; + old_mask = (1U << shift) - 1; + invalid_chan = (data[4] | data[5]) >> (16 - shift); + } else { + hi_mask = 0; + lo_mask = 0; + old_mask = 0xffff; + invalid_chan = data[4] | data[5]; + } + chan_mask = hi_mask | lo_mask; + + if (invalid_chan) { dev_dbg(dev->class_dev, "invalid digital trigger channel\n"); return -EINVAL; } -- 2.27.0 _______________________________________________ devel mailing list devel@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
next prev parent reply other threads:[~2020-07-17 14:53 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-07-17 14:52 [PATCH 0/4] staging: comedi: INSN_CONFIG_DIGITAL_TRIG fixes Ian Abbott 2020-07-17 14:52 ` Ian Abbott 2020-07-17 14:52 ` [PATCH 1/4] staging: comedi: ni_6527: fix INSN_CONFIG_DIGITAL_TRIG support Ian Abbott 2020-07-17 14:52 ` Ian Abbott 2020-07-17 14:52 ` [PATCH 2/4] staging: comedi: addi_apci_1032: check INSN_CONFIG_DIGITAL_TRIG shift Ian Abbott 2020-07-17 14:52 ` Ian Abbott 2020-07-17 14:52 ` [PATCH 3/4] staging: comedi: addi_apci_1564: " Ian Abbott 2020-07-17 14:52 ` Ian Abbott 2020-07-17 14:52 ` Ian Abbott [this message] 2020-07-17 14:52 ` [PATCH 4/4] staging: comedi: addi_apci_1500: " Ian Abbott 2020-07-20 8:19 ` [PATCH 0/4] staging: comedi: INSN_CONFIG_DIGITAL_TRIG fixes Greg Kroah-Hartman 2020-07-20 8:19 ` Greg Kroah-Hartman
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