[v1 1/4] drm/amdgpu: avoid buffer overflow attach in smu_sys_set_pp_table()

[Jiang Liu <gerry@xxxxxxxxxxxxxxxxx>]

It malicious user provides a small pptable through sysfs and then
a bigger pptable, it may cause buffer overflow attack in function
smu_sys_set_pp_table().

Signed-off-by: Jiang Liu <gerry@xxxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
index 8ca793c222ff..ed9dac00ebfb 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
@@ -612,7 +612,8 @@ static int smu_sys_set_pp_table(void *handle,
 		return -EIO;
 	}
 
-	if (!smu_table->hardcode_pptable) {
+	if (!smu_table->hardcode_pptable || smu_table->power_play_table_size < size) {
+		kfree(smu_table->hardcode_pptable);
 		smu_table->hardcode_pptable = kzalloc(size, GFP_KERNEL);
 		if (!smu_table->hardcode_pptable)
 			return -ENOMEM;
-- 
2.43.5