Re: [PATCH][next] drm: fix null pointer dereference on null state pointer

2018-12-24 Thread Daniel Vetter
On Sat, Dec 22, 2018 at 01:00:46PM +, Colin King wrote:
> From: Colin Ian King 
> 
> In the case where state cannot be allocated, the current exit path via
> label 'out' will dereference the null state pointer when calling
> drm_atomic_state_put. Fix this by adding a new error exit label and
> jumping to this to avoid the drm_atomic_state_put.
> 
> Detected by CoverityScan, CID#1476034 ("Dereference after null check")
> 
> Fixes: b9fc5e01d1ce ("drm: Add helper to implement legacy dirtyfb")
> Signed-off-by: Colin Ian King 

Looks correct to me, merged into drm-misc-next-fixes for 4.21.

Thanks, Daniel

> ---
>  drivers/gpu/drm/drm_damage_helper.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_damage_helper.c 
> b/drivers/gpu/drm/drm_damage_helper.c
> index d2a1c7372f36..31032407254d 100644
> --- a/drivers/gpu/drm/drm_damage_helper.c
> +++ b/drivers/gpu/drm/drm_damage_helper.c
> @@ -178,7 +178,7 @@ int drm_atomic_helper_dirtyfb(struct drm_framebuffer *fb,
>   state = drm_atomic_state_alloc(fb->dev);
>   if (!state) {
>   ret = -ENOMEM;
> - goto out;
> + goto out_drop_locks;
>   }
>   state->acquire_ctx = &ctx;
>  
> @@ -238,6 +238,7 @@ int drm_atomic_helper_dirtyfb(struct drm_framebuffer *fb,
>   kfree(rects);
>   drm_atomic_state_put(state);
>  
> +out_drop_locks:
>   drm_modeset_drop_locks(&ctx);
>   drm_modeset_acquire_fini(&ctx);
>  
> -- 
> 2.19.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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[PATCH][next] drm: fix null pointer dereference on null state pointer

2018-12-22 Thread Colin King
From: Colin Ian King 

In the case where state cannot be allocated, the current exit path via
label 'out' will dereference the null state pointer when calling
drm_atomic_state_put. Fix this by adding a new error exit label and
jumping to this to avoid the drm_atomic_state_put.

Detected by CoverityScan, CID#1476034 ("Dereference after null check")

Fixes: b9fc5e01d1ce ("drm: Add helper to implement legacy dirtyfb")
Signed-off-by: Colin Ian King 
---
 drivers/gpu/drm/drm_damage_helper.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_damage_helper.c 
b/drivers/gpu/drm/drm_damage_helper.c
index d2a1c7372f36..31032407254d 100644
--- a/drivers/gpu/drm/drm_damage_helper.c
+++ b/drivers/gpu/drm/drm_damage_helper.c
@@ -178,7 +178,7 @@ int drm_atomic_helper_dirtyfb(struct drm_framebuffer *fb,
state = drm_atomic_state_alloc(fb->dev);
if (!state) {
ret = -ENOMEM;
-   goto out;
+   goto out_drop_locks;
}
state->acquire_ctx = &ctx;
 
@@ -238,6 +238,7 @@ int drm_atomic_helper_dirtyfb(struct drm_framebuffer *fb,
kfree(rects);
drm_atomic_state_put(state);
 
+out_drop_locks:
drm_modeset_drop_locks(&ctx);
drm_modeset_acquire_fini(&ctx);
 
-- 
2.19.1

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