2023-02-15 23:50:35

by Rob Clark

Subject: [PATCH] drm/msm: Fix potential invalid ptr free

From: Rob Clark <[email protected]>

The error path cleanup expects that chain and syncobj are either NULL or
valid pointers. But post_deps was not allocated with __GFP_ZERO.

Fixes: ab723b7a992a ("drm/msm: Add syncobj support.")
Signed-off-by: Rob Clark <[email protected]>
---
drivers/gpu/drm/msm/msm_gem_submit.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 6503220e5a4b..e4d13540300e 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -640,8 +640,8 @@ static struct msm_submit_post_dep *msm_parse_post_deps(struct drm_device *dev,
int ret = 0;
uint32_t i, j;

- post_deps = kmalloc_array(nr_syncobjs, sizeof(*post_deps),
- GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
+ post_deps = kcalloc(nr_syncobjs, sizeof(*post_deps),
+ GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
if (!post_deps)
return ERR_PTR(-ENOMEM);

@@ -656,7 +656,6 @@ static struct msm_submit_post_dep *msm_parse_post_deps(struct drm_device *dev,
}

post_deps[i].point = syncobj_desc.point;
- post_deps[i].chain = NULL;

if (syncobj_desc.flags) {
ret = -EINVAL;
--
2.39.1

2023-02-16 16:41:58

by Dmitry Baryshkov

Subject: Re: [PATCH] drm/msm: Fix potential invalid ptr free

On 16/02/2023 01:50, Rob Clark wrote:
> From: Rob Clark <[email protected]>
>
> The error path cleanup expects that chain and syncobj are either NULL or
> valid pointers. But post_deps was not allocated with __GFP_ZERO.
>
> Fixes: ab723b7a992a ("drm/msm: Add syncobj support.")
> Signed-off-by: Rob Clark <[email protected]>

Reviewed-by: Dmitry Baryshkov <[email protected]>

This makes me want to rewrite the ab723b7a992a ("drm/msm: Add syncobj
support.") in the usual explicit-error-path way. WDYT?

> ---
> drivers/gpu/drm/msm/msm_gem_submit.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
> index 6503220e5a4b..e4d13540300e 100644
> --- a/drivers/gpu/drm/msm/msm_gem_submit.c
> +++ b/drivers/gpu/drm/msm/msm_gem_submit.c
> @@ -640,8 +640,8 @@ static struct msm_submit_post_dep *msm_parse_post_deps(struct drm_device *dev,
> int ret = 0;
> uint32_t i, j;
>
> - post_deps = kmalloc_array(nr_syncobjs, sizeof(*post_deps),
> - GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
> + post_deps = kcalloc(nr_syncobjs, sizeof(*post_deps),
> + GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
> if (!post_deps)
> return ERR_PTR(-ENOMEM);
>
> @@ -656,7 +656,6 @@ static struct msm_submit_post_dep *msm_parse_post_deps(struct drm_device *dev,
> }
>
> post_deps[i].point = syncobj_desc.point;
> - post_deps[i].chain = NULL;
>
> if (syncobj_desc.flags) {
> ret = -EINVAL;

--
With best wishes
Dmitry

2023-02-16 17:16:20

by Dmitry Osipenko

Subject: Re: [PATCH] drm/msm: Fix potential invalid ptr free

On 2/16/23 02:50, Rob Clark wrote:
> From: Rob Clark <[email protected]>
>
> The error path cleanup expects that chain and syncobj are either NULL or
> valid pointers. But post_deps was not allocated with __GFP_ZERO.
>
> Fixes: ab723b7a992a ("drm/msm: Add syncobj support.")
> Signed-off-by: Rob Clark <[email protected]>
> ---
> drivers/gpu/drm/msm/msm_gem_submit.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
> index 6503220e5a4b..e4d13540300e 100644
> --- a/drivers/gpu/drm/msm/msm_gem_submit.c
> +++ b/drivers/gpu/drm/msm/msm_gem_submit.c
> @@ -640,8 +640,8 @@ static struct msm_submit_post_dep *msm_parse_post_deps(struct drm_device *dev,
> int ret = 0;
> uint32_t i, j;
>
> - post_deps = kmalloc_array(nr_syncobjs, sizeof(*post_deps),
> - GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
> + post_deps = kcalloc(nr_syncobjs, sizeof(*post_deps),
> + GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
> if (!post_deps)
> return ERR_PTR(-ENOMEM);
>
> @@ -656,7 +656,6 @@ static struct msm_submit_post_dep *msm_parse_post_deps(struct drm_device *dev,
> }
>
> post_deps[i].point = syncobj_desc.point;
> - post_deps[i].chain = NULL;
>
> if (syncobj_desc.flags) {
> ret = -EINVAL;

Good catch!

Reviewed-by: Dmitry Osipenko <[email protected]>

--
Best regards,
Dmitry