2023-01-12 07:57:00

by Xinghui Li

Subject: [PATCH] drm/nouveau/mmu: Fix an UAF issue in NVKM

From: Xinghui Li <[email protected]>

In nvkm_mem_new_host, the mem is be alloced. And mem->memory is
assigned to pmemory. During this process, the mem will be free if
the error occurs. But the *pmemory still points to the &mem->memory
which has been relased.Laterly, the nvkm_memory_unref will put the
memory which points to the pmemory again.So, we set the *pmemory to
NULL to avoid UAF issue.

Reported-by: loydlv <[email protected]>
Signed-off-by: Xinghui Li <[email protected]>
---
drivers/gpu/drm/nouveau/nvkm/subdev/mmu/mem.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/mem.c b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/mem.c
index 92e363dbbc5a..ab30eb1fc0a3 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/mem.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/mem.c
@@ -185,6 +185,7 @@ nvkm_mem_new_host(struct nvkm_mmu *mmu, int type, u8 page, u64 size,
} else
if ( (ret = nvif_unvers(ret, &argv, &argc, args->vn))) {
kfree(mem);
+ *pmemory = NULL;
return ret;
}

--
2.31.1

2023-02-03 09:48:19

by Xinghui Li

Subject: Re: [PATCH] drm/nouveau/mmu: Fix an UAF issue in NVKM

hi all
friendly ping...

<[email protected]> 于2023年1月12日周四 15:18写道：
>
> From: Xinghui Li <[email protected]>
>
> In nvkm_mem_new_host, the mem is be alloced. And mem->memory is
> assigned to pmemory. During this process, the mem will be free if
> the error occurs. But the *pmemory still points to the &mem->memory
> which has been relased.Laterly, the nvkm_memory_unref will put the
> memory which points to the pmemory again.So, we set the *pmemory to
> NULL to avoid UAF issue.
>
> Reported-by: loydlv <[email protected]>
> Signed-off-by: Xinghui Li <[email protected]>
> ---
> drivers/gpu/drm/nouveau/nvkm/subdev/mmu/mem.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/mem.c b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/mem.c
> index 92e363dbbc5a..ab30eb1fc0a3 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/mem.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/mem.c
> @@ -185,6 +185,7 @@ nvkm_mem_new_host(struct nvkm_mmu *mmu, int type, u8 page, u64 size,
> } else
> if ( (ret = nvif_unvers(ret, &argv, &argc, args->vn))) {
> kfree(mem);
> + *pmemory = NULL;
> return ret;
> }
>
> --
> 2.31.1
>