[PATCH 4.19 263/338] drm/amd/amdgpu/amdgpu_cs: fix refcount leak of a dma_fence obj

Greg Kroah-Hartman
2022-04-14T14:11:11Z

From: Xin Xiong <xiongx18@fudan.edu.cn>

[ Upstream commit dfced44f122c500004a48ecc8db516bb6a295a1b ]

This issue takes place in an error path in
amdgpu_cs_fence_to_handle_ioctl(). When `info->in.what` falls into
default case, the function simply returns -EINVAL, forgetting to
decrement the reference count of a dma_fence obj, which is bumped
earlier by amdgpu_cs_get_fence(). This may result in reference count
leaks.

Fix it by decreasing the refcount of specific object before returning
the error code.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 81001d879322..023309296bfc 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -1469,6 +1469,7 @@ int amdgpu_cs_fence_to_handle_ioctl(struct drm_device *dev, void *data,
return 0;

default:
+ dma_fence_put(fence);
return -EINVAL;
}
}
--
2.35.1