Commit 0726ed30 authored by Yizhuo Zhai's avatar Yizhuo Zhai Committed by Alex Deucher
Browse files

drm/amd/display: Fix the uninitialized variable in enable_stream_features() 



In function enable_stream_features(), the variable "old_downspread.raw"
could be uninitialized if core_link_read_dpcd() fails, however, it is
used in the later if statement, and further, core_link_write_dpcd()
may write random value, which is potentially unsafe.

Fixes: 6016cd9d ("drm/amd/display: add helper for enabling mst stream features")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarYizhuo Zhai <yzhai003@ucr.edu>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 937ed9c8

drivers/gpu/drm/amd/display/dc/core/dc_link.c

+2 −0
Original line number Diff line number Diff line
@@ -1818,6 +1818,8 @@ static void enable_stream_features(struct pipe_ctx *pipe_ctx) 
		union down_spread_ctrl old_downspread;

		union down_spread_ctrl new_downspread;



		memset(&old_downspread, 0, sizeof(old_downspread));



		core_link_read_dpcd(link, DP_DOWNSPREAD_CTRL,

				&old_downspread.raw, sizeof(old_downspread));