[PATCH AUTOSEL 4.19 14/26] drm/amd/display: Guard against NULL pointer deref when get_i2c_info fails
From: Sasha Levin <sashal@kernel.org>
Date: 2021-02-24 14:07:25
Also in:
amd-gfx, dri-devel, lkml
Subsystem:
amd display core, drm drivers, radeon and amdgpu drm drivers, the rest · Maintainers:
Harry Wentland, Leo Li, David Airlie, Simona Vetter, Alex Deucher, Christian König, Linus Torvalds
From: Nicholas Kazlauskas <redacted> [ 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 <redacted> Signed-off-by: Nicholas Kazlauskas <redacted> Reviewed-by: Eric Yang <redacted> Acked-by: Anson Jacob <redacted> 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 fa0e6c8e2447c..e3bedf4cc9c03 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));
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2.27.0