* [PATCH] cxl: Fix NULL pointer dereference on kernel contexts with no AFU interrupts
@ 2016-06-29 18:55 Ian Munsie
2016-06-29 22:28 ` Andrew Donnellan
2016-07-11 10:19 ` Michael Ellerman
0 siblings, 2 replies; 6+ messages in thread
From: Ian Munsie @ 2016-06-29 18:55 UTC (permalink / raw)
To: Michael Ellerman, mikey, linuxppc-dev, Frederic Barrat,
Huy Nguyen
Cc: Ian Munsie
From: Ian Munsie <imunsie@au1.ibm.com>
If a kernel context is initialised and does not have any AFU interrupts
allocated it will cause a NULL pointer dereference when the context is
detached since the irq_names list will not have been initialised.
Move the initialisation of the irq_names list into the cxl_context_init
routine so that it will be valid for the entire lifetime of the context
and will not cause a NULL pointer dereference.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
---
drivers/misc/cxl/context.c | 2 ++
drivers/misc/cxl/irq.c | 3 ---
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
index 26d206b..edbb99e 100644
--- a/drivers/misc/cxl/context.c
+++ b/drivers/misc/cxl/context.c
@@ -67,6 +67,8 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master,
ctx->pending_fault = false;
ctx->pending_afu_err = false;
+ INIT_LIST_HEAD(&ctx->irq_names);
+
/*
* When we have to destroy all contexts in cxl_context_detach_all() we
* end up with afu_release_irqs() called from inside a
diff --git a/drivers/misc/cxl/irq.c b/drivers/misc/cxl/irq.c
index 8def455..f3a7d4a 100644
--- a/drivers/misc/cxl/irq.c
+++ b/drivers/misc/cxl/irq.c
@@ -260,9 +260,6 @@ int afu_allocate_irqs(struct cxl_context *ctx, u32 count)
else
alloc_count = count + 1;
- /* Initialize the list head to hold irq names */
- INIT_LIST_HEAD(&ctx->irq_names);
-
if ((rc = cxl_ops->alloc_irq_ranges(&ctx->irqs, ctx->afu->adapter,
alloc_count)))
return rc;
--
2.8.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] cxl: Fix NULL pointer dereference on kernel contexts with no AFU interrupts
2016-06-29 18:55 [PATCH] cxl: Fix NULL pointer dereference on kernel contexts with no AFU interrupts Ian Munsie
@ 2016-06-29 22:28 ` Andrew Donnellan
2016-06-30 5:00 ` Michael Ellerman
2016-07-11 10:19 ` Michael Ellerman
1 sibling, 1 reply; 6+ messages in thread
From: Andrew Donnellan @ 2016-06-29 22:28 UTC (permalink / raw)
To: Ian Munsie, Michael Ellerman, mikey, linuxppc-dev,
Frederic Barrat, Huy Nguyen
On 30/06/16 04:55, Ian Munsie wrote:
> From: Ian Munsie <imunsie@au1.ibm.com>
>
> If a kernel context is initialised and does not have any AFU interrupts
> allocated it will cause a NULL pointer dereference when the context is
> detached since the irq_names list will not have been initialised.
>
> Move the initialisation of the irq_names list into the cxl_context_init
> routine so that it will be valid for the entire lifetime of the context
> and will not cause a NULL pointer dereference.
>
> Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
As it's nice having your machine not crash on every shutdown...
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
--
Andrew Donnellan OzLabs, ADL Canberra
andrew.donnellan@au1.ibm.com IBM Australia Limited
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] cxl: Fix NULL pointer dereference on kernel contexts with no AFU interrupts
2016-06-29 22:28 ` Andrew Donnellan
@ 2016-06-30 5:00 ` Michael Ellerman
2016-06-30 5:15 ` Andrew Donnellan
0 siblings, 1 reply; 6+ messages in thread
From: Michael Ellerman @ 2016-06-30 5:00 UTC (permalink / raw)
To: Andrew Donnellan, Ian Munsie, mikey, linuxppc-dev,
Frederic Barrat, Huy Nguyen
On Thu, 2016-06-30 at 08:28 +1000, Andrew Donnellan wrote:
> On 30/06/16 04:55, Ian Munsie wrote:
> >
> > From: Ian Munsie <imunsie@au1.ibm.com>
> >
> > If a kernel context is initialised and does not have any AFU interrupts
> > allocated it will cause a NULL pointer dereference when the context is
> > detached since the irq_names list will not have been initialised.
> >
> > Move the initialisation of the irq_names list into the cxl_context_init
> > routine so that it will be valid for the entire lifetime of the context
> > and will not cause a NULL pointer dereference.
> >
> > Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
> As it's nice having your machine not crash on every shutdown...
Fixes: ????
cheers
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] cxl: Fix NULL pointer dereference on kernel contexts with no AFU interrupts
2016-06-30 5:00 ` Michael Ellerman
@ 2016-06-30 5:15 ` Andrew Donnellan
2016-06-30 6:24 ` Ian Munsie
0 siblings, 1 reply; 6+ messages in thread
From: Andrew Donnellan @ 2016-06-30 5:15 UTC (permalink / raw)
To: Michael Ellerman, Ian Munsie, mikey, linuxppc-dev,
Frederic Barrat, Huy Nguyen
On 30/06/16 15:00, Michael Ellerman wrote:
> On Thu, 2016-06-30 at 08:28 +1000, Andrew Donnellan wrote:
>> On 30/06/16 04:55, Ian Munsie wrote:
>>>
>>> From: Ian Munsie <imunsie@au1.ibm.com>
>>>
>>> If a kernel context is initialised and does not have any AFU interrupts
>>> allocated it will cause a NULL pointer dereference when the context is
>>> detached since the irq_names list will not have been initialised.
>>>
>>> Move the initialisation of the irq_names list into the cxl_context_init
>>> routine so that it will be valid for the entire lifetime of the context
>>> and will not cause a NULL pointer dereference.
>>>
>>> Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
>
>> As it's nice having your machine not crash on every shutdown...
>
> Fixes: ????
Ian can correct me if I'm wrong, but I suspect this doesn't affect
cxlflash (the only current user of the cxl kernel API) - this issue was
hit while working on CAPI support for mlx5.
--
Andrew Donnellan OzLabs, ADL Canberra
andrew.donnellan@au1.ibm.com IBM Australia Limited
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] cxl: Fix NULL pointer dereference on kernel contexts with no AFU interrupts
2016-06-30 5:15 ` Andrew Donnellan
@ 2016-06-30 6:24 ` Ian Munsie
0 siblings, 0 replies; 6+ messages in thread
From: Ian Munsie @ 2016-06-30 6:24 UTC (permalink / raw)
To: andrew.donnellan
Cc: Michael Ellerman, mikey, linuxppc-dev, Frederic Barrat,
Huy Nguyen
Excerpts from andrew.donnellan's message of 2016-06-30 15:15:02 +1000:
> On 30/06/16 15:00, Michael Ellerman wrote:
> > On Thu, 2016-06-30 at 08:28 +1000, Andrew Donnellan wrote:
> >> On 30/06/16 04:55, Ian Munsie wrote:
> >>>
> >>> From: Ian Munsie <imunsie@au1.ibm.com>
> >>>
> >>> If a kernel context is initialised and does not have any AFU interrupts
> >>> allocated it will cause a NULL pointer dereference when the context is
> >>> detached since the irq_names list will not have been initialised.
> >>>
> >>> Move the initialisation of the irq_names list into the cxl_context_init
> >>> routine so that it will be valid for the entire lifetime of the context
> >>> and will not cause a NULL pointer dereference.
> >>>
> >>> Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
> >
> >> As it's nice having your machine not crash on every shutdown...
> >
> > Fixes: ????
>
> Ian can correct me if I'm wrong, but I suspect this doesn't affect
> cxlflash (the only current user of the cxl kernel API) - this issue was
> hit while working on CAPI support for mlx5.
Correct - no current user hits this bug, but the upcoming mlx5 support
does because of the way it uses interrupts.
-Ian
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: cxl: Fix NULL pointer dereference on kernel contexts with no AFU interrupts
2016-06-29 18:55 [PATCH] cxl: Fix NULL pointer dereference on kernel contexts with no AFU interrupts Ian Munsie
2016-06-29 22:28 ` Andrew Donnellan
@ 2016-07-11 10:19 ` Michael Ellerman
1 sibling, 0 replies; 6+ messages in thread
From: Michael Ellerman @ 2016-07-11 10:19 UTC (permalink / raw)
To: Ian Munsie, mikey, linuxppc-dev, Frederic Barrat, Huy Nguyen; +Cc: Ian Munsie
On Wed, 2016-29-06 at 18:55:17 UTC, Ian Munsie wrote:
> From: Ian Munsie <imunsie@au1.ibm.com>
>
> If a kernel context is initialised and does not have any AFU interrupts
> allocated it will cause a NULL pointer dereference when the context is
> detached since the irq_names list will not have been initialised.
>
> Move the initialisation of the irq_names list into the cxl_context_init
> routine so that it will be valid for the entire lifetime of the context
> and will not cause a NULL pointer dereference.
>
> Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/f5c9df9a442f586b1839476272
cheers
^ permalink raw reply [flat|nested] 6+ messages in thread
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2016-06-29 18:55 [PATCH] cxl: Fix NULL pointer dereference on kernel contexts with no AFU interrupts Ian Munsie
2016-06-29 22:28 ` Andrew Donnellan
2016-06-30 5:00 ` Michael Ellerman
2016-06-30 5:15 ` Andrew Donnellan
2016-06-30 6:24 ` Ian Munsie
2016-07-11 10:19 ` Michael Ellerman
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