[PATCH 4.19 069/168] drm/radeon: fix array out-of-bounds read and write issues

Greg Kroah-Hartman
2020-08-17T17:44:24Z

From: Colin Ian King <colin.king@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.king@canonical.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@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 9e7d5e44a12fa..90c1afe498bea 100644
--- a/drivers/gpu/drm/radeon/ci_dpm.c
+++ b/drivers/gpu/drm/radeon/ci_dpm.c
@@ -4364,7 +4364,7 @@ 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