From: Harry Wentland <[email protected]> [Why & How] The VBIOS integrated info tables (v1_11 and v2_1) contain HdmiRegNum and Hdmi6GRegNum fields that are used as loop bounds when copying retimer I2C register settings into fixed-size arrays (dp*_ext_hdmi_reg_settings[9] and dp*_ext_hdmi_6g_reg_settings[3]). These u8 fields are not validated before use, so a malformed VBIOS can specify values up to 255, causing an out-of-bounds heap write during driver probe.
Clamp each register count to the destination array size using min_t() before the copy loops, in both get_integrated_info_v11() and get_integrated_info_v2_1(). Cc: [email protected] Assisted-by: GitHub Copilot:claude-opus-4.6 Reviewed-by: Alex Hung <[email protected]> Signed-off-by: Harry Wentland <[email protected]> Signed-off-by: Ray Wu <[email protected]> --- .../drm/amd/display/dc/bios/bios_parser2.c | 48 ++++++++++++------- 1 file changed, 32 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c b/drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c index d19ae67ebfac..6cbdf356b1cd 100644 --- a/drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c +++ b/drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c @@ -2600,14 +2600,16 @@ static enum bp_result get_integrated_info_v11( info_v11->extdispconninfo.checksum; info->dp0_ext_hdmi_slv_addr = info_v11->dp0_retimer_set.HdmiSlvAddr; - info->dp0_ext_hdmi_reg_num = info_v11->dp0_retimer_set.HdmiRegNum; + info->dp0_ext_hdmi_reg_num = min_t(u8, info_v11->dp0_retimer_set.HdmiRegNum, + ARRAY_SIZE(info->dp0_ext_hdmi_reg_settings)); for (i = 0; i < info->dp0_ext_hdmi_reg_num; i++) { info->dp0_ext_hdmi_reg_settings[i].i2c_reg_index = info_v11->dp0_retimer_set.HdmiRegSetting[i].ucI2cRegIndex; info->dp0_ext_hdmi_reg_settings[i].i2c_reg_val = info_v11->dp0_retimer_set.HdmiRegSetting[i].ucI2cRegVal; } - info->dp0_ext_hdmi_6g_reg_num = info_v11->dp0_retimer_set.Hdmi6GRegNum; + info->dp0_ext_hdmi_6g_reg_num = min_t(u8, info_v11->dp0_retimer_set.Hdmi6GRegNum, + ARRAY_SIZE(info->dp0_ext_hdmi_6g_reg_settings)); for (i = 0; i < info->dp0_ext_hdmi_6g_reg_num; i++) { info->dp0_ext_hdmi_6g_reg_settings[i].i2c_reg_index = info_v11->dp0_retimer_set.Hdmi6GhzRegSetting[i].ucI2cRegIndex; @@ -2616,14 +2618,16 @@ static enum bp_result get_integrated_info_v11( } info->dp1_ext_hdmi_slv_addr = info_v11->dp1_retimer_set.HdmiSlvAddr; - info->dp1_ext_hdmi_reg_num = info_v11->dp1_retimer_set.HdmiRegNum; + info->dp1_ext_hdmi_reg_num = min_t(u8, info_v11->dp1_retimer_set.HdmiRegNum, + ARRAY_SIZE(info->dp1_ext_hdmi_reg_settings)); for (i = 0; i < info->dp1_ext_hdmi_reg_num; i++) { info->dp1_ext_hdmi_reg_settings[i].i2c_reg_index = info_v11->dp1_retimer_set.HdmiRegSetting[i].ucI2cRegIndex; info->dp1_ext_hdmi_reg_settings[i].i2c_reg_val = info_v11->dp1_retimer_set.HdmiRegSetting[i].ucI2cRegVal; } - info->dp1_ext_hdmi_6g_reg_num = info_v11->dp1_retimer_set.Hdmi6GRegNum; + info->dp1_ext_hdmi_6g_reg_num = min_t(u8, info_v11->dp1_retimer_set.Hdmi6GRegNum, + ARRAY_SIZE(info->dp1_ext_hdmi_6g_reg_settings)); for (i = 0; i < info->dp1_ext_hdmi_6g_reg_num; i++) { info->dp1_ext_hdmi_6g_reg_settings[i].i2c_reg_index = info_v11->dp1_retimer_set.Hdmi6GhzRegSetting[i].ucI2cRegIndex; @@ -2632,14 +2636,16 @@ static enum bp_result get_integrated_info_v11( } info->dp2_ext_hdmi_slv_addr = info_v11->dp2_retimer_set.HdmiSlvAddr; - info->dp2_ext_hdmi_reg_num = info_v11->dp2_retimer_set.HdmiRegNum; + info->dp2_ext_hdmi_reg_num = min_t(u8, info_v11->dp2_retimer_set.HdmiRegNum, + ARRAY_SIZE(info->dp2_ext_hdmi_reg_settings)); for (i = 0; i < info->dp2_ext_hdmi_reg_num; i++) { info->dp2_ext_hdmi_reg_settings[i].i2c_reg_index = info_v11->dp2_retimer_set.HdmiRegSetting[i].ucI2cRegIndex; info->dp2_ext_hdmi_reg_settings[i].i2c_reg_val = info_v11->dp2_retimer_set.HdmiRegSetting[i].ucI2cRegVal; } - info->dp2_ext_hdmi_6g_reg_num = info_v11->dp2_retimer_set.Hdmi6GRegNum; + info->dp2_ext_hdmi_6g_reg_num = min_t(u8, info_v11->dp2_retimer_set.Hdmi6GRegNum, + ARRAY_SIZE(info->dp2_ext_hdmi_6g_reg_settings)); for (i = 0; i < info->dp2_ext_hdmi_6g_reg_num; i++) { info->dp2_ext_hdmi_6g_reg_settings[i].i2c_reg_index = info_v11->dp2_retimer_set.Hdmi6GhzRegSetting[i].ucI2cRegIndex; @@ -2648,14 +2654,16 @@ static enum bp_result get_integrated_info_v11( } info->dp3_ext_hdmi_slv_addr = info_v11->dp3_retimer_set.HdmiSlvAddr; - info->dp3_ext_hdmi_reg_num = info_v11->dp3_retimer_set.HdmiRegNum; + info->dp3_ext_hdmi_reg_num = min_t(u8, info_v11->dp3_retimer_set.HdmiRegNum, + ARRAY_SIZE(info->dp3_ext_hdmi_reg_settings)); for (i = 0; i < info->dp3_ext_hdmi_reg_num; i++) { info->dp3_ext_hdmi_reg_settings[i].i2c_reg_index = info_v11->dp3_retimer_set.HdmiRegSetting[i].ucI2cRegIndex; info->dp3_ext_hdmi_reg_settings[i].i2c_reg_val = info_v11->dp3_retimer_set.HdmiRegSetting[i].ucI2cRegVal; } - info->dp3_ext_hdmi_6g_reg_num = info_v11->dp3_retimer_set.Hdmi6GRegNum; + info->dp3_ext_hdmi_6g_reg_num = min_t(u8, info_v11->dp3_retimer_set.Hdmi6GRegNum, + ARRAY_SIZE(info->dp3_ext_hdmi_6g_reg_settings)); for (i = 0; i < info->dp3_ext_hdmi_6g_reg_num; i++) { info->dp3_ext_hdmi_6g_reg_settings[i].i2c_reg_index = info_v11->dp3_retimer_set.Hdmi6GhzRegSetting[i].ucI2cRegIndex; @@ -2796,14 +2804,16 @@ static enum bp_result get_integrated_info_v2_1( info->ext_disp_conn_info.checksum = info_v2_1->extdispconninfo.checksum; info->dp0_ext_hdmi_slv_addr = info_v2_1->dp0_retimer_set.HdmiSlvAddr; - info->dp0_ext_hdmi_reg_num = info_v2_1->dp0_retimer_set.HdmiRegNum; + info->dp0_ext_hdmi_reg_num = min_t(u8, info_v2_1->dp0_retimer_set.HdmiRegNum, + ARRAY_SIZE(info->dp0_ext_hdmi_reg_settings)); for (i = 0; i < info->dp0_ext_hdmi_reg_num; i++) { info->dp0_ext_hdmi_reg_settings[i].i2c_reg_index = info_v2_1->dp0_retimer_set.HdmiRegSetting[i].ucI2cRegIndex; info->dp0_ext_hdmi_reg_settings[i].i2c_reg_val = info_v2_1->dp0_retimer_set.HdmiRegSetting[i].ucI2cRegVal; } - info->dp0_ext_hdmi_6g_reg_num = info_v2_1->dp0_retimer_set.Hdmi6GRegNum; + info->dp0_ext_hdmi_6g_reg_num = min_t(u8, info_v2_1->dp0_retimer_set.Hdmi6GRegNum, + ARRAY_SIZE(info->dp0_ext_hdmi_6g_reg_settings)); for (i = 0; i < info->dp0_ext_hdmi_6g_reg_num; i++) { info->dp0_ext_hdmi_6g_reg_settings[i].i2c_reg_index = info_v2_1->dp0_retimer_set.Hdmi6GhzRegSetting[i].ucI2cRegIndex; @@ -2811,14 +2821,16 @@ static enum bp_result get_integrated_info_v2_1( info_v2_1->dp0_retimer_set.Hdmi6GhzRegSetting[i].ucI2cRegVal; } info->dp1_ext_hdmi_slv_addr = info_v2_1->dp1_retimer_set.HdmiSlvAddr; - info->dp1_ext_hdmi_reg_num = info_v2_1->dp1_retimer_set.HdmiRegNum; + info->dp1_ext_hdmi_reg_num = min_t(u8, info_v2_1->dp1_retimer_set.HdmiRegNum, + ARRAY_SIZE(info->dp1_ext_hdmi_reg_settings)); for (i = 0; i < info->dp1_ext_hdmi_reg_num; i++) { info->dp1_ext_hdmi_reg_settings[i].i2c_reg_index = info_v2_1->dp1_retimer_set.HdmiRegSetting[i].ucI2cRegIndex; info->dp1_ext_hdmi_reg_settings[i].i2c_reg_val = info_v2_1->dp1_retimer_set.HdmiRegSetting[i].ucI2cRegVal; } - info->dp1_ext_hdmi_6g_reg_num = info_v2_1->dp1_retimer_set.Hdmi6GRegNum; + info->dp1_ext_hdmi_6g_reg_num = min_t(u8, info_v2_1->dp1_retimer_set.Hdmi6GRegNum, + ARRAY_SIZE(info->dp1_ext_hdmi_6g_reg_settings)); for (i = 0; i < info->dp1_ext_hdmi_6g_reg_num; i++) { info->dp1_ext_hdmi_6g_reg_settings[i].i2c_reg_index = info_v2_1->dp1_retimer_set.Hdmi6GhzRegSetting[i].ucI2cRegIndex; @@ -2826,14 +2838,16 @@ static enum bp_result get_integrated_info_v2_1( info_v2_1->dp1_retimer_set.Hdmi6GhzRegSetting[i].ucI2cRegVal; } info->dp2_ext_hdmi_slv_addr = info_v2_1->dp2_retimer_set.HdmiSlvAddr; - info->dp2_ext_hdmi_reg_num = info_v2_1->dp2_retimer_set.HdmiRegNum; + info->dp2_ext_hdmi_reg_num = min_t(u8, info_v2_1->dp2_retimer_set.HdmiRegNum, + ARRAY_SIZE(info->dp2_ext_hdmi_reg_settings)); for (i = 0; i < info->dp2_ext_hdmi_reg_num; i++) { info->dp2_ext_hdmi_reg_settings[i].i2c_reg_index = info_v2_1->dp2_retimer_set.HdmiRegSetting[i].ucI2cRegIndex; info->dp2_ext_hdmi_reg_settings[i].i2c_reg_val = info_v2_1->dp2_retimer_set.HdmiRegSetting[i].ucI2cRegVal; } - info->dp2_ext_hdmi_6g_reg_num = info_v2_1->dp2_retimer_set.Hdmi6GRegNum; + info->dp2_ext_hdmi_6g_reg_num = min_t(u8, info_v2_1->dp2_retimer_set.Hdmi6GRegNum, + ARRAY_SIZE(info->dp2_ext_hdmi_6g_reg_settings)); for (i = 0; i < info->dp2_ext_hdmi_6g_reg_num; i++) { info->dp2_ext_hdmi_6g_reg_settings[i].i2c_reg_index = info_v2_1->dp2_retimer_set.Hdmi6GhzRegSetting[i].ucI2cRegIndex; @@ -2841,14 +2855,16 @@ static enum bp_result get_integrated_info_v2_1( info_v2_1->dp2_retimer_set.Hdmi6GhzRegSetting[i].ucI2cRegVal; } info->dp3_ext_hdmi_slv_addr = info_v2_1->dp3_retimer_set.HdmiSlvAddr; - info->dp3_ext_hdmi_reg_num = info_v2_1->dp3_retimer_set.HdmiRegNum; + info->dp3_ext_hdmi_reg_num = min_t(u8, info_v2_1->dp3_retimer_set.HdmiRegNum, + ARRAY_SIZE(info->dp3_ext_hdmi_reg_settings)); for (i = 0; i < info->dp3_ext_hdmi_reg_num; i++) { info->dp3_ext_hdmi_reg_settings[i].i2c_reg_index = info_v2_1->dp3_retimer_set.HdmiRegSetting[i].ucI2cRegIndex; info->dp3_ext_hdmi_reg_settings[i].i2c_reg_val = info_v2_1->dp3_retimer_set.HdmiRegSetting[i].ucI2cRegVal; } - info->dp3_ext_hdmi_6g_reg_num = info_v2_1->dp3_retimer_set.Hdmi6GRegNum; + info->dp3_ext_hdmi_6g_reg_num = min_t(u8, info_v2_1->dp3_retimer_set.Hdmi6GRegNum, + ARRAY_SIZE(info->dp3_ext_hdmi_6g_reg_settings)); for (i = 0; i < info->dp3_ext_hdmi_6g_reg_num; i++) { info->dp3_ext_hdmi_6g_reg_settings[i].i2c_reg_index = info_v2_1->dp3_retimer_set.Hdmi6GhzRegSetting[i].ucI2cRegIndex; -- 2.43.0
