2020-12-03 00:08:05

by Jeremy Cline

Subject: [PATCH] drm/nouveau: avoid a use-after-free when BO init fails

nouveau_bo_init() is backed by ttm_bo_init() and ferries its return code
back to the caller. On failures, ttm_bo_init() invokes the provided
destructor which should de-initialize and free the memory.

Thus, when nouveau_bo_init() returns an error the gem object has already
been released and the memory freed by nouveau_bo_del_ttm().

Fixes: 019cbd4a4feb ("drm/nouveau: Initialize GEM object before TTM object")
Cc: Thierry Reding <[email protected]>
Signed-off-by: Jeremy Cline <[email protected]>
---
drivers/gpu/drm/nouveau/nouveau_gem.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index 787d05eefd9c..d30157cc7169 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -211,10 +211,8 @@ nouveau_gem_new(struct nouveau_cli *cli, u64 size, int align, uint32_t domain,
}

ret = nouveau_bo_init(nvbo, size, align, domain, NULL, NULL);
- if (ret) {
- nouveau_bo_ref(NULL, &nvbo);
+ if (ret)
return ret;
- }

/* we restrict allowed domains on nv50+ to only the types
* that were requested at creation time. not possibly on
--
2.28.0

2021-03-26 21:44:48

by Lyude Paul

Subject: Re: [PATCH] drm/nouveau: avoid a use-after-free when BO init fails

Reviewed-by: Lyude Paul <[email protected]>

On Wed, 2020-12-02 at 19:02 -0500, Jeremy Cline wrote:
> nouveau_bo_init() is backed by ttm_bo_init() and ferries its return code
> back to the caller. On failures, ttm_bo_init() invokes the provided
> destructor which should de-initialize and free the memory.
>
> Thus, when nouveau_bo_init() returns an error the gem object has already
> been released and the memory freed by nouveau_bo_del_ttm().
>
> Fixes: 019cbd4a4feb ("drm/nouveau: Initialize GEM object before TTM object")
> Cc: Thierry Reding <[email protected]>
> Signed-off-by: Jeremy Cline <[email protected]>
> ---
>  drivers/gpu/drm/nouveau/nouveau_gem.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c
> b/drivers/gpu/drm/nouveau/nouveau_gem.c
> index 787d05eefd9c..d30157cc7169 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_gem.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
> @@ -211,10 +211,8 @@ nouveau_gem_new(struct nouveau_cli *cli, u64 size, int
> align, uint32_t domain,
>         }
>  
>         ret = nouveau_bo_init(nvbo, size, align, domain, NULL, NULL);
> -       if (ret) {
> -               nouveau_bo_ref(NULL, &nvbo);
> +       if (ret)
>                 return ret;
> -       }
>  
>         /* we restrict allowed domains on nv50+ to only the types
>          * that were requested at creation time.  not possibly on

--
Sincerely,
Lyude Paul (she/her)
Software Engineer at Red Hat

Note: I deal with a lot of emails and have a lot of bugs on my plate. If you've
asked me a question, are waiting for a review/merge on a patch, etc. and I
haven't responded in a while, please feel free to send me another email to check
on my status. I don't bite!

2021-09-28 11:09:06

by Karol Herbst

Subject: Re: [PATCH] drm/nouveau: avoid a use-after-free when BO init fails

Reviewed-by: Karol Herbst <[email protected]>

and queued

On Fri, Mar 26, 2021 at 10:41 PM Lyude Paul <[email protected]> wrote:
>
> Reviewed-by: Lyude Paul <[email protected]>
>
> On Wed, 2020-12-02 at 19:02 -0500, Jeremy Cline wrote:
> > nouveau_bo_init() is backed by ttm_bo_init() and ferries its return code
> > back to the caller. On failures, ttm_bo_init() invokes the provided
> > destructor which should de-initialize and free the memory.
> >
> > Thus, when nouveau_bo_init() returns an error the gem object has already
> > been released and the memory freed by nouveau_bo_del_ttm().
> >
> > Fixes: 019cbd4a4feb ("drm/nouveau: Initialize GEM object before TTM object")
> > Cc: Thierry Reding <[email protected]>
> > Signed-off-by: Jeremy Cline <[email protected]>
> > ---
> > drivers/gpu/drm/nouveau/nouveau_gem.c | 4 +---
> > 1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c
> > b/drivers/gpu/drm/nouveau/nouveau_gem.c
> > index 787d05eefd9c..d30157cc7169 100644
> > --- a/drivers/gpu/drm/nouveau/nouveau_gem.c
> > +++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
> > @@ -211,10 +211,8 @@ nouveau_gem_new(struct nouveau_cli *cli, u64 size, int
> > align, uint32_t domain,
> > }
> >
> > ret = nouveau_bo_init(nvbo, size, align, domain, NULL, NULL);
> > - if (ret) {
> > - nouveau_bo_ref(NULL, &nvbo);
> > + if (ret)
> > return ret;
> > - }
> >
> > /* we restrict allowed domains on nv50+ to only the types
> > * that were requested at creation time. not possibly on
>
> --
> Sincerely,
> Lyude Paul (she/her)
> Software Engineer at Red Hat
>
> Note: I deal with a lot of emails and have a lot of bugs on my plate. If you've
> asked me a question, are waiting for a review/merge on a patch, etc. and I
> haven't responded in a while, please feel free to send me another email to check
> on my status. I don't bite!
>
> _______________________________________________
> dri-devel mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel