| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 33/52] drm/amd/display: Guard against NULL pointer deref when get_i2c_info fails | Date | Fri, 5 Mar 2021 13:22:04 +0100 |
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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 fa0e6c8e2447..e3bedf4cc9c0 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -1124,6 +1124,11 @@ 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)); -- 2.30.1
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