Commit f6e28614 authored Nov 25, 2024 by Srinivasan Shanmugam Committed by dinglongwei Nov 25, 2024

drm/amd/display: Add NULL check for clk_mgr in dcn32_init_hw

stable inclusion
from stable-v6.10.14
commit f0454b3cb0584a6bf275aeb49be61a760fd546a2
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYR9K
CVE: CVE-2024-49915

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f0454b3cb0584a6bf275aeb49be61a760fd546a2



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

[ Upstream commit c395fd47d1565bd67671f45cca281b3acc2c31ef ]

This commit addresses a potential null pointer dereference issue in the
`dcn32_init_hw` function. The issue could occur when `dc->clk_mgr` is
null.

The fix adds a check to ensure `dc->clk_mgr` is not null before
accessing its functions. This prevents a potential null pointer
dereference.

Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn32/dcn32_hwseq.c:961 dcn32_init_hw() error: we previously assumed 'dc->clk_mgr' could be null (see line 782)

Cc: Tom Chung <chiahsuan.chung@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Roman Li <roman.li@amd.com>
Cc: Alex Hung <alex.hung@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Conflicts:
        drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c
[Context conflicts, the file of drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c has been moved to file
drivers/gpu/drm/amd/display/dc/hwss/dcn32/dcn32_hwseq.c int v6.10.14]
Signed-off-by: dinglongwei <dinglongwei1@huawei.com>

parent e2e6e833

drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -773,7 +773,7 @@ void dcn32_init_hw(struct dc *dc)
		int edp_num;
		uint32_t backlight = MAX_BACKLIGHT_LEVEL;

		if (dc->clk_mgr && dc->clk_mgr->funcs->init_clocks)
		if (dc->clk_mgr && dc->clk_mgr->funcs && dc->clk_mgr->funcs->init_clocks)
		dc->clk_mgr->funcs->init_clocks(dc->clk_mgr);

		// Initialize the dccg
		@@ -950,10 +950,11 @@ void dcn32_init_hw(struct dc *dc)
		if (!dcb->funcs->is_accelerated_mode(dcb) && dc->res_pool->hubbub->funcs->init_watermarks)
		dc->res_pool->hubbub->funcs->init_watermarks(dc->res_pool->hubbub);

		if (dc->clk_mgr->funcs->notify_wm_ranges)
		if (dc->clk_mgr && dc->clk_mgr->funcs && dc->clk_mgr->funcs->notify_wm_ranges)
		dc->clk_mgr->funcs->notify_wm_ranges(dc->clk_mgr);

		if (dc->clk_mgr->funcs->set_hard_max_memclk && !dc->clk_mgr->dc_mode_softmax_enabled)
		if (dc->clk_mgr && dc->clk_mgr->funcs && dc->clk_mgr->funcs->set_hard_max_memclk &&
		!dc->clk_mgr->dc_mode_softmax_enabled)
		dc->clk_mgr->funcs->set_hard_max_memclk(dc->clk_mgr);

		if (dc->res_pool->hubbub->funcs->force_pstate_change_control)