* [PATCH 3.7-rc8] ttm: Fix possible _manager memory allocation oops
@ 2012-12-06 16:20 Tim Gardner
2012-12-06 22:46 ` Dave Airlie
0 siblings, 1 reply; 5+ messages in thread
From: Tim Gardner @ 2012-12-06 16:20 UTC (permalink / raw)
To: linux-kernel
Cc: Tim Gardner, David Airlie, Dave Airlie, Paul E. McKenney,
Zhao Yakui, David Howells, dri-devel
Memory for _manager is allocated using kzalloc() but the result is not checked.
Free _manager on error lest memory become orphaned.
I was led to scrutinize ttm_page_alloc_init() from a smatch warning:
drivers/gpu/drm/ttm/ttm_page_alloc.c:799 ttm_page_alloc_init() error: potential null dereference '_manager'. (kzalloc returns null)
Cc: David Airlie <airlied@linux.ie>
Cc: Dave Airlie <airlied@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Cc: stable@vger.kernel.org # 3.5+
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---
This patch applies to stable 3.5 and newer.
drivers/gpu/drm/ttm/ttm_page_alloc.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
index bd2a3b4..2c73d0a 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
@@ -798,6 +798,10 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
pr_info("Initializing pool allocator\n");
_manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
+ if (!_manager) {
+ pr_err("ttm: Could not allocate _manager.\n");
+ return -ENOMEM;
+ }
ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc");
@@ -817,6 +821,7 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
&glob->kobj, "pool");
if (unlikely(ret != 0)) {
kobject_put(&_manager->kobj);
+ kfree(_manager);
_manager = NULL;
return ret;
}
--
1.7.9.5
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH 3.7-rc8] ttm: Fix possible _manager memory allocation oops
2012-12-06 16:20 [PATCH 3.7-rc8] ttm: Fix possible _manager memory allocation oops Tim Gardner
@ 2012-12-06 22:46 ` Dave Airlie
2012-12-06 23:05 ` Tim Gardner
0 siblings, 1 reply; 5+ messages in thread
From: Dave Airlie @ 2012-12-06 22:46 UTC (permalink / raw)
To: Tim Gardner
Cc: linux-kernel, Paul E. McKenney, dri-devel, David Howells,
Dave Airlie
On Thu, Dec 6, 2012 at 4:20 PM, Tim Gardner <tim.gardner@canonical.com> wrote:
> Memory for _manager is allocated using kzalloc() but the result is not checked.
>
> Free _manager on error lest memory become orphaned.
>
> I was led to scrutinize ttm_page_alloc_init() from a smatch warning:
>
> drivers/gpu/drm/ttm/ttm_page_alloc.c:799 ttm_page_alloc_init() error: potential null dereference '_manager'. (kzalloc returns null)
>
> Cc: David Airlie <airlied@linux.ie>
> Cc: Dave Airlie <airlied@redhat.com>
> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
> Cc: Zhao Yakui <yakui.zhao@intel.com>
> Cc: David Howells <dhowells@redhat.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: stable@vger.kernel.org # 3.5+
> Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
> ---
>
> This patch applies to stable 3.5 and newer.
>
> drivers/gpu/drm/ttm/ttm_page_alloc.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
> index bd2a3b4..2c73d0a 100644
> --- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
> +++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
> @@ -798,6 +798,10 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
> pr_info("Initializing pool allocator\n");
>
> _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
> + if (!_manager) {
> + pr_err("ttm: Could not allocate _manager.\n");
> + return -ENOMEM;
> + }
This is fine,
>
> ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc");
>
> @@ -817,6 +821,7 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
> &glob->kobj, "pool");
> if (unlikely(ret != 0)) {
> kobject_put(&_manager->kobj);
> + kfree(_manager);
> _manager = NULL;
I don;t think this is, since the kobject_put shuold free it.
Dave.
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 3.7-rc8] ttm: Fix possible _manager memory allocation oops
2012-12-06 22:46 ` Dave Airlie
@ 2012-12-06 23:05 ` Tim Gardner
2012-12-07 5:59 ` Dave Airlie
0 siblings, 1 reply; 5+ messages in thread
From: Tim Gardner @ 2012-12-06 23:05 UTC (permalink / raw)
To: Dave Airlie
Cc: linux-kernel, Paul E. McKenney, dri-devel, David Howells,
Dave Airlie
On 12/06/2012 03:46 PM, Dave Airlie wrote:
>>
>> ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc");
>>
>> @@ -817,6 +821,7 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
>> &glob->kobj, "pool");
>> if (unlikely(ret != 0)) {
>> kobject_put(&_manager->kobj);
>> + kfree(_manager);
>> _manager = NULL;
>
> I don;t think this is, since the kobject_put shuold free it.
>
kobject_put only frees memory referenced by kobj, but not the memory
pointed at by _manager.
rtg
--
Tim Gardner tim.gardner@canonical.com
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 3.7-rc8] ttm: Fix possible _manager memory allocation oops
2012-12-06 23:05 ` Tim Gardner
@ 2012-12-07 5:59 ` Dave Airlie
2012-12-07 14:16 ` [PATCH v2 " Tim Gardner
0 siblings, 1 reply; 5+ messages in thread
From: Dave Airlie @ 2012-12-07 5:59 UTC (permalink / raw)
To: Tim Gardner
Cc: linux-kernel, Paul E. McKenney, dri-devel, David Howells,
Dave Airlie
On Fri, Dec 7, 2012 at 9:05 AM, Tim Gardner <tim.gardner@canonical.com> wrote:
> On 12/06/2012 03:46 PM, Dave Airlie wrote:
>
>>>
>>> ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER,
>>> "wc");
>>>
>>> @@ -817,6 +821,7 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob,
>>> unsigned max_pages)
>>> &glob->kobj, "pool");
>>> if (unlikely(ret != 0)) {
>>> kobject_put(&_manager->kobj);
>>> + kfree(_manager);
>>> _manager = NULL;
>>
>>
>> I don;t think this is, since the kobject_put shuold free it.
>>
>
> kobject_put only frees memory referenced by kobj, but not the memory pointed
> at by _manager.
>
The memory pointed at by _manager is the memory freed by the kobj if I
read the code correctly.
Dave.
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH v2 3.7-rc8] ttm: Fix possible _manager memory allocation oops
2012-12-07 5:59 ` Dave Airlie
@ 2012-12-07 14:16 ` Tim Gardner
0 siblings, 0 replies; 5+ messages in thread
From: Tim Gardner @ 2012-12-07 14:16 UTC (permalink / raw)
To: linux-kernel
Cc: Tim Gardner, David Airlie, Dave Airlie, Paul E. McKenney,
Zhao Yakui, David Howells, dri-devel
Memory for _manager is allocated using kzalloc() but the result is not checked.
I was led to scrutinize ttm_page_alloc_init() from a smatch warning:
drivers/gpu/drm/ttm/ttm_page_alloc.c:799 ttm_page_alloc_init() error: potential null dereference '_manager'. (kzalloc returns null)
Cc: David Airlie <airlied@linux.ie>
Cc: Dave Airlie <airlied@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Cc: stable@vger.kernel.org # 3.5+
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---
This patch applies to stable 3.5 and newer.
V2 - kobject_put(&_manager->kobj) uses a destructor and
container_of() to free _mamanger.
drivers/gpu/drm/ttm/ttm_page_alloc.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
index bd2a3b4..c64e96c 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
@@ -798,6 +798,10 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
pr_info("Initializing pool allocator\n");
_manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
+ if (!_manager) {
+ pr_err("ttm: Could not allocate _manager.\n");
+ return -ENOMEM;
+ }
ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc");
--
1.7.9.5
^ permalink raw reply related [flat|nested] 5+ messages in thread
end of thread, other threads:[~2012-12-07 14:16 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2012-12-06 16:20 [PATCH 3.7-rc8] ttm: Fix possible _manager memory allocation oops Tim Gardner
2012-12-06 22:46 ` Dave Airlie
2012-12-06 23:05 ` Tim Gardner
2012-12-07 5:59 ` Dave Airlie
2012-12-07 14:16 ` [PATCH v2 " Tim Gardner
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