Commit 07773e5a authored Jun 06, 2024 by Wayne Lin Committed by Wenyu Huang Jun 06, 2024

drm/amd/display: Avoid NULL dereference of timing generator

stable inclusion
from stable-v5.10.202
commit 79b6a90f4f2433312154cd68452b0ba501fa74db
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9R4M5
CVE: CVE-2023-52753

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=79b6a90f4f2433312154cd68452b0ba501fa74db



--------------------------------

[ Upstream commit b1904ed480cee3f9f4036ea0e36d139cb5fee2d6 ]

[Why & How]
Check whether assigned timing generator is NULL or not before
accessing its funcs to prevent NULL dereference.

Reviewed-by: Jun Lei <jun.lei@amd.com>
Acked-by: Hersen Wu <hersenxs.wu@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Wenyu Huang <huangwenyu5@huawei.com>

parent eb0a4dfd

drivers/gpu/drm/amd/display/dc/core/dc_stream.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -534,7 +534,7 @@ uint32_t dc_stream_get_vblank_counter(const struct dc_stream_state *stream)
		for (i = 0; i < MAX_PIPES; i++) {
		struct timing_generator *tg = res_ctx->pipe_ctx[i].stream_res.tg;

		if (res_ctx->pipe_ctx[i].stream != stream)
		if (res_ctx->pipe_ctx[i].stream != stream \|\| !tg)
		continue;

		return tg->funcs->get_frame_count(tg);
		@@ -593,7 +593,7 @@ bool dc_stream_get_scanoutpos(const struct dc_stream_state *stream,
		for (i = 0; i < MAX_PIPES; i++) {
		struct timing_generator *tg = res_ctx->pipe_ctx[i].stream_res.tg;

		if (res_ctx->pipe_ctx[i].stream != stream)
		if (res_ctx->pipe_ctx[i].stream != stream \|\| !tg)
		continue;

		tg->funcs->get_scanoutpos(tg,