From 1f341053852be76f82610ce47a505d930512f05c Mon Sep 17 00:00:00 2001 From: Alexey Kodanev Date: Mon, 6 Jun 2022 16:50:54 +0300 Subject: [PATCH] drm/radeon: fix potential buffer overflow in ni_set_mc_special_registers() [ Upstream commit 136f614931a2bb73616b292cf542da3a18daefd5 ] 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 Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- 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 f86ca163dcf3..a7273c01de34 100644 --- a/drivers/gpu/drm/radeon/ni_dpm.c +++ b/drivers/gpu/drm/radeon/ni_dpm.c @@ -2738,10 +2738,10 @@ 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; @@ -2750,8 +2750,6 @@ 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;