Re: [PATCH] drm/amd/display: fix array-bounds error in dc_stream_remove_writeback()
From: Hamza Mahfooz
Date: Thu Sep 29 2022 - 11:43:02 EST
On 2022-09-29 11:36, Felix Kuehling wrote:
I'm still seeing a warning even with this fix:
/home/fkuehlin/compute/kernel/drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c: In function ?dc_stream_remove_writeback?:
/home/fkuehlin/compute/kernel/drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:527:55: warning: array subscript 1 is above array bounds of ?struct dc_writeback_info[1]? [-Warray-bounds]
527 | stream->writeback_info[j] = stream->writeback_info[i];
| ~~~~~~~~~~~~~~~~~~~~~~^~~
What version of GCC are you using? I don't see it on GCC 12.2 with this
patch applied.
Regards,
Felix
Am 2022-09-27 um 16:35 schrieb Pillai, Aurabindo:
[AMD Official Use Only - General]
[AMD Official Use Only - General]
Reviewed-by: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>
--
Regards,
Jay
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*Subject:* [PATCH] drm/amd/display: fix array-bounds error in
dc_stream_remove_writeback()
Address the following error:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c: In function
‘dc_stream_remove_writeback’:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:527:55:
error: array subscript [0, 0] is outside array bounds of ‘struct
dc_writeback_info[1]’ [-Werror=array-bounds]
527 | stream->writeback_info[j] = stream->writeback_info[i];
| ~~~~~~~~~~~~~~~~~~~~~~^~~
In file included from
./drivers/gpu/drm/amd/amdgpu/../display/dc/dc.h:1269,
from
./drivers/gpu/drm/amd/amdgpu/../display/dc/inc/core_types.h:29,
from
./drivers/gpu/drm/amd/amdgpu/../display/dc/basics/dc_common.h:29,
from
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:27:
./drivers/gpu/drm/amd/amdgpu/../display/dc/dc_stream.h:241:34: note:
while referencing ‘writeback_info’
241 | struct dc_writeback_info writeback_info[MAX_DWB_PIPES];
|
Currently, we aren't checking to see if j remains within
writeback_info[]'s bounds. So, add a check to make sure that we aren't
overflowing the buffer.
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@xxxxxxx>
---
drivers/gpu/drm/amd/display/dc/core/dc_stream.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
index 3ca1592ce7ac..ae13887756bf 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
@@ -520,7 +520,7 @@ bool dc_stream_remove_writeback(struct dc *dc,
}
/* remove writeback info for disabled writeback pipes from
stream */
- for (i = 0, j = 0; i < stream->num_wb_info; i++) {
+ for (i = 0, j = 0; i < stream->num_wb_info && j <
MAX_DWB_PIPES; i++) {
if (stream->writeback_info[i].wb_enabled) {
if (i != j)
/* trim the array */
--
2.37.2
--
Hamza