* [PATCH] drm/amdgpu: fix possible null-pointer dereference in amdgpu_ttm_tt_populate()
@ 2021-07-31 8:04 Tuo Li
2021-08-01 17:19 ` Christian König
0 siblings, 1 reply; 3+ messages in thread
From: Tuo Li @ 2021-07-31 8:04 UTC (permalink / raw)
To: alexander.deucher, christian.koenig, Xinhui.Pan, airlied, daniel,
sumit.semwal, airlied, Felix.Kuehling, Oak.Zeng, nirmoy.das,
tzimmermann, Philip.Yang
Cc: amd-gfx, dri-devel, linux-kernel, linux-media, linaro-mm-sig,
baijiaju1990, Tuo Li, TOTE Robot
The variable ttm is assigned to the variable gtt, and the variable gtt
is checked in:
if (gtt && gtt->userptr)
This indicates that both ttm and gtt can be NULL.
If so, a null-pointer dereference will occur:
if (ttm->page_flags & TTM_PAGE_FLAG_SG)
Also, some null-pointer dereferences will occur in the function
ttm_pool_alloc() which is called in:
return ttm_pool_alloc(&adev->mman.bdev.pool, ttm, ctx);
To fix these possible null-pointer dereferences, the function returns
-EINVAL when ttm is NULL.
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Tuo Li <islituo@gmail.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 3a55f08e00e1..80440f799c09 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1120,8 +1120,11 @@ static int amdgpu_ttm_tt_populate(struct ttm_device *bdev,
struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
struct amdgpu_ttm_tt *gtt = (void *)ttm;
+ if (ttm == NULL)
+ return -EINVAL;
+
/* user pages are bound by amdgpu_ttm_tt_pin_userptr() */
- if (gtt && gtt->userptr) {
+ if (gtt->userptr) {
ttm->sg = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
if (!ttm->sg)
return -ENOMEM;
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] drm/amdgpu: fix possible null-pointer dereference in amdgpu_ttm_tt_populate()
2021-07-31 8:04 [PATCH] drm/amdgpu: fix possible null-pointer dereference in amdgpu_ttm_tt_populate() Tuo Li
@ 2021-08-01 17:19 ` Christian König
2021-08-02 2:47 ` Li Tuo
0 siblings, 1 reply; 3+ messages in thread
From: Christian König @ 2021-08-01 17:19 UTC (permalink / raw)
To: Tuo Li, alexander.deucher, Xinhui.Pan, airlied, daniel,
sumit.semwal, airlied, Felix.Kuehling, Oak.Zeng, nirmoy.das,
tzimmermann, Philip.Yang
Cc: amd-gfx, dri-devel, linux-kernel, linux-media, linaro-mm-sig,
baijiaju1990, TOTE Robot
Am 31.07.21 um 10:04 schrieb Tuo Li:
> The variable ttm is assigned to the variable gtt, and the variable gtt
> is checked in:
> if (gtt && gtt->userptr)
>
> This indicates that both ttm and gtt can be NULL.
> If so, a null-pointer dereference will occur:
> if (ttm->page_flags & TTM_PAGE_FLAG_SG)
>
> Also, some null-pointer dereferences will occur in the function
> ttm_pool_alloc() which is called in:
> return ttm_pool_alloc(&adev->mman.bdev.pool, ttm, ctx);
>
> To fix these possible null-pointer dereferences, the function returns
> -EINVAL when ttm is NULL.
NAK, the NULL test is just a leftover from when the objects where distinct.
Please remove the NULL test instead.
Regards,
Christian.
>
> Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
> Signed-off-by: Tuo Li <islituo@gmail.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 3a55f08e00e1..80440f799c09 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -1120,8 +1120,11 @@ static int amdgpu_ttm_tt_populate(struct ttm_device *bdev,
> struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
> struct amdgpu_ttm_tt *gtt = (void *)ttm;
>
> + if (ttm == NULL)
> + return -EINVAL;
> +
> /* user pages are bound by amdgpu_ttm_tt_pin_userptr() */
> - if (gtt && gtt->userptr) {
> + if (gtt->userptr) {
> ttm->sg = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
> if (!ttm->sg)
> return -ENOMEM;
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] drm/amdgpu: fix possible null-pointer dereference in amdgpu_ttm_tt_populate()
2021-08-01 17:19 ` Christian König
@ 2021-08-02 2:47 ` Li Tuo
0 siblings, 0 replies; 3+ messages in thread
From: Li Tuo @ 2021-08-02 2:47 UTC (permalink / raw)
To: Christian König
Cc: amd-gfx, dri-devel, linux-kernel, airlied, linux-media,
linaro-mm-sig, Xinhui.Pan, baijiaju1990, alexander.deucher,
Philip.Yang, TOTE Robot, sumit.semwal, daniel, Felix.Kuehling,
airlied, Oak.Zeng, nirmoy.das, tzimmermann
Thanks for your feedback! We will remove the null tests according to
your advice and prepare a V2 patch.
Best wishes,
Tuo Li
On 2021/8/2 1:19, Christian König wrote:
> Am 31.07.21 um 10:04 schrieb Tuo Li:
>> The variable ttm is assigned to the variable gtt, and the variable gtt
>> is checked in:
>> if (gtt && gtt->userptr)
>>
>> This indicates that both ttm and gtt can be NULL.
>> If so, a null-pointer dereference will occur:
>> if (ttm->page_flags & TTM_PAGE_FLAG_SG)
>>
>> Also, some null-pointer dereferences will occur in the function
>> ttm_pool_alloc() which is called in:
>> return ttm_pool_alloc(&adev->mman.bdev.pool, ttm, ctx);
>>
>> To fix these possible null-pointer dereferences, the function returns
>> -EINVAL when ttm is NULL.
>
> NAK, the NULL test is just a leftover from when the objects where
> distinct.
>
> Please remove the NULL test instead.
>
> Regards,
> Christian.
>
>>
>> Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
>> Signed-off-by: Tuo Li <islituo@gmail.com>
>> ---
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> index 3a55f08e00e1..80440f799c09 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> @@ -1120,8 +1120,11 @@ static int amdgpu_ttm_tt_populate(struct
>> ttm_device *bdev,
>> struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
>> struct amdgpu_ttm_tt *gtt = (void *)ttm;
>> + if (ttm == NULL)
>> + return -EINVAL;
>> +
>> /* user pages are bound by amdgpu_ttm_tt_pin_userptr() */
>> - if (gtt && gtt->userptr) {
>> + if (gtt->userptr) {
>> ttm->sg = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
>> if (!ttm->sg)
>> return -ENOMEM;
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-07-31 8:04 [PATCH] drm/amdgpu: fix possible null-pointer dereference in amdgpu_ttm_tt_populate() Tuo Li
2021-08-01 17:19 ` Christian König
2021-08-02 2:47 ` Li Tuo
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