* [PATCH] ACPI / memhotplug: Fix a stale pointer in error path
@ 2013-07-10 16:47 Toshi Kani
2013-07-12 0:24 ` Yasuaki Ishimatsu
0 siblings, 1 reply; 12+ messages in thread
From: Toshi Kani @ 2013-07-10 16:47 UTC (permalink / raw)
To: rjw; +Cc: linux-acpi, linux-kernel, Toshi Kani
device->driver_data needs to be cleared when releasing its data,
mem_device, in an error path of acpi_memory_device_add().
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
---
drivers/acpi/acpi_memhotplug.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index c711d11..999adb5 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -323,6 +323,7 @@ static int acpi_memory_device_add(struct acpi_device *device,
/* Get the range from the _CRS */
result = acpi_memory_get_device_resources(mem_device);
if (result) {
+ device->driver_data = NULL;
kfree(mem_device);
return result;
}
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH] ACPI / memhotplug: Fix a stale pointer in error path
2013-07-10 16:47 [PATCH] ACPI / memhotplug: Fix a stale pointer in error path Toshi Kani
@ 2013-07-12 0:24 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 12+ messages in thread
From: Yasuaki Ishimatsu @ 2013-07-12 0:24 UTC (permalink / raw)
To: Toshi Kani; +Cc: rjw, linux-acpi, linux-kernel
(2013/07/11 1:47), Toshi Kani wrote:
> device->driver_data needs to be cleared when releasing its data,
> mem_device, in an error path of acpi_memory_device_add().
>
> Signed-off-by: Toshi Kani <toshi.kani@hp.com>
> ---
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Thanks,
Yasuaki Ishimatsu
> drivers/acpi/acpi_memhotplug.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> index c711d11..999adb5 100644
> --- a/drivers/acpi/acpi_memhotplug.c
> +++ b/drivers/acpi/acpi_memhotplug.c
> @@ -323,6 +323,7 @@ static int acpi_memory_device_add(struct acpi_device *device,
> /* Get the range from the _CRS */
> result = acpi_memory_get_device_resources(mem_device);
> if (result) {
> + device->driver_data = NULL;
> kfree(mem_device);
> return result;
> }
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] ACPI / memhotplug: Fix a stale pointer in error path
@ 2013-07-12 0:24 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 12+ messages in thread
From: Yasuaki Ishimatsu @ 2013-07-12 0:24 UTC (permalink / raw)
To: Toshi Kani; +Cc: rjw, linux-acpi, linux-kernel
(2013/07/11 1:47), Toshi Kani wrote:
> device->driver_data needs to be cleared when releasing its data,
> mem_device, in an error path of acpi_memory_device_add().
>
> Signed-off-by: Toshi Kani <toshi.kani@hp.com>
> ---
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Thanks,
Yasuaki Ishimatsu
> drivers/acpi/acpi_memhotplug.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> index c711d11..999adb5 100644
> --- a/drivers/acpi/acpi_memhotplug.c
> +++ b/drivers/acpi/acpi_memhotplug.c
> @@ -323,6 +323,7 @@ static int acpi_memory_device_add(struct acpi_device *device,
> /* Get the range from the _CRS */
> result = acpi_memory_get_device_resources(mem_device);
> if (result) {
> + device->driver_data = NULL;
> kfree(mem_device);
> return result;
> }
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] ACPI / memhotplug: Fix a stale pointer in error path
2013-07-12 0:24 ` Yasuaki Ishimatsu
(?)
@ 2013-07-12 14:51 ` Toshi Kani
2013-07-12 20:42 ` Rafael J. Wysocki
-1 siblings, 1 reply; 12+ messages in thread
From: Toshi Kani @ 2013-07-12 14:51 UTC (permalink / raw)
To: Yasuaki Ishimatsu; +Cc: rjw, linux-acpi, linux-kernel
On Fri, 2013-07-12 at 09:24 +0900, Yasuaki Ishimatsu wrote:
> (2013/07/11 1:47), Toshi Kani wrote:
> > device->driver_data needs to be cleared when releasing its data,
> > mem_device, in an error path of acpi_memory_device_add().
> >
> > Signed-off-by: Toshi Kani <toshi.kani@hp.com>
> > ---
>
> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Thanks Yasuaki!
-Toshi
>
> Thanks,
> Yasuaki Ishimatsu
>
> > drivers/acpi/acpi_memhotplug.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> > index c711d11..999adb5 100644
> > --- a/drivers/acpi/acpi_memhotplug.c
> > +++ b/drivers/acpi/acpi_memhotplug.c
> > @@ -323,6 +323,7 @@ static int acpi_memory_device_add(struct acpi_device *device,
> > /* Get the range from the _CRS */
> > result = acpi_memory_get_device_resources(mem_device);
> > if (result) {
> > + device->driver_data = NULL;
> > kfree(mem_device);
> > return result;
> > }
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
>
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] ACPI / memhotplug: Fix a stale pointer in error path
2013-07-12 14:51 ` Toshi Kani
@ 2013-07-12 20:42 ` Rafael J. Wysocki
2013-07-12 21:01 ` Toshi Kani
0 siblings, 1 reply; 12+ messages in thread
From: Rafael J. Wysocki @ 2013-07-12 20:42 UTC (permalink / raw)
To: Toshi Kani; +Cc: Yasuaki Ishimatsu, linux-acpi, linux-kernel
On Friday, July 12, 2013 08:51:29 AM Toshi Kani wrote:
> On Fri, 2013-07-12 at 09:24 +0900, Yasuaki Ishimatsu wrote:
> > (2013/07/11 1:47), Toshi Kani wrote:
> > > device->driver_data needs to be cleared when releasing its data,
> > > mem_device, in an error path of acpi_memory_device_add().
> > >
> > > Signed-off-by: Toshi Kani <toshi.kani@hp.com>
> > > ---
> >
> > Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>
> Thanks Yasuaki!
Queued up as a fix for 3.11.
Do we need that in -stable as well?
Rafael
> >
> > > drivers/acpi/acpi_memhotplug.c | 1 +
> > > 1 file changed, 1 insertion(+)
> > >
> > > diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> > > index c711d11..999adb5 100644
> > > --- a/drivers/acpi/acpi_memhotplug.c
> > > +++ b/drivers/acpi/acpi_memhotplug.c
> > > @@ -323,6 +323,7 @@ static int acpi_memory_device_add(struct acpi_device *device,
> > > /* Get the range from the _CRS */
> > > result = acpi_memory_get_device_resources(mem_device);
> > > if (result) {
> > > + device->driver_data = NULL;
> > > kfree(mem_device);
> > > return result;
> > > }
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> > > the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > >
> >
> >
>
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] ACPI / memhotplug: Fix a stale pointer in error path
2013-07-12 20:42 ` Rafael J. Wysocki
@ 2013-07-12 21:01 ` Toshi Kani
2013-07-12 21:13 ` Rafael J. Wysocki
0 siblings, 1 reply; 12+ messages in thread
From: Toshi Kani @ 2013-07-12 21:01 UTC (permalink / raw)
To: Rafael J. Wysocki; +Cc: Yasuaki Ishimatsu, linux-acpi, linux-kernel
On Fri, 2013-07-12 at 22:42 +0200, Rafael J. Wysocki wrote:
> On Friday, July 12, 2013 08:51:29 AM Toshi Kani wrote:
> > On Fri, 2013-07-12 at 09:24 +0900, Yasuaki Ishimatsu wrote:
> > > (2013/07/11 1:47), Toshi Kani wrote:
> > > > device->driver_data needs to be cleared when releasing its data,
> > > > mem_device, in an error path of acpi_memory_device_add().
> > > >
> > > > Signed-off-by: Toshi Kani <toshi.kani@hp.com>
> > > > ---
> > >
> > > Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
> >
> > Thanks Yasuaki!
>
> Queued up as a fix for 3.11.
Thanks!
> Do we need that in -stable as well?
Good point. Yes, we need that in -stable as well.
-Toshi
> Rafael
>
>
> > >
> > > > drivers/acpi/acpi_memhotplug.c | 1 +
> > > > 1 file changed, 1 insertion(+)
> > > >
> > > > diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> > > > index c711d11..999adb5 100644
> > > > --- a/drivers/acpi/acpi_memhotplug.c
> > > > +++ b/drivers/acpi/acpi_memhotplug.c
> > > > @@ -323,6 +323,7 @@ static int acpi_memory_device_add(struct acpi_device *device,
> > > > /* Get the range from the _CRS */
> > > > result = acpi_memory_get_device_resources(mem_device);
> > > > if (result) {
> > > > + device->driver_data = NULL;
> > > > kfree(mem_device);
> > > > return result;
> > > > }
> > > > --
> > > > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> > > > the body of a message to majordomo@vger.kernel.org
> > > > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > > >
> > >
> > >
> >
> >
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] ACPI / memhotplug: Fix a stale pointer in error path
2013-07-12 21:13 ` Rafael J. Wysocki
@ 2013-07-12 21:12 ` Toshi Kani
2013-07-12 21:40 ` Rafael J. Wysocki
0 siblings, 1 reply; 12+ messages in thread
From: Toshi Kani @ 2013-07-12 21:12 UTC (permalink / raw)
To: Rafael J. Wysocki; +Cc: Yasuaki Ishimatsu, linux-acpi, linux-kernel
On Fri, 2013-07-12 at 23:13 +0200, Rafael J. Wysocki wrote:
> On Friday, July 12, 2013 03:01:15 PM Toshi Kani wrote:
> > On Fri, 2013-07-12 at 22:42 +0200, Rafael J. Wysocki wrote:
> > > On Friday, July 12, 2013 08:51:29 AM Toshi Kani wrote:
> > > > On Fri, 2013-07-12 at 09:24 +0900, Yasuaki Ishimatsu wrote:
> > > > > (2013/07/11 1:47), Toshi Kani wrote:
> > > > > > device->driver_data needs to be cleared when releasing its data,
> > > > > > mem_device, in an error path of acpi_memory_device_add().
> > > > > >
> > > > > > Signed-off-by: Toshi Kani <toshi.kani@hp.com>
> > > > > > ---
> > > > >
> > > > > Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
> > > >
> > > > Thanks Yasuaki!
> > >
> > > Queued up as a fix for 3.11.
> >
> > Thanks!
> >
> > > Do we need that in -stable as well?
> >
> > Good point. Yes, we need that in -stable as well.
>
> What's the oldest mainline major release that fix is applicable to?
The fix is applicable all ways up to 2.6.32.
Thanks,
-Toshi
>
> Rafael
>
>
> > > > > > drivers/acpi/acpi_memhotplug.c | 1 +
> > > > > > 1 file changed, 1 insertion(+)
> > > > > >
> > > > > > diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> > > > > > index c711d11..999adb5 100644
> > > > > > --- a/drivers/acpi/acpi_memhotplug.c
> > > > > > +++ b/drivers/acpi/acpi_memhotplug.c
> > > > > > @@ -323,6 +323,7 @@ static int acpi_memory_device_add(struct acpi_device *device,
> > > > > > /* Get the range from the _CRS */
> > > > > > result = acpi_memory_get_device_resources(mem_device);
> > > > > > if (result) {
> > > > > > + device->driver_data = NULL;
> > > > > > kfree(mem_device);
> > > > > > return result;
> > > > > > }
> > > > > > --
> > > > > > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> > > > > > the body of a message to majordomo@vger.kernel.org
> > > > > > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> >
> >
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] ACPI / memhotplug: Fix a stale pointer in error path
2013-07-12 21:01 ` Toshi Kani
@ 2013-07-12 21:13 ` Rafael J. Wysocki
2013-07-12 21:12 ` Toshi Kani
0 siblings, 1 reply; 12+ messages in thread
From: Rafael J. Wysocki @ 2013-07-12 21:13 UTC (permalink / raw)
To: Toshi Kani; +Cc: Yasuaki Ishimatsu, linux-acpi, linux-kernel
On Friday, July 12, 2013 03:01:15 PM Toshi Kani wrote:
> On Fri, 2013-07-12 at 22:42 +0200, Rafael J. Wysocki wrote:
> > On Friday, July 12, 2013 08:51:29 AM Toshi Kani wrote:
> > > On Fri, 2013-07-12 at 09:24 +0900, Yasuaki Ishimatsu wrote:
> > > > (2013/07/11 1:47), Toshi Kani wrote:
> > > > > device->driver_data needs to be cleared when releasing its data,
> > > > > mem_device, in an error path of acpi_memory_device_add().
> > > > >
> > > > > Signed-off-by: Toshi Kani <toshi.kani@hp.com>
> > > > > ---
> > > >
> > > > Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
> > >
> > > Thanks Yasuaki!
> >
> > Queued up as a fix for 3.11.
>
> Thanks!
>
> > Do we need that in -stable as well?
>
> Good point. Yes, we need that in -stable as well.
What's the oldest mainline major release that fix is applicable to?
Rafael
> > > > > drivers/acpi/acpi_memhotplug.c | 1 +
> > > > > 1 file changed, 1 insertion(+)
> > > > >
> > > > > diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> > > > > index c711d11..999adb5 100644
> > > > > --- a/drivers/acpi/acpi_memhotplug.c
> > > > > +++ b/drivers/acpi/acpi_memhotplug.c
> > > > > @@ -323,6 +323,7 @@ static int acpi_memory_device_add(struct acpi_device *device,
> > > > > /* Get the range from the _CRS */
> > > > > result = acpi_memory_get_device_resources(mem_device);
> > > > > if (result) {
> > > > > + device->driver_data = NULL;
> > > > > kfree(mem_device);
> > > > > return result;
> > > > > }
> > > > > --
> > > > > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> > > > > the body of a message to majordomo@vger.kernel.org
> > > > > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > > > >
> > > >
> > > >
> > >
> > >
>
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] ACPI / memhotplug: Fix a stale pointer in error path
2013-07-12 21:12 ` Toshi Kani
@ 2013-07-12 21:40 ` Rafael J. Wysocki
2013-07-12 22:28 ` Toshi Kani
0 siblings, 1 reply; 12+ messages in thread
From: Rafael J. Wysocki @ 2013-07-12 21:40 UTC (permalink / raw)
To: Toshi Kani; +Cc: Yasuaki Ishimatsu, linux-acpi, linux-kernel
On Friday, July 12, 2013 03:12:24 PM Toshi Kani wrote:
> On Fri, 2013-07-12 at 23:13 +0200, Rafael J. Wysocki wrote:
> > On Friday, July 12, 2013 03:01:15 PM Toshi Kani wrote:
> > > On Fri, 2013-07-12 at 22:42 +0200, Rafael J. Wysocki wrote:
> > > > On Friday, July 12, 2013 08:51:29 AM Toshi Kani wrote:
> > > > > On Fri, 2013-07-12 at 09:24 +0900, Yasuaki Ishimatsu wrote:
> > > > > > (2013/07/11 1:47), Toshi Kani wrote:
> > > > > > > device->driver_data needs to be cleared when releasing its data,
> > > > > > > mem_device, in an error path of acpi_memory_device_add().
> > > > > > >
> > > > > > > Signed-off-by: Toshi Kani <toshi.kani@hp.com>
> > > > > > > ---
> > > > > >
> > > > > > Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
> > > > >
> > > > > Thanks Yasuaki!
> > > >
> > > > Queued up as a fix for 3.11.
> > >
> > > Thanks!
> > >
> > > > Do we need that in -stable as well?
> > >
> > > Good point. Yes, we need that in -stable as well.
> >
> > What's the oldest mainline major release that fix is applicable to?
>
> The fix is applicable all ways up to 2.6.32.
For -stable I'll need to say some more about what practical consequences of
the bug are. Is it difficult to trigger?
Rafael
> > > > > > > drivers/acpi/acpi_memhotplug.c | 1 +
> > > > > > > 1 file changed, 1 insertion(+)
> > > > > > >
> > > > > > > diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> > > > > > > index c711d11..999adb5 100644
> > > > > > > --- a/drivers/acpi/acpi_memhotplug.c
> > > > > > > +++ b/drivers/acpi/acpi_memhotplug.c
> > > > > > > @@ -323,6 +323,7 @@ static int acpi_memory_device_add(struct acpi_device *device,
> > > > > > > /* Get the range from the _CRS */
> > > > > > > result = acpi_memory_get_device_resources(mem_device);
> > > > > > > if (result) {
> > > > > > > + device->driver_data = NULL;
> > > > > > > kfree(mem_device);
> > > > > > > return result;
> > > > > > > }
> > > > > > > --
> > > > > > > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> > > > > > > the body of a message to majordomo@vger.kernel.org
> > > > > > > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > >
> > >
>
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] ACPI / memhotplug: Fix a stale pointer in error path
2013-07-12 21:40 ` Rafael J. Wysocki
@ 2013-07-12 22:28 ` Toshi Kani
2013-07-12 23:53 ` Rafael J. Wysocki
0 siblings, 1 reply; 12+ messages in thread
From: Toshi Kani @ 2013-07-12 22:28 UTC (permalink / raw)
To: Rafael J. Wysocki; +Cc: Yasuaki Ishimatsu, linux-acpi, linux-kernel
On Fri, 2013-07-12 at 23:40 +0200, Rafael J. Wysocki wrote:
> On Friday, July 12, 2013 03:12:24 PM Toshi Kani wrote:
> > On Fri, 2013-07-12 at 23:13 +0200, Rafael J. Wysocki wrote:
> > > On Friday, July 12, 2013 03:01:15 PM Toshi Kani wrote:
> > > > On Fri, 2013-07-12 at 22:42 +0200, Rafael J. Wysocki wrote:
> > > > > On Friday, July 12, 2013 08:51:29 AM Toshi Kani wrote:
> > > > > > On Fri, 2013-07-12 at 09:24 +0900, Yasuaki Ishimatsu wrote:
> > > > > > > (2013/07/11 1:47), Toshi Kani wrote:
> > > > > > > > device->driver_data needs to be cleared when releasing its data,
> > > > > > > > mem_device, in an error path of acpi_memory_device_add().
> > > > > > > >
> > > > > > > > Signed-off-by: Toshi Kani <toshi.kani@hp.com>
> > > > > > > > ---
> > > > > > >
> > > > > > > Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
> > > > > >
> > > > > > Thanks Yasuaki!
> > > > >
> > > > > Queued up as a fix for 3.11.
> > > >
> > > > Thanks!
> > > >
> > > > > Do we need that in -stable as well?
> > > >
> > > > Good point. Yes, we need that in -stable as well.
> > >
> > > What's the oldest mainline major release that fix is applicable to?
> >
> > The fix is applicable all ways up to 2.6.32.
>
> For -stable I'll need to say some more about what practical consequences of
> the bug are. Is it difficult to trigger?
The function evaluates _CRS of memory device objects, and fails when it
gets an unexpected resource or cannot allocate a memory. A kernel crash
or data corruption may occur when the kernel accessed a stale pointer.
That said, I am not sure how critical this issue is for old kernels
since I do not think there are many platforms that support memory
hotplug today. After reading the recent -stable discussion on LKML, now
I am not sure if this fix should be applied for -stable. I instrumented
the kernel to generate an error for testing this change.
Thanks,
-Toshi
>
> Rafael
>
>
> > > > > > > > drivers/acpi/acpi_memhotplug.c | 1 +
> > > > > > > > 1 file changed, 1 insertion(+)
> > > > > > > >
> > > > > > > > diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> > > > > > > > index c711d11..999adb5 100644
> > > > > > > > --- a/drivers/acpi/acpi_memhotplug.c
> > > > > > > > +++ b/drivers/acpi/acpi_memhotplug.c
> > > > > > > > @@ -323,6 +323,7 @@ static int acpi_memory_device_add(struct acpi_device *device,
> > > > > > > > /* Get the range from the _CRS */
> > > > > > > > result = acpi_memory_get_device_resources(mem_device);
> > > > > > > > if (result) {
> > > > > > > > + device->driver_data = NULL;
> > > > > > > > kfree(mem_device);
> > > > > > > > return result;
> > > > > > > > }
> > > > > > > > --
> > > > > > > > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> > > > > > > > the body of a message to majordomo@vger.kernel.org
> > > > > > > > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > >
> > > >
> >
> >
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] ACPI / memhotplug: Fix a stale pointer in error path
2013-07-12 22:28 ` Toshi Kani
@ 2013-07-12 23:53 ` Rafael J. Wysocki
2013-07-15 16:11 ` Toshi Kani
0 siblings, 1 reply; 12+ messages in thread
From: Rafael J. Wysocki @ 2013-07-12 23:53 UTC (permalink / raw)
To: Toshi Kani; +Cc: Yasuaki Ishimatsu, linux-acpi, linux-kernel
On Friday, July 12, 2013 04:28:36 PM Toshi Kani wrote:
> On Fri, 2013-07-12 at 23:40 +0200, Rafael J. Wysocki wrote:
> > On Friday, July 12, 2013 03:12:24 PM Toshi Kani wrote:
> > > On Fri, 2013-07-12 at 23:13 +0200, Rafael J. Wysocki wrote:
> > > > On Friday, July 12, 2013 03:01:15 PM Toshi Kani wrote:
> > > > > On Fri, 2013-07-12 at 22:42 +0200, Rafael J. Wysocki wrote:
> > > > > > On Friday, July 12, 2013 08:51:29 AM Toshi Kani wrote:
> > > > > > > On Fri, 2013-07-12 at 09:24 +0900, Yasuaki Ishimatsu wrote:
> > > > > > > > (2013/07/11 1:47), Toshi Kani wrote:
> > > > > > > > > device->driver_data needs to be cleared when releasing its data,
> > > > > > > > > mem_device, in an error path of acpi_memory_device_add().
> > > > > > > > >
> > > > > > > > > Signed-off-by: Toshi Kani <toshi.kani@hp.com>
> > > > > > > > > ---
> > > > > > > >
> > > > > > > > Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
> > > > > > >
> > > > > > > Thanks Yasuaki!
> > > > > >
> > > > > > Queued up as a fix for 3.11.
> > > > >
> > > > > Thanks!
> > > > >
> > > > > > Do we need that in -stable as well?
> > > > >
> > > > > Good point. Yes, we need that in -stable as well.
> > > >
> > > > What's the oldest mainline major release that fix is applicable to?
> > >
> > > The fix is applicable all ways up to 2.6.32.
> >
> > For -stable I'll need to say some more about what practical consequences of
> > the bug are. Is it difficult to trigger?
>
> The function evaluates _CRS of memory device objects, and fails when it
> gets an unexpected resource or cannot allocate a memory.
OK, so this is essentially about surviving unexpected external input, which
I suppose is serious enough.
> A kernel crash
> or data corruption may occur when the kernel accessed a stale pointer.
> That said, I am not sure how critical this issue is for old kernels
> since I do not think there are many platforms that support memory
> hotplug today.
Which doesn't matter. People may want to run 3.10.y on future hardware too.
> After reading the recent -stable discussion on LKML, now
> I am not sure if this fix should be applied for -stable.
Well, I don't necessarily agree with some things being said there. I guess
I'll need to say something in that thread. :-)
> I instrumented the kernel to generate an error for testing this change.
OK
Thanks,
Rafael
> > > > > > > > > drivers/acpi/acpi_memhotplug.c | 1 +
> > > > > > > > > 1 file changed, 1 insertion(+)
> > > > > > > > >
> > > > > > > > > diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> > > > > > > > > index c711d11..999adb5 100644
> > > > > > > > > --- a/drivers/acpi/acpi_memhotplug.c
> > > > > > > > > +++ b/drivers/acpi/acpi_memhotplug.c
> > > > > > > > > @@ -323,6 +323,7 @@ static int acpi_memory_device_add(struct acpi_device *device,
> > > > > > > > > /* Get the range from the _CRS */
> > > > > > > > > result = acpi_memory_get_device_resources(mem_device);
> > > > > > > > > if (result) {
> > > > > > > > > + device->driver_data = NULL;
> > > > > > > > > kfree(mem_device);
> > > > > > > > > return result;
> > > > > > > > > }
> > > > > > > > > --
> > > > > > > > > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> > > > > > > > > the body of a message to majordomo@vger.kernel.org
> > > > > > > > > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > >
> > > > >
> > >
> > >
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] ACPI / memhotplug: Fix a stale pointer in error path
2013-07-12 23:53 ` Rafael J. Wysocki
@ 2013-07-15 16:11 ` Toshi Kani
0 siblings, 0 replies; 12+ messages in thread
From: Toshi Kani @ 2013-07-15 16:11 UTC (permalink / raw)
To: Rafael J. Wysocki; +Cc: Yasuaki Ishimatsu, linux-acpi, linux-kernel
On Sat, 2013-07-13 at 01:53 +0200, Rafael J. Wysocki wrote:
> On Friday, July 12, 2013 04:28:36 PM Toshi Kani wrote:
> > On Fri, 2013-07-12 at 23:40 +0200, Rafael J. Wysocki wrote:
> > > On Friday, July 12, 2013 03:12:24 PM Toshi Kani wrote:
> > > > On Fri, 2013-07-12 at 23:13 +0200, Rafael J. Wysocki wrote:
> > > > > On Friday, July 12, 2013 03:01:15 PM Toshi Kani wrote:
> > > > > > On Fri, 2013-07-12 at 22:42 +0200, Rafael J. Wysocki wrote:
> > > > > > > On Friday, July 12, 2013 08:51:29 AM Toshi Kani wrote:
> > > > > > > > On Fri, 2013-07-12 at 09:24 +0900, Yasuaki Ishimatsu wrote:
> > > > > > > > > (2013/07/11 1:47), Toshi Kani wrote:
> > > > > > > > > > device->driver_data needs to be cleared when releasing its data,
> > > > > > > > > > mem_device, in an error path of acpi_memory_device_add().
> > > > > > > > > >
> > > > > > > > > > Signed-off-by: Toshi Kani <toshi.kani@hp.com>
> > > > > > > > > > ---
> > > > > > > > >
> > > > > > > > > Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
> > > > > > > >
> > > > > > > > Thanks Yasuaki!
> > > > > > >
> > > > > > > Queued up as a fix for 3.11.
> > > > > >
> > > > > > Thanks!
> > > > > >
> > > > > > > Do we need that in -stable as well?
> > > > > >
> > > > > > Good point. Yes, we need that in -stable as well.
> > > > >
> > > > > What's the oldest mainline major release that fix is applicable to?
> > > >
> > > > The fix is applicable all ways up to 2.6.32.
> > >
> > > For -stable I'll need to say some more about what practical consequences of
> > > the bug are. Is it difficult to trigger?
> >
> > The function evaluates _CRS of memory device objects, and fails when it
> > gets an unexpected resource or cannot allocate a memory.
>
> OK, so this is essentially about surviving unexpected external input, which
> I suppose is serious enough.
>
> > A kernel crash
> > or data corruption may occur when the kernel accessed a stale pointer.
> > That said, I am not sure how critical this issue is for old kernels
> > since I do not think there are many platforms that support memory
> > hotplug today.
>
> Which doesn't matter. People may want to run 3.10.y on future hardware too.
Good point. Thanks for the clarification!
-Toshi
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2013-07-15 16:12 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-07-10 16:47 [PATCH] ACPI / memhotplug: Fix a stale pointer in error path Toshi Kani
2013-07-12 0:24 ` Yasuaki Ishimatsu
2013-07-12 0:24 ` Yasuaki Ishimatsu
2013-07-12 14:51 ` Toshi Kani
2013-07-12 20:42 ` Rafael J. Wysocki
2013-07-12 21:01 ` Toshi Kani
2013-07-12 21:13 ` Rafael J. Wysocki
2013-07-12 21:12 ` Toshi Kani
2013-07-12 21:40 ` Rafael J. Wysocki
2013-07-12 22:28 ` Toshi Kani
2013-07-12 23:53 ` Rafael J. Wysocki
2013-07-15 16:11 ` Toshi Kani
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.