This is a note to let you know that I've just added the patch titled drm/radeon: fix potential buffer overflow in ni_set_mc_special_registers() to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-radeon-fix-potential-buffer-overflow-in-ni_set_m.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 756769ef5d66dffba7148aac7d2401d4f8e2ed03 Author: Alexey Kodanev <aleksei.kodanev@xxxxxxxxxxx> Date: Mon Jun 6 16:50:54 2022 +0300 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 <aleksei.kodanev@xxxxxxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/radeon/ni_dpm.c b/drivers/gpu/drm/radeon/ni_dpm.c index a32cf6dbd3ee..cae3738885c8 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;