Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Rob Clark <robdclark@gmail.com>
To:     dri-devel@lists.freedesktop.org
Cc:     Rob Clark <robdclark@chromium.org>,
        Emil Velikov <emil.velikov@collabora.com>,
        Rob Clark <robdclark@gmail.com>, Sean Paul <sean@poorly.run>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        "Kristian H. Kristensen" <hoegsberg@google.com>,
        linux-arm-msm@vger.kernel.org (open list:DRM DRIVER FOR MSM ADRENO GPU),
        freedreno@lists.freedesktop.org (open list:DRM DRIVER FOR MSM ADRENO
        GPU), linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] drm/msm: Fix legacy relocs path
Date:   Thu,  4 Feb 2021 14:56:49 -0800
Message-Id: <20210204225650.1284384-1-robdclark@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Rob Clark <robdclark@chromium.org>

In moving code around, we ended up using the same pointer to
copy_from_user() the relocs tables as we used for the cmd table
entry, which is clearly not right.  This went unnoticed because
modern mesa on non-ancent kernels does not actually use relocs.
But this broke ancient mesa on modern kernels.

Reported-by: Emil Velikov <emil.velikov@collabora.com>
Fixes: 20224d715a88 ("drm/msm/submit: Move copy_from_user ahead of locking bos")
Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 drivers/gpu/drm/msm/msm_gem_submit.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index d04c349d8112..5480852bdeda 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -198,6 +198,8 @@ static int submit_lookup_cmds(struct msm_gem_submit *submit,
 		submit->cmd[i].idx  = submit_cmd.submit_idx;
 		submit->cmd[i].nr_relocs = submit_cmd.nr_relocs;
 
+		userptr = u64_to_user_ptr(submit_cmd.relocs);
+
 		sz = array_size(submit_cmd.nr_relocs,
 				sizeof(struct drm_msm_gem_submit_reloc));
 		/* check for overflow: */
-- 
2.29.2