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: 6016cd9dba0f ("drm/amd/display: add helper for enabling mst stream features") Cc: stable@vger.kernel.org Signed-off-by: Yizhuo Zhai yzhai003@ucr.edu --- drivers/gpu/drm/amd/display/dc/core/dc_link.c | 2 ++ 1 file changed, 2 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 c8457babfdea..fd5a0e7eb029 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -1844,6 +1844,8 @@ 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));