From 486e263f8bd8472c045e7496f4a91e2da1c6470c Mon Sep 17 00:00:00 2001
From: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Date: Wed, 22 May 2024 20:54:50 +0530
Subject: [PATCH] drm/amdgpu/display: Fix null pointer dereference in
dc_stream_program_cursor_position
The fix involves adding a null check for 'stream' at the beginning of
the function. If 'stream' is NULL, the function immediately returns
false. This ensures that 'stream' is not NULL when we dereference it to
access 'ctx' in 'dc = stream->ctx->dc;' the function.
Fixes the below:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:398 dc_stream_program_cursor_position()
error: we previously assumed 'stream' could be null (see line 397)
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c
389 bool dc_stream_program_cursor_position(
390 struct dc_stream_state *stream,
391 const struct dc_cursor_position *position)
392 {
393 struct dc *dc;
394 bool reset_idle_optimizations = false;
395 const struct dc_cursor_position *old_position;
396
397 old_position = stream ? &stream->cursor_position : NULL;
^^^^^^^^
The patch adds a NULL check
--> 398 dc = stream->ctx->dc;
^^^^^^^^
The old code didn't check
399
400 if (dc_stream_set_cursor_position(stream, position)) {
401 dc_z10_restore(dc);
402
403 /* disable idle optimizations if enabling cursor */
404 if (dc->idle_optimizations_allowed &&
405 (!old_position->enable || dc->debug.exit_idle_opt_for_cursor_updates) &&
406 position->enable) {
407 dc_allow_idle_optimizations(dc, false);
Fixes: f63f86b5affc ("drm/amd/display: Separate setting and programming of cursor")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Tom Chung <chiahsuan.chung@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Roman Li <roman.li@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
---
drivers/gpu/drm/amd/display/dc/core/dc_stream.c | 5 ++++-
1 file changed, 4 insertions(+), 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 de48084eac250..55e1c19b97f1f 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
@@ -394,7 +394,10 @@ bool dc_stream_program_cursor_position(
bool reset_idle_optimizations = false;
const struct dc_cursor_position *old_position;
- old_position = stream ? &stream->cursor_position : NULL;
+ if (!stream)
+ return false;
+
+ old_position = &stream->cursor_position;
dc = stream->ctx->dc;
if (dc_stream_set_cursor_position(stream, position)) {
--
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