[PATCH 4.14 038/189] drm/msm: dont deref error pointer in the msm_fbdev_create error path

Greg Kroah-Hartman
2018-06-18T08:30:41Z

From: Emil Velikov <emil.velikov@collabora.com>

[ Upstream commit 789d4c300e10eb2096ee83c3497118e67ccc951e ]

Currently the error pointer returned by msm_alloc_stolen_fb gets passed
to drm_framebuffer_remove. The latter handles only NULL pointers, thus
a nasty crash will occur.

Drop the unnecessary fail label and the associated checks - both err and
fb will be set at this stage.

Cc: Rob Clark <robdclark@gmail.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: freedreno@lists.freedesktop.org
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/msm/msm_fbdev.c | 11 ++---------
1 file changed, 2 insertions(+), 9 deletions(-)

--- a/drivers/gpu/drm/msm/msm_fbdev.c
+++ b/drivers/gpu/drm/msm/msm_fbdev.c
@@ -92,8 +92,7 @@ static int msm_fbdev_create(struct drm_f

if (IS_ERR(fb)) {
dev_err(dev->dev, "failed to allocate fb\n");
- ret = PTR_ERR(fb);
- goto fail;
+ return PTR_ERR(fb);
}

bo = msm_framebuffer_bo(fb, 0);
@@ -151,13 +150,7 @@ static int msm_fbdev_create(struct drm_f

fail_unlock:
mutex_unlock(&dev->struct_mutex);
-fail:
-
- if (ret) {
- if (fb)
- drm_framebuffer_remove(fb);
- }
-
+ drm_framebuffer_remove(fb);
return ret;
}