2021-12-09 06:51:53

by Jianglei Nie

[permalink] [raw]
Subject: [PATCH] drm/amdgpu: Fix reference leak in psp_xgmi_reflect_topology_info()

In line 1138 (#1), amdgpu_get_xgmi_hive() increases the kobject reference
counter of the hive it returned. The hive returned by
amdgpu_get_xgmi_hive()should be released with the help of
amdgpu_put_xgmi_hive() to balance its kobject reference counter properly.
Forgetting the amdgpu_put_xgmi_hive() operation will result in reference
leak.

We can fix it by calling amdgpu_put_xgmi_hive() before the end of the
function (#2).

1128 static void psp_xgmi_reflect_topology_info(struct psp_context *psp,
1129 struct psp_xgmi_node_info node_info)
1130 {

1138 hive = amdgpu_get_xgmi_hive(psp->adev);
// #1: kzalloc space reference increment
1139 list_for_each_entry(mirror_adev, &hive->device_list, gmc.xgmi.head) {
1140 struct psp_xgmi_topology_info *mirror_top_info;
1141 int j;

1143 if (mirror_adev->gmc.xgmi.node_id != dst_node_id)
1144 continue;

1146 mirror_top_info = &mirror_adev->psp.xgmi_context.top_info;
1147 for (j = 0; j < mirror_top_info->num_nodes; j++) {
1148 if (mirror_top_info->nodes[j].node_id != src_node_id)
1149 continue;

1151 mirror_top_info->nodes[j].num_hops = dst_num_hops;

1157 if (dst_num_links)
1158 mirror_top_info->nodes[j].num_links = dst_num_links;

1160 break;
1161 }

1163 break;
1164 }
// #2: missing reference decrement
1165 }

Signed-off-by: Jianglei Nie <[email protected]>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
index c641f84649d6..f6362047ed71 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
@@ -1162,6 +1162,7 @@ static void psp_xgmi_reflect_topology_info(struct psp_context *psp,

break;
}
+ amdgpu_put_xgmi_hive(hive);
}

int psp_xgmi_get_topology_info(struct psp_context *psp,
--
2.25.1