From 99367bf45dc61dccf57207aede41c2142ea08f38 Mon Sep 17 00:00:00 2001 From: Xiaomeng Tong Date: Sun, 27 Mar 2022 13:20:28 +0800 Subject: [PATCH] gma500: fix an incorrect NULL check on list iterator commit bdef417d84536715145f6dc9cc3275c46f26295a upstream. The bug is here: return crtc; The list iterator value 'crtc' will *always* be set and non-NULL by list_for_each_entry(), so it is incorrect to assume that the iterator value will be NULL if the list is empty or no element is found. To fix the bug, return 'crtc' when found, otherwise return NULL. Cc: stable@vger.kernel.org fixes: 89c78134cc54d ("gma500: Add Poulsbo support") Signed-off-by: Xiaomeng Tong Signed-off-by: Patrik Jakobsson Link: https://patchwork.freedesktop.org/patch/msgid/20220327052028.2013-1-xiam0nd.tong@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/gma500/psb_intel_display.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/gma500/psb_intel_display.c b/drivers/gpu/drm/gma500/psb_intel_display.c index 3596064293167..6a578078e02f2 100644 --- a/drivers/gpu/drm/gma500/psb_intel_display.c +++ b/drivers/gpu/drm/gma500/psb_intel_display.c @@ -536,14 +536,15 @@ void psb_intel_crtc_init(struct drm_device *dev, int pipe, struct drm_crtc *psb_intel_get_crtc_from_pipe(struct drm_device *dev, int pipe) { - struct drm_crtc *crtc = NULL; + struct drm_crtc *crtc; list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) { struct gma_crtc *gma_crtc = to_gma_crtc(crtc); + if (gma_crtc->pipe == pipe) - break; + return crtc; } - return crtc; + return NULL; } int gma_connector_clones(struct drm_device *dev, int type_mask) -- 2.30.2