2022-10-29 07:54:39

by Zheng Wang

Subject: [PATCH] drm/nouveau/mmu: fix use-after-free bug in nvkm_vmm_pfn_map

If it failed in kzalloc, vma will be freed in nvkm_vmm_node_merge.
The later use of vma will casue use after free.

Reported-by: Zheng Wang <[email protected]>
Reported-by: Zhuorao Yang <[email protected]>

Fix it by returning to upper caller as soon as error occurs.

Signed-off-by: Zheng Wang <[email protected]>
---
drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
index ae793f400ba1..04befd28f80b 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
@@ -1272,8 +1272,7 @@ nvkm_vmm_pfn_map(struct nvkm_vmm *vmm, u8 shift, u64 addr, u64 size, u64 *pfn)
page -
vmm->func->page, map);
if (WARN_ON(!tmp)) {
- ret = -ENOMEM;
- goto next;
+ return -ENOMEM;
}

if ((tmp->mapped = map))
--
2.25.1

2022-11-02 11:03:59

by Zheng Hacker

Subject: Re: [PATCH] drm/nouveau/mmu: fix use-after-free bug in nvkm_vmm_pfn_map

Friendly Ping :)

2023-03-07 00:05:12

by Lyude Paul

Subject: Re: [PATCH] drm/nouveau/mmu: fix use-after-free bug in nvkm_vmm_pfn_map

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

Will push upstream in a moment

On Sat, 2022-10-29 at 15:46 +0800, Zheng Wang wrote:
> If it failed in kzalloc, vma will be freed in nvkm_vmm_node_merge.
> The later use of vma will casue use after free.
>
> Reported-by: Zheng Wang <[email protected]>
> Reported-by: Zhuorao Yang <[email protected]>
>
> Fix it by returning to upper caller as soon as error occurs.
>
> Signed-off-by: Zheng Wang <[email protected]>
> ---
> drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
> index ae793f400ba1..04befd28f80b 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
> @@ -1272,8 +1272,7 @@ nvkm_vmm_pfn_map(struct nvkm_vmm *vmm, u8 shift, u64 addr, u64 size, u64 *pfn)
> page -
> vmm->func->page, map);
> if (WARN_ON(!tmp)) {
> - ret = -ENOMEM;
> - goto next;
> + return -ENOMEM;
> }
>
> if ((tmp->mapped = map))

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

2023-03-07 00:12:15

by Lyude Paul

Subject: Re: [PATCH] drm/nouveau/mmu: fix use-after-free bug in nvkm_vmm_pfn_map

Actually - could you resend this with [email protected] added to
the cc list just to make patchwork happy?

On Sat, 2022-10-29 at 15:46 +0800, Zheng Wang wrote:
> If it failed in kzalloc, vma will be freed in nvkm_vmm_node_merge.
> The later use of vma will casue use after free.
>
> Reported-by: Zheng Wang <[email protected]>
> Reported-by: Zhuorao Yang <[email protected]>
>
> Fix it by returning to upper caller as soon as error occurs.
>
> Signed-off-by: Zheng Wang <[email protected]>
> ---
> drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
> index ae793f400ba1..04befd28f80b 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
> @@ -1272,8 +1272,7 @@ nvkm_vmm_pfn_map(struct nvkm_vmm *vmm, u8 shift, u64 addr, u64 size, u64 *pfn)
> page -
> vmm->func->page, map);
> if (WARN_ON(!tmp)) {
> - ret = -ENOMEM;
> - goto next;
> + return -ENOMEM;
> }
>
> if ((tmp->mapped = map))

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

2023-03-07 04:25:16

by Zheng Hacker

Subject: Re: [PATCH] drm/nouveau/mmu: fix use-after-free bug in nvkm_vmm_pfn_map

Hi,

This bug has been proved to be a false positive. So there is no need
to make the patch.

Thanks,
Zheng

Lyude Paul <[email protected]> 于2023年3月7日周二 08:11写道：
>
> Actually - could you resend this with [email protected] added to
> the cc list just to make patchwork happy?
>
> On Sat, 2022-10-29 at 15:46 +0800, Zheng Wang wrote:
> > If it failed in kzalloc, vma will be freed in nvkm_vmm_node_merge.
> > The later use of vma will casue use after free.
> >
> > Reported-by: Zheng Wang <[email protected]>
> > Reported-by: Zhuorao Yang <[email protected]>
> >
> > Fix it by returning to upper caller as soon as error occurs.
> >
> > Signed-off-by: Zheng Wang <[email protected]>
> > ---
> > drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
> > index ae793f400ba1..04befd28f80b 100644
> > --- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
> > +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
> > @@ -1272,8 +1272,7 @@ nvkm_vmm_pfn_map(struct nvkm_vmm *vmm, u8 shift, u64 addr, u64 size, u64 *pfn)
> > page -
> > vmm->func->page, map);
> > if (WARN_ON(!tmp)) {
> > - ret = -ENOMEM;
> > - goto next;
> > + return -ENOMEM;
> > }
> >
> > if ((tmp->mapped = map))
>
> --
> Cheers,
> Lyude Paul (she/her)
> Software Engineer at Red Hat
>