From 0317d73954850c48268f3db00a49e676d12b10cf Mon Sep 17 00:00:00 2001
From: "Stanley.Yang" <Stanley.Yang@amd.com>
Date: Wed, 16 Nov 2022 17:08:22 +0800
Subject: drm/amdgpu: fix use-after-free during gpu recovery
[Why]
[ 754.862560] refcount_t: underflow; use-after-free.
[ 754.862898] Call Trace:
[ 754.862903] <TASK>
[ 754.862913] amdgpu_job_free_cb+0xc2/0xe1 [amdgpu]
[ 754.863543] drm_sched_main.cold+0x34/0x39 [amd_sched]
[How]
The fw_fence may be not init, check whether dma_fence_init
is performed before job free
Signed-off-by: Stanley.Yang <Stanley.Yang@amd.com>
Reviewed-by: Tao Zhou <tao.zhou1@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_job.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
index 032651a655f0..7f1ca90a552c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
@@ -174,7 +174,12 @@ static void amdgpu_job_free_cb(struct drm_sched_job *s_job)
drm_sched_job_cleanup(s_job);
amdgpu_sync_free(&job->explicit_sync);
- dma_fence_put(&job->hw_fence);
+
+ /* only put the hw fence if has embedded fence */
+ if (!job->hw_fence.ops)
+ kfree(job);
+ else
+ dma_fence_put(&job->hw_fence);
}
void amdgpu_job_set_gang_leader(struct amdgpu_job *job,
--
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