Patch "drm/amd/display: Fix potential NULL pointer dereferences in 'dcn10_set_output_transfer_func()'" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/amd/display: Fix potential NULL pointer dereferences in 'dcn10_set_output_transfer_func()'

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-amd-display-fix-potential-null-pointer-dereferen.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 4030356b2a45449eba987c3917d130e0cd493f7b
Author: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
Date:   Thu Jan 25 21:16:04 2024 +0530

    drm/amd/display: Fix potential NULL pointer dereferences in 'dcn10_set_output_transfer_func()'
    
    [ Upstream commit 9ccfe80d022df7c595f1925afb31de2232900656 ]
    
    The 'stream' pointer is used in dcn10_set_output_transfer_func() before
    the check if 'stream' is NULL.
    
    Fixes the below:
    drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn10/dcn10_hwseq.c:1892 dcn10_set_output_transfer_func() warn: variable dereferenced before check 'stream' (see line 1875)
    
    Fixes: ddef02de0d71 ("drm/amd/display: add null checks before logging")
    Cc: Wyatt Wood <wyatt.wood@xxxxxxx>
    Cc: Anthony Koo <Anthony.Koo@xxxxxxx>
    Cc: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
    Cc: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>
    Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
    Reviewed-by: Anthony Koo <Anthony.Koo@xxxxxxx>
    Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
index db1d7be7fda38..e3f4d497d32d5 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
@@ -1832,6 +1832,9 @@ bool dcn10_set_output_transfer_func(struct dc *dc, struct pipe_ctx *pipe_ctx,
 {
 	struct dpp *dpp = pipe_ctx->plane_res.dpp;
 
+	if (!stream)
+		return false;
+
 	if (dpp == NULL)
 		return false;
 
@@ -1854,8 +1857,8 @@ bool dcn10_set_output_transfer_func(struct dc *dc, struct pipe_ctx *pipe_ctx,
 	} else
 		dpp->funcs->dpp_program_regamma_pwl(dpp, NULL, OPP_REGAMMA_BYPASS);
 
-	if (stream != NULL && stream->ctx != NULL &&
-			stream->out_transfer_func != NULL) {
+	if (stream->ctx &&
+	    stream->out_transfer_func) {
 		log_tf(stream->ctx,
 				stream->out_transfer_func,
 				dpp->regamma_params.hw_points_num);