[PATCH 4.9 117/212] drm/radeon: fix array out-of-bounds read and write issues

[Greg Kroah-Hartman]

From: Colin Ian King <colin.k...@canonical.com>

[ Upstream commit 7ee78aff9de13d5dccba133f4a0de5367194b243 ]

There is an off-by-one bounds check on the index into arrays
table->mc_reg_address and table->mc_reg_table_entry[k].mc_data[j] that
can lead to reads and writes outside of arrays. Fix the bound checking
off-by-one error.

Addresses-Coverity: ("Out-of-bounds read/write")
Fixes: cc8dbbb4f62a ("drm/radeon: add dpm support for CI dGPUs (v2)")
Signed-off-by: Colin Ian King <colin.k...@canonical.com>
Signed-off-by: Alex Deucher <alexander.deuc...@amd.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/gpu/drm/radeon/ci_dpm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/radeon/ci_dpm.c b/drivers/gpu/drm/radeon/ci_dpm.c
index be43582811dfc..50bad42527b1c 100644
--- a/drivers/gpu/drm/radeon/ci_dpm.c
+++ b/drivers/gpu/drm/radeon/ci_dpm.c
@@ -4348,7 +4348,7 @@ static int ci_set_mc_special_registers(struct 
radeon_device *rdev,
                                        table->mc_reg_table_entry[k].mc_data[j] 
|= 0x100;
                        }
                        j++;
-                       if (j > SMU7_DISCRETE_MC_REGISTER_ARRAY_SIZE)
+                       if (j >= SMU7_DISCRETE_MC_REGISTER_ARRAY_SIZE)
                                return -EINVAL;
 
                        if (!pi->mem_gddr5) {
-- 
2.25.1