From 0b40c854ee240dc1e3bd8245d14827abbf7a4a5a Mon Sep 17 00:00:00 2001
From: Alexey Kodanev <aleksei.kodanev@bell-sw.com>
Date: Mon, 6 Jun 2022 16:50:54 +0300
Subject: drm/radeon: fix potential buffer overflow in
ni_set_mc_special_registers()
Git-commit: 136f614931a2bb73616b292cf542da3a18daefd5
Patch-mainline: v6.0-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225 jsc#PED-2849
The last case label can write two buffers 'mc_reg_address[j]' and
'mc_data[j]' with 'j' offset equal to SMC_NISLANDS_MC_REGISTER_ARRAY_SIZE
since there are no checks for this value in both case labels after the
last 'j++'.
Instead of changing '>' to '>=' there, add the bounds check at the start
of the second 'case' (the first one already has it).
Also, remove redundant last checks for 'j' index bigger than array size.
The expression is always false. Moreover, before or after the patch
'table->last' can be equal to SMC_NISLANDS_MC_REGISTER_ARRAY_SIZE and it
seems it can be a valid value.
Detected using the static analysis tool - Svace.
Fixes: 69e0b57a91ad ("drm/radeon/kms: add dpm support for cayman (v5)")
Signed-off-by: Alexey Kodanev <aleksei.kodanev@bell-sw.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/radeon/ni_dpm.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/radeon/ni_dpm.c b/drivers/gpu/drm/radeon/ni_dpm.c
index 769f666335ac..672d2239293e 100644
--- a/drivers/gpu/drm/radeon/ni_dpm.c
+++ b/drivers/gpu/drm/radeon/ni_dpm.c
@@ -2741,10 +2741,10 @@ static int ni_set_mc_special_registers(struct radeon_device *rdev,
table->mc_reg_table_entry[k].mc_data[j] |= 0x100;
}
j++;
- if (j > SMC_NISLANDS_MC_REGISTER_ARRAY_SIZE)
- return -EINVAL;
break;
case MC_SEQ_RESERVE_M >> 2:
+ if (j >= SMC_NISLANDS_MC_REGISTER_ARRAY_SIZE)
+ return -EINVAL;
temp_reg = RREG32(MC_PMG_CMD_MRS1);
table->mc_reg_address[j].s1 = MC_PMG_CMD_MRS1 >> 2;
table->mc_reg_address[j].s0 = MC_SEQ_PMG_CMD_MRS1_LP >> 2;
@@ -2753,8 +2753,6 @@ static int ni_set_mc_special_registers(struct radeon_device *rdev,
(temp_reg & 0xffff0000) |
(table->mc_reg_table_entry[k].mc_data[i] & 0x0000ffff);
j++;
- if (j > SMC_NISLANDS_MC_REGISTER_ARRAY_SIZE)
- return -EINVAL;
break;
default:
break;
--
2.38.1