[PATCH 4.18 209/235] drm/amdkfd: Fix error codes in kfd_get_process

[Greg Kroah-Hartman]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Wei Lu <wei.lu2@xxxxxxx>

[ Upstream commit e47cb828eb3fca3e8999a0b9aa053dda18552071 ]

Return ERR_PTR(-EINVAL) if kfd_get_process fails to find the process.
This fixes kernel oopses when a child process calls KFD ioctls with
a file descriptor inherited from the parent process.

Signed-off-by: Wei Lu <wei.lu2@xxxxxxx>
Reviewed-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Signed-off-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Acked-by: Christian KÃnig <christian.koenig@xxxxxxx>
Signed-off-by: Oded Gabbay <oded.gabbay@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/amd/amdkfd/kfd_process.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -244,6 +244,8 @@ struct kfd_process *kfd_get_process(cons
 		return ERR_PTR(-EINVAL);
 
 	process = find_process(thread);
+	if (!process)
+		return ERR_PTR(-EINVAL);
 
 	return process;
 }