This is a note to let you know that I've just added the patch titled
staging: comedi: dt282x: fix a null pointer deref on interrupt
to my staging git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-testing branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will be merged to the staging-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
>From b8336be66dec06bef518030a0df9847122053ec5 Mon Sep 17 00:00:00 2001
From: Ian Abbott <abbotti(a)mev.co.uk>
Date: Wed, 26 Jun 2019 14:18:04 +0100
Subject: staging: comedi: dt282x: fix a null pointer deref on interrupt
The interrupt handler `dt282x_interrupt()` causes a null pointer
dereference for those supported boards that have no analog output
support. For these boards, `dev->write_subdev` will be `NULL` and
therefore the `s_ao` subdevice pointer variable will be `NULL`. In that
case, the following call near the end of the interrupt handler results
in a null pointer dereference:
comedi_handle_events(dev, s_ao);
Fix it by only calling the above function if `s_ao` is valid.
(There are other uses of `s_ao` by the interrupt handler that may or may
not be reached depending on values of hardware registers. Trust that
they are reliable for now.)
Note:
commit 4f6f009b204f ("staging: comedi: dt282x: use comedi_handle_events()")
propagates an earlier error from
commit f21c74fa4cfe ("staging: comedi: dt282x: use cfc_handle_events()").
Fixes: 4f6f009b204f ("staging: comedi: dt282x: use comedi_handle_events()")
Cc: <stable(a)vger.kernel.org> # v3.19+
Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/staging/comedi/drivers/dt282x.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/comedi/drivers/dt282x.c b/drivers/staging/comedi/drivers/dt282x.c
index 3be927f1d3a9..e15e33ed94ae 100644
--- a/drivers/staging/comedi/drivers/dt282x.c
+++ b/drivers/staging/comedi/drivers/dt282x.c
@@ -557,7 +557,8 @@ static irqreturn_t dt282x_interrupt(int irq, void *d)
}
#endif
comedi_handle_events(dev, s);
- comedi_handle_events(dev, s_ao);
+ if (s_ao)
+ comedi_handle_events(dev, s_ao);
return IRQ_RETVAL(handled);
}
--
2.22.0
This is a note to let you know that I've just added the patch titled
staging: comedi: amplc_pci230: fix null pointer deref on interrupt
to my staging git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-testing branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will be merged to the staging-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
>From 7379e6baeddf580d01feca650ec1ad508b6ea8ee Mon Sep 17 00:00:00 2001
From: Ian Abbott <abbotti(a)mev.co.uk>
Date: Wed, 26 Jun 2019 14:17:39 +0100
Subject: staging: comedi: amplc_pci230: fix null pointer deref on interrupt
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(a)vger.kernel.org> # v3.19+
Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/staging/comedi/drivers/amplc_pci230.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
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;
--
2.22.0