| Message ID | 20211218042226.2608212-1-yzhai003@ucr.edu |
|---|---|
| State | Accepted |
| Commit | 0726ed3065eeb910f9cea0c933bc021a848e00b3 |
| Headers | show |
| Series | drm/amd/display: Fix the uninitialized variable in enable_stream_features() | expand |
Applied. Thanks! Alex On Fri, Dec 17, 2021 at 11:22 PM Yizhuo Zhai <yzhai003@ucr.edu> wrote: > > 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)); > > -- > 2.25.1 >
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));
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(+)