drm: Prevent NULL deref in drm_name_info() (e4245ea8) · Commits · 戴 / test

If a driver does not have a parent, or never sets the unique name for itself, then we may proceed to chase a NULL dereference through debugfs/.../name. Testcase: igt/vgem_basic/debugfs Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by:

Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1466448813-23340-1-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/drm_info.c

+10 −11

Original line number	Diff line number	Diff line
		@@ -51,17 +51,16 @@ int drm_name_info(struct seq_file m, void data)
		struct drm_minor *minor = node->minor;
		struct drm_device *dev = minor->dev;
		struct drm_master *master = minor->master;
		if (!master)
		return 0;

		if (master->unique) {
		seq_printf(m, "%s %s %s\n",
		dev->driver->name,
		dev_name(dev->dev), master->unique);
		} else {
		seq_printf(m, "%s %s\n",
		dev->driver->name, dev_name(dev->dev));
		}
		seq_printf(m, "%s", dev->driver->name);
		if (dev->dev)
		seq_printf(m, " dev=%s", dev_name(dev->dev));
		if (master && master->unique)
		seq_printf(m, " master=%s", master->unique);
		if (dev->unique)
		seq_printf(m, " unique=%s", dev->unique);
		seq_printf(m, "\n");

		return 0;
		}

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