Hi All:
I just found a bug in the cramfs using the static analysis tool, but
not sure if this could happen in reality, could you please advise me
here? Thanks for your attention : ) And please ignore the last one
with HTML format if you did not filter it out.
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. But this function does not return the error code to the up
caller and I got stuck in drafting the patch, could you please advise
me here?
The related code:
static void enable_stream_features(struct pipe_ctx *pipe_ctx)
{
union down_spread_ctrl old_downspread;
core_link_read_dpcd(link, DP_DOWNSPREAD_CTRL,
&old_downspread.raw, sizeof(old_downspread);
//old_downspread.raw used here
if (new_downspread.raw != old_downspread.raw) {
core_link_write_dpcd(link, DP_DOWNSPREAD_CTRL,
&new_downspread.raw, sizeof(new_downspread));
}
}
enum dc_status core_link_read_dpcd(
struct dc_link *link,
uint32_t address,
uint8_t *data,
uint32_t size)
{
//data could be uninitialized if the helpers fails and log
some error info
if (!dm_helpers_dp_read_dpcd(link->ctx,
link,address, data, size))
return DC_ERROR_UNEXPECTED;
return DC_OK;
}
The same issue in function wait_for_training_aux_rd_interval() in
drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
--
Kind Regards,
Yizhuo Zhai
Computer Science, Graduate Student
University of California, Riverside
