[PATCH AUTOSEL 6.11 162/244] drm/amdgpu: add list empty check to avoid null pointer issue

Sasha Levin
2024-09-25T11:47:39Z

From: Yang Wang <kevinyang.wang@amd.com>

[ Upstream commit 4416377ae1fdc41a90b665943152ccd7ff61d3c5 ]

Add list empty check to avoid null pointer issues in some corner cases.
- list_for_each_entry_safe()

Signed-off-by: Yang Wang <kevinyang.wang@amd.com>
Reviewed-by: Tao Zhou <tao.zhou1@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_aca.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_aca.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_aca.c
index 19158cc30f31f..43f3e72fb247a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_aca.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_aca.c
@@ -80,6 +80,9 @@ static void aca_banks_release(struct aca_banks *banks)
{
struct aca_bank_node *node, *tmp;

+ if (list_empty(&banks->list))
+ return;
+
list_for_each_entry_safe(node, tmp, &banks->list, node) {
list_del(&node->node);
kvfree(node);
@@ -562,9 +565,13 @@ static void aca_error_fini(struct aca_error *aerr)
struct aca_bank_error *bank_error, *tmp;

mutex_lock(&aerr->lock);
+ if (list_empty(&aerr->list))
+ goto out_unlock;
+
list_for_each_entry_safe(bank_error, tmp, &aerr->list, node)
aca_bank_error_remove(aerr, bank_error);

+out_unlock:
mutex_destroy(&aerr->lock);
}

@@ -680,6 +687,9 @@ static void aca_manager_fini(struct aca_handle_manager *mgr)
{
struct aca_handle *handle, *tmp;

+ if (list_empty(&mgr->list))
+ return;
+
list_for_each_entry_safe(handle, tmp, &mgr->list, node)
amdgpu_aca_remove_handle(handle);
}
--
2.43.0