From: Hersen Wu <hersenxs.wu@amd.com>
Date: Wed, 24 Apr 2024 20:15:15 +0000 (-0400)
Subject: drm/amd/display: Stop amdgpu_dm initialize when link nums greater than max_links
X-Git-Tag: v5.15.181~157
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e3cd0d8362de47f613bfdf315b3f3a9ab71e66bf;p=thirdparty%2Fkernel%2Fstable.git

drm/amd/display: Stop amdgpu_dm initialize when link nums greater than max_links

commit cf8b16857db702ceb8d52f9219a4613363e2b1cf upstream.

[Why]
Coverity report OVERRUN warning. There are
only max_links elements within dc->links. link
count could up to AMDGPU_DM_MAX_DISPLAY_INDEX 31.

[How]
Make sure link count less than max_links.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Minor conflict resolved due to code context change. And the macro MAX_LINKS
 is introduced by Commit 60df5628144b ("drm/amd/display: handle invalid
 connector indices") after 6.10. So here we still use the original array
 length MAX_PIPES * 2]
Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com>
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index a33ca712a89c5..b1f4d8a84e1ba 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -4321,17 +4321,17 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev)
 	}
 #endif
 
+	if (link_cnt > (MAX_PIPES * 2)) {
+		DRM_ERROR(
+			"KMS: Cannot support more than %d display indexes\n",
+				MAX_PIPES * 2);
+		goto fail;
+	}
+
 	/* loops over all connectors on the board */
 	for (i = 0; i < link_cnt; i++) {
 		struct dc_link *link = NULL;
 
-		if (i > AMDGPU_DM_MAX_DISPLAY_INDEX) {
-			DRM_ERROR(
-				"KMS: Cannot support more than %d display indexes\n",
-					AMDGPU_DM_MAX_DISPLAY_INDEX);
-			continue;
-		}
-
 		aconnector = kzalloc(sizeof(*aconnector), GFP_KERNEL);
 		if (!aconnector)
 			goto fail;