From: =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= Date: Mon, 14 Aug 2017 23:53:45 +0200 Subject: drm/tegra: Fix NULL deref in debugfs/iova MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Git-commit: 68d890a3cca5a96a5443972922c84df89f6301e6 Patch-mainline: v4.14-rc1 References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166 When IOMMU is off, ->mm_lock is not initialized and ->mm is NULL. Signed-off-by: Michał Mirosław Signed-off-by: Thierry Reding Acked-by: Petr Tesarik --- drivers/gpu/drm/tegra/drm.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/tegra/drm.c +++ b/drivers/gpu/drm/tegra/drm.c @@ -1035,9 +1035,11 @@ static int tegra_debugfs_iova(struct seq struct tegra_drm *tegra = drm->dev_private; struct drm_printer p = drm_seq_file_printer(s); - mutex_lock(&tegra->mm_lock); - drm_mm_print(&tegra->mm, &p); - mutex_unlock(&tegra->mm_lock); + if (tegra->domain) { + mutex_lock(&tegra->mm_lock); + drm_mm_print(&tegra->mm, &p); + mutex_unlock(&tegra->mm_lock); + } return 0; }