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| author | Ian Abbott <abbotti@mev.co.uk> | 2019-06-26 14:17:39 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-14 08:01:12 +0200 |
| commit | f0f909a19b69abfe4cab7ddc5882f8c192806920 (patch) | |
| tree | 9823f968a529124a472fdc041fd1537a5045ea1f | |
| parent | e937d42fb0ce864004aa93fc6672ae8d4ac50bea (diff) | |
| download | linux-stable-f0f909a19b69abfe4cab7ddc5882f8c192806920.tar.gz linux-stable-f0f909a19b69abfe4cab7ddc5882f8c192806920.tar.bz2 linux-stable-f0f909a19b69abfe4cab7ddc5882f8c192806920.zip | |
staging: comedi: amplc_pci230: fix null pointer deref on interrupt
commit 7379e6baeddf580d01feca650ec1ad508b6ea8ee upstream.
The interrupt handler `pci230_interrupt()` causes a null pointer
dereference for a PCI260 card. There is no analog output subdevice for
a PCI260. The `dev->write_subdev` subdevice pointer and therefore the
`s_ao` subdevice pointer variable will be `NULL` for a PCI260. The
following call near the end of the interrupt handler results in the null
pointer dereference for a PCI260:
comedi_handle_events(dev, s_ao);
Fix it by only calling the above function if `s_ao` is valid.
Note that the other uses of `s_ao` in the calls
`pci230_handle_ao_nofifo(dev, s_ao);` and `pci230_handle_ao_fifo(dev,
s_ao);` will never be reached for a PCI260, so they are safe.
Fixes: 39064f23284c ("staging: comedi: amplc_pci230: use comedi_handle_events()")
Cc: <stable@vger.kernel.org> # v3.19+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/comedi/drivers/amplc_pci230.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/staging/comedi/drivers/amplc_pci230.c b/drivers/staging/comedi/drivers/amplc_pci230.c index 65f60c2b702a..f7e673121864 100644 --- a/drivers/staging/comedi/drivers/amplc_pci230.c +++ b/drivers/staging/comedi/drivers/amplc_pci230.c @@ -2330,7 +2330,8 @@ static irqreturn_t pci230_interrupt(int irq, void *d) devpriv->intr_running = false; spin_unlock_irqrestore(&devpriv->isr_spinlock, irqflags); - comedi_handle_events(dev, s_ao); + if (s_ao) + comedi_handle_events(dev, s_ao); comedi_handle_events(dev, s_ai); return IRQ_HANDLED; |