From 5b14cf37b9f01de0b28c6f8960019d4c7883ce42 Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Wed, 8 Nov 2023 13:31:57 -0600 Subject: [PATCH] drm/amd/display: fix a NULL pointer dereference in amdgpu_dm_i2c_xfer() commit b71f4ade1b8900d30c661d6c27f87c35214c398c upstream. When ddc_service_construct() is called, it explicitly checks both the link type and whether there is something on the link which will dictate whether the pin is marked as hw_supported. If the pin isn't set or the link is not set (such as from unloading/reloading amdgpu in an IGT test) then fail the amdgpu_dm_i2c_xfer() call. Cc: stable@vger.kernel.org Fixes: 22676bc500c2 ("drm/amd/display: Fix dmub soft hang for PSR 1") Link: https://github.com/fwupd/fwupd/issues/6327 Signed-off-by: Mario Limonciello Reviewed-by: Harry Wentland Signed-off-by: Alex Deucher Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 +++ 1 file changed, 3 insertions(+) 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 573e27399c79..b598ee84227e 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -7394,6 +7394,9 @@ static int amdgpu_dm_i2c_xfer(struct i2c_adapter *i2c_adap, int i; int result = -EIO; + if (!ddc_service->ddc_pin || !ddc_service->ddc_pin->hw_info.hw_supported) + return result; + cmd.payloads = kcalloc(num, sizeof(struct i2c_payload), GFP_KERNEL); if (!cmd.payloads)