[PATCH AUTOSEL 5.4 19/40] drm/amd/display: Guard against NULL pointer deref when get_i2c_info fails
Sasha Levin
sashal at kernel.org
Wed Feb 24 12:53:19 UTC 2021
From: Nicholas Kazlauskas <nicholas.kazlauskas at 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 at amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
Reviewed-by: Eric Yang <eric.yang2 at amd.com>
Acked-by: Anson Jacob <anson.jacob at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Sasha Levin <sashal at 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 fa92b88bc5a13..40041c61a100e 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -1303,6 +1303,11 @@ static bool construct(
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));
--
2.27.0
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