[PATCH] drm: amd: Fix potential NULL pointer dereference in atomctrl_get_smc_sclk_range_table

[Ivan Stepchenko <sid@itb.spb.ru>]

The function atomctrl_get_smc_sclk_range_table() does not check the return
value of smu_atom_get_data_table(). If smu_atom_get_data_table() fails to
retrieve SMU_Info table, it returns NULL which is later dereferenced.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: a23eefa2f461 ("drm/amd/powerplay: enable dpm for baffin.")
Cc: stable@vger.kernel.org
Signed-off-by: Ivan Stepchenko <sid@itb.spb.ru>
---
 drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppatomctrl.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppatomctrl.c b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppatomctrl.c
index fe24219c3bf4..4bd92fd782be 100644
--- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppatomctrl.c
+++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppatomctrl.c
@@ -992,6 +992,8 @@ int atomctrl_get_smc_sclk_range_table(struct pp_hwmgr *hwmgr, struct pp_atom_ctr
 			GetIndexIntoMasterTable(DATA, SMU_Info),
 			&size, &frev, &crev);
 
+	if (!psmu_info)
+		return -EINVAL;
 
 	for (i = 0; i < psmu_info->ucSclkEntryNum; i++) {
 		table->entry[i].ucVco_setting = psmu_info->asSclkFcwRangeEntry[i].ucVco_setting;
-- 
2.34.1