Re: [PATCH] drm/amdkfd: Fix memory leak in kfd_mem_dmamap_userptr()

[Felix Kuehling]

On 2022-10-17 21:27, Rafael Mendonca wrote:

If the number of pages from the userptr BO differs from the SG BO then the
allocated memory for the SG table doesn't get freed before returning
-EINVAL, which may lead to a memory leak in some error paths. Fix this by
checking the number of pages before allocating memory for the SG table.

Fixes: 264fb4d332f5 ("drm/amdgpu: Add multi-GPU DMA mapping helpers")
Signed-off-by: Rafael Mendonca 


Thank you for catching this. The patch is

Reviewed-by: Felix Kuehling 

I submitted it to our amd-staging-drm-next branch.

Regards,
  Felix



---
  drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 6 +++---
  1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 978d3970b5cc..84f44f7e4111 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -510,13 +510,13 @@ kfd_mem_dmamap_userptr(struct kgd_mem *mem,
struct ttm_tt *ttm = bo->tbo.ttm;
int ret;
  
+	if (WARN_ON(ttm->num_pages != src_ttm->num_pages))

+   return -EINVAL;
+
ttm->sg = kmalloc(sizeof(*ttm->sg), GFP_KERNEL);
if (unlikely(!ttm->sg))
return -ENOMEM;
  
-	if (WARN_ON(ttm->num_pages != src_ttm->num_pages))

-   return -EINVAL;
-
/* Same sequence as in amdgpu_ttm_tt_pin_userptr */
ret = sg_alloc_table_from_pages(ttm->sg, src_ttm->pages,
ttm->num_pages, 0,

[PATCH] drm/amdkfd: Fix memory leak in kfd_mem_dmamap_userptr()

[Rafael Mendonca]

If the number of pages from the userptr BO differs from the SG BO then the
allocated memory for the SG table doesn't get freed before returning
-EINVAL, which may lead to a memory leak in some error paths. Fix this by
checking the number of pages before allocating memory for the SG table.

Fixes: 264fb4d332f5 ("drm/amdgpu: Add multi-GPU DMA mapping helpers")
Signed-off-by: Rafael Mendonca 
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 978d3970b5cc..84f44f7e4111 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -510,13 +510,13 @@ kfd_mem_dmamap_userptr(struct kgd_mem *mem,
struct ttm_tt *ttm = bo->tbo.ttm;
int ret;
 
+   if (WARN_ON(ttm->num_pages != src_ttm->num_pages))
+   return -EINVAL;
+
ttm->sg = kmalloc(sizeof(*ttm->sg), GFP_KERNEL);
if (unlikely(!ttm->sg))
return -ENOMEM;
 
-   if (WARN_ON(ttm->num_pages != src_ttm->num_pages))
-   return -EINVAL;
-
/* Same sequence as in amdgpu_ttm_tt_pin_userptr */
ret = sg_alloc_table_from_pages(ttm->sg, src_ttm->pages,
ttm->num_pages, 0,
-- 
2.34.1