| From a8a358030563a7ef6ce0b6999601e1d3fd1a4b9e Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 18 Dec 2020 12:14:00 -0500 |
| Subject: drm/amd/display: Guard against NULL pointer deref when get_i2c_info |
| fails |
| |
| From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> |
| |
| [ Upstream commit 44a09e3d95bd2b7b0c224100f78f335859c4e193 ] |
| |
| [Why] |
| If the BIOS table is invalid or corrupt then get_i2c_info can fail |
| and we dereference a NULL pointer. |
| |
| [How] |
| Check that ddc_pin is not NULL before using it and log an error if it |
| is because this is unexpected. |
| |
| Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> |
| Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> |
| Reviewed-by: Eric Yang <eric.yang2@amd.com> |
| Acked-by: Anson Jacob <anson.jacob@amd.com> |
| Signed-off-by: Alex Deucher <alexander.deucher@amd.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/gpu/drm/amd/display/dc/core/dc_link.c | 5 +++++ |
| 1 file changed, 5 insertions(+) |
| |
| diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c |
| index f4a2088ab179..278ade3a90cc 100644 |
| --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c |
| +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c |
| @@ -1470,6 +1470,11 @@ static bool dc_link_construct(struct dc_link *link, |
| goto ddc_create_fail; |
| } |
| |
| + if (!link->ddc->ddc_pin) { |
| + DC_ERROR("Failed to get I2C info for connector!\n"); |
| + goto ddc_create_fail; |
| + } |
| + |
| link->ddc_hw_inst = |
| dal_ddc_get_line(dal_ddc_service_get_ddc_pin(link->ddc)); |
| |
| -- |
| 2.30.1 |
| |
