From: YuBiao Wang Date: Wed, 24 Aug 2022 07:56:04 +0000 (+0800) Subject: drm/amdgpu: Fix use-after-free in amdgpu_cs_ioctl X-Git-Tag: v6.6.17~6361^2~19^2~101 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2581c5d85e31c96dee352a751dbce17c1b71b417;p=platform%2Fkernel%2Flinux-rpi.git drm/amdgpu: Fix use-after-free in amdgpu_cs_ioctl [Why] In amdgpu_cs_ioctl, amdgpu_job_free could be performed ealier if there is -ERESTARTSYS error. In this case, job->hw_fence could be not initialized yet. Putting hw_fence during amdgpu_job_free could lead to a use-after-free warning. [How] Check if drm_sched_job_init is performed before job_free by checking s_fence. v2: Check hw_fence.ops instead since it could be NULL if fence is not initialized. Reverse the condition since !=NULL check is discouraged in kernel. Signed-off-by: YuBiao Wang Reviewed-by: Andrey Grodzovsky Signed-off-by: Alex Deucher --- diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c index 8f51adf..1062b7e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c @@ -162,7 +162,10 @@ void amdgpu_job_free(struct amdgpu_job *job) amdgpu_sync_free(&job->sync); amdgpu_sync_free(&job->sched_sync); - dma_fence_put(&job->hw_fence); + if (!job->hw_fence.ops) + kfree(job); + else + dma_fence_put(&job->hw_fence); } int amdgpu_job_submit(struct amdgpu_job *job, struct drm_sched_entity *entity,