* [PATCH v2] dma-buf: fix an error pointer vs NULL bug
@ 2023-07-06 12:37 Dan Carpenter
2023-07-06 12:54 ` Christian König
0 siblings, 1 reply; 3+ messages in thread
From: Dan Carpenter @ 2023-07-06 12:37 UTC (permalink / raw)
To: Sumit Semwal
Cc: kernel-janitors, Gustavo Padovan, Maxime Ripard, linaro-mm-sig,
dri-devel, Thomas Zimmermann, Christian König, linux-media
Smatch detected potential error pointer dereference.
drivers/gpu/drm/drm_syncobj.c:888 drm_syncobj_transfer_to_timeline()
error: 'fence' dereferencing possible ERR_PTR()
The error pointer comes from dma_fence_allocate_private_stub(). One
caller expected error pointers and one expected NULL pointers. Change
it to return NULL and update the caller which expected error pointers,
drm_syncobj_assign_null_handle(), to check for NULL instead.
Fixes: f781f661e8c9 ("dma-buf: keep the signaling time of merged fences v3")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
v2: Fix it in dma_fence_allocate_private_stub() instead of
__dma_fence_unwrap_merge().
drivers/dma-buf/dma-fence.c | 2 +-
drivers/gpu/drm/drm_syncobj.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index ad076f208760..8aa8f8cb7071 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -160,7 +160,7 @@ struct dma_fence *dma_fence_allocate_private_stub(ktime_t timestamp)
fence = kzalloc(sizeof(*fence), GFP_KERNEL);
if (fence == NULL)
- return ERR_PTR(-ENOMEM);
+ return NULL;
dma_fence_init(fence,
&dma_fence_stub_ops,
diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
index 04589a35eb09..e592c5da70ce 100644
--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -355,8 +355,8 @@ static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
{
struct dma_fence *fence = dma_fence_allocate_private_stub(ktime_get());
- if (IS_ERR(fence))
- return PTR_ERR(fence);
+ if (!fence)
+ return -ENOMEM;
drm_syncobj_replace_fence(syncobj, fence);
dma_fence_put(fence);
--
2.39.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] dma-buf: fix an error pointer vs NULL bug
2023-07-06 12:37 [PATCH v2] dma-buf: fix an error pointer vs NULL bug Dan Carpenter
@ 2023-07-06 12:54 ` Christian König
2023-07-06 14:13 ` Sumit Semwal
0 siblings, 1 reply; 3+ messages in thread
From: Christian König @ 2023-07-06 12:54 UTC (permalink / raw)
To: Dan Carpenter, Sumit Semwal
Cc: kernel-janitors, Thomas Zimmermann, Gustavo Padovan,
Maxime Ripard, linaro-mm-sig, dri-devel, linux-media
Am 06.07.23 um 14:37 schrieb Dan Carpenter:
> Smatch detected potential error pointer dereference.
>
> drivers/gpu/drm/drm_syncobj.c:888 drm_syncobj_transfer_to_timeline()
> error: 'fence' dereferencing possible ERR_PTR()
>
> The error pointer comes from dma_fence_allocate_private_stub(). One
> caller expected error pointers and one expected NULL pointers. Change
> it to return NULL and update the caller which expected error pointers,
> drm_syncobj_assign_null_handle(), to check for NULL instead.
>
> Fixes: f781f661e8c9 ("dma-buf: keep the signaling time of merged fences v3")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Christian König <christian.koenig@amd.com>
Should I push that one to drm-misc-fixes?
Regards,
Christian.
> ---
> v2: Fix it in dma_fence_allocate_private_stub() instead of
> __dma_fence_unwrap_merge().
>
>
> drivers/dma-buf/dma-fence.c | 2 +-
> drivers/gpu/drm/drm_syncobj.c | 4 ++--
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
> index ad076f208760..8aa8f8cb7071 100644
> --- a/drivers/dma-buf/dma-fence.c
> +++ b/drivers/dma-buf/dma-fence.c
> @@ -160,7 +160,7 @@ struct dma_fence *dma_fence_allocate_private_stub(ktime_t timestamp)
>
> fence = kzalloc(sizeof(*fence), GFP_KERNEL);
> if (fence == NULL)
> - return ERR_PTR(-ENOMEM);
> + return NULL;
>
> dma_fence_init(fence,
> &dma_fence_stub_ops,
> diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> index 04589a35eb09..e592c5da70ce 100644
> --- a/drivers/gpu/drm/drm_syncobj.c
> +++ b/drivers/gpu/drm/drm_syncobj.c
> @@ -355,8 +355,8 @@ static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
> {
> struct dma_fence *fence = dma_fence_allocate_private_stub(ktime_get());
>
> - if (IS_ERR(fence))
> - return PTR_ERR(fence);
> + if (!fence)
> + return -ENOMEM;
>
> drm_syncobj_replace_fence(syncobj, fence);
> dma_fence_put(fence);
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] dma-buf: fix an error pointer vs NULL bug
2023-07-06 12:54 ` Christian König
@ 2023-07-06 14:13 ` Sumit Semwal
0 siblings, 0 replies; 3+ messages in thread
From: Sumit Semwal @ 2023-07-06 14:13 UTC (permalink / raw)
To: Christian König
Cc: kernel-janitors, Gustavo Padovan, Maxime Ripard, linaro-mm-sig,
dri-devel, Thomas Zimmermann, Dan Carpenter, linux-media
On Thu, 6 Jul 2023 at 18:24, Christian König <christian.koenig@amd.com> wrote:
>
> Am 06.07.23 um 14:37 schrieb Dan Carpenter:
> > Smatch detected potential error pointer dereference.
> >
> > drivers/gpu/drm/drm_syncobj.c:888 drm_syncobj_transfer_to_timeline()
> > error: 'fence' dereferencing possible ERR_PTR()
> >
> > The error pointer comes from dma_fence_allocate_private_stub(). One
> > caller expected error pointers and one expected NULL pointers. Change
> > it to return NULL and update the caller which expected error pointers,
> > drm_syncobj_assign_null_handle(), to check for NULL instead.
> >
> > Fixes: f781f661e8c9 ("dma-buf: keep the signaling time of merged fences v3")
> > Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
>
Thanks for catching this!
> Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Sumit Semwal <sumit.semwal@linaro.org>
>
> Should I push that one to drm-misc-fixes?
If you haven't pushed already, I can push it now.
>
> Regards,
> Christian.
Best,
Sumit.
>
> > ---
> > v2: Fix it in dma_fence_allocate_private_stub() instead of
> > __dma_fence_unwrap_merge().
> >
> >
> > drivers/dma-buf/dma-fence.c | 2 +-
> > drivers/gpu/drm/drm_syncobj.c | 4 ++--
> > 2 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
> > index ad076f208760..8aa8f8cb7071 100644
> > --- a/drivers/dma-buf/dma-fence.c
> > +++ b/drivers/dma-buf/dma-fence.c
> > @@ -160,7 +160,7 @@ struct dma_fence *dma_fence_allocate_private_stub(ktime_t timestamp)
> >
> > fence = kzalloc(sizeof(*fence), GFP_KERNEL);
> > if (fence == NULL)
> > - return ERR_PTR(-ENOMEM);
> > + return NULL;
> >
> > dma_fence_init(fence,
> > &dma_fence_stub_ops,
> > diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> > index 04589a35eb09..e592c5da70ce 100644
> > --- a/drivers/gpu/drm/drm_syncobj.c
> > +++ b/drivers/gpu/drm/drm_syncobj.c
> > @@ -355,8 +355,8 @@ static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
> > {
> > struct dma_fence *fence = dma_fence_allocate_private_stub(ktime_get());
> >
> > - if (IS_ERR(fence))
> > - return PTR_ERR(fence);
> > + if (!fence)
> > + return -ENOMEM;
> >
> > drm_syncobj_replace_fence(syncobj, fence);
> > dma_fence_put(fence);
>
--
Thanks and regards,
Sumit Semwal (he / him)
Tech Lead - LCG, Vertical Technologies
Linaro.org │ Open source software for ARM SoCs
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-07-06 12:54 ` Christian König
2023-07-06 14:13 ` Sumit Semwal
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