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From: Tuo Li <islituo@gmail.com>
To: harry.wentland@amd.com, sunpeng.li@amd.com,
	alexander.deucher@amd.com, christian.koenig@amd.com,
	Xinhui.Pan@amd.com, airlied@linux.ie, daniel@ffwll.ch,
	aric.cyr@amd.com, Jun.Lei@amd.com, qingqing.zhuo@amd.com,
	Rodrigo.Siqueira@amd.com, alvin.lee2@amd.com,
	vladimir.stempen@amd.com, isabel.zhang@amd.com, sung.lee@amd.com,
	paul.hsieh@amd.com, wyatt.wood@amd.com
Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	linux-kernel@vger.kernel.org, baijiaju1990@gmail.com,
	Tuo Li <islituo@gmail.com>, TOTE Robot <oslab@tsinghua.edu.cn>
Subject: [PATCH] drm/display: fix possible null-pointer dereference in dcn10_set_clock()
Date: Tue, 10 Aug 2021 02:20:04 -0700	[thread overview]
Message-ID: <20210810092004.291429-1-islituo@gmail.com> (raw)

The variable dc->clk_mgr is checked in:
  if (dc->clk_mgr && dc->clk_mgr->funcs->get_clock)

This indicates dc->clk_mgr can be NULL.
However, it is dereferenced in:
  if (!dc->clk_mgr->funcs->get_clock)

To fix this possible null-pointer dereference, check dc->clk_mgr before
dereferencing it.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Tuo Li <islituo@gmail.com>
---
 drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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 c545eddabdcc..3a7c7c7efa68 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
@@ -3635,7 +3635,7 @@ enum dc_status dcn10_set_clock(struct dc *dc,
 				dc->clk_mgr->funcs->get_clock(dc->clk_mgr,
 						context, clock_type, &clock_cfg);
 
-	if (!dc->clk_mgr->funcs->get_clock)
+	if (dc->clk_mgr && !dc->clk_mgr->funcs->get_clock)
 		return DC_FAIL_UNSUPPORTED_1;
 
 	if (clk_khz > clock_cfg.max_clock_khz)
-- 
2.25.1


             reply	other threads:[~2021-08-10  9:22 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-10  9:20 Tuo Li [this message]
2021-08-10 13:38 ` [PATCH] drm/display: fix possible null-pointer dereference in dcn10_set_clock() Chen, Guchun

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