drm/crtc: fix uninitialized variable use

[ Upstream commit 6e455f5dcdd15fa28edf0ffb5b44d3508512dccf ]

Commit 3823119b9c2b ("drm/crtc: Fix uninit-value bug in
drm_mode_setcrtc") was supposed to fix use of an uninitialized variable,
but introduced another.

num_connectors is only initialized if crtc_req->count_connectors > 0,
but it's used regardless. Fix it.

Fixes: 3823119b9c2b ("drm/crtc: Fix uninit-value bug in drm_mode_setcrtc")
Cc: syzbot+4fad2e57beb6397ab2fc@syzkaller.appspotmail.com
Cc: Ziqi Zhao <astrajoan@yahoo.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231208131238.2924571-1-jani.nikula@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index d718c17..cb90e70 100644 (file)
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -715,7 +715,7 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
        struct drm_mode_set set;
        uint32_t __user *set_connectors_ptr;
        struct drm_modeset_acquire_ctx ctx;
-       int ret, i, num_connectors;
+       int ret, i, num_connectors = 0;
 
        if (!drm_core_check_feature(dev, DRIVER_MODESET))
                return -EOPNOTSUPP;
@@ -850,7 +850,6 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
                        goto out;
                }
 
-               num_connectors = 0;
                for (i = 0; i < crtc_req->count_connectors; i++) {
                        connector_set[i] = NULL;
                        set_connectors_ptr = (uint32_t __user *)(unsigned long)crtc_req->set_connectors_ptr;