* [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; 11+ 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] 11+ 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 2013-07-12 14:51 ` Toshi Kani 0 siblings, 1 reply; 11+ 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] 11+ 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 0 siblings, 1 reply; 11+ 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] 11+ 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; 11+ 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] 11+ 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; 11+ 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] 11+ 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; 11+ 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] 11+ 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; 11+ 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] 11+ 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; 11+ 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] 11+ 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; 11+ 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] 11+ 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; 11+ 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] 11+ 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; 11+ 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] 11+ messages in thread
end of thread, other threads:[~2013-07-15 16:12 UTC | newest] Thread overview: 11+ 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 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 a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox