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From: Imre Deak <imre.deak@intel.com>
To: dri-devel@lists.freedesktop.org
Cc: Dave Airlie <airlied@redhat.com>, Daniel Vetter <daniel.vetter@ffwll.ch>
Subject: [PATCH v2 2/3] drm/mst: Avoid dereferencing a NULL mstb in drm_dp_mst_handle_up_req()
Date: Wed, 19 Jul 2017 14:43:29 +0300	[thread overview]
Message-ID: <20170719114330.26540-3-imre.deak@intel.com> (raw)
In-Reply-To: <20170719114330.26540-1-imre.deak@intel.com>

In case of an unknown broadcast message is sent mstb will remain unset,
so check for this.

Cc: Dave Airlie <airlied@redhat.com>
Cc: Lyude <lyude@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Lyude <lyude@redhat.com>
---
 drivers/gpu/drm/drm_dp_mst_topology.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index c6ae3e68918f..78e9a7d58794 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2328,7 +2328,9 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
 			DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
 		}
 
-		drm_dp_put_mst_branch_device(mstb);
+		if (mstb)
+			drm_dp_put_mst_branch_device(mstb);
+
 		memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
 	}
 	return ret;
-- 
2.13.2

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  parent reply	other threads:[~2017-07-19 11:43 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-19 11:43 [PATCH v2 0/3] drm/mst: Fix sideband msg reception error path Imre Deak
2017-07-19 11:43 ` [PATCH v2 1/3] drm/mst: Fix error handling during MST sideband message reception Imre Deak
2017-07-19 11:43 ` Imre Deak [this message]
2017-07-19 11:43 ` [PATCH v2 3/3] drm/mst: Avoid processing partially received up/down message transactions Imre Deak
2017-07-19 13:46   ` [PATCH v3 " Imre Deak
2017-07-19 18:16     ` Lyude Paul
2017-07-19 18:16 ` [PATCH v2 0/3] drm/mst: Fix sideband msg reception error path Lyude Paul
2017-07-20  8:21   ` Daniel Vetter
2017-07-20  8:47   ` Imre Deak

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