From 21ad38acbc18018c098c338eec3dd8184cc1ad46 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 46f506393bb40c4e2cfbde8dba36f642a180b254 ] 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: d6db65a0436f ("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 769f666335ac4..672d2239293e0 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; -- 2.39.5