From: Jocelyn Falempe jfalempe@redhat.com
commit c2a88e8bdf5f6239948d75283d0ae7e0c7945b03 upstream.
dmt_mode is allocated and never freed in this function. It was found with the ast driver, but most drivers using generic fbdev setup are probably affected.
This fixes the following kmemleak report: backtrace: [<00000000b391296d>] drm_mode_duplicate+0x45/0x220 [drm] [<00000000e45bb5b3>] drm_client_target_cloned.constprop.0+0x27b/0x480 [drm] [<00000000ed2d3a37>] drm_client_modeset_probe+0x6bd/0xf50 [drm] [<0000000010e5cc9d>] __drm_fb_helper_initial_config_and_unlock+0xb4/0x2c0 [drm_kms_helper] [<00000000909f82ca>] drm_fbdev_client_hotplug+0x2bc/0x4d0 [drm_kms_helper] [<00000000063a69aa>] drm_client_register+0x169/0x240 [drm] [<00000000a8c61525>] ast_pci_probe+0x142/0x190 [ast] [<00000000987f19bb>] local_pci_probe+0xdc/0x180 [<000000004fca231b>] work_for_cpu_fn+0x4e/0xa0 [<0000000000b85301>] process_one_work+0x8b7/0x1540 [<000000003375b17c>] worker_thread+0x70a/0xed0 [<00000000b0d43cd9>] kthread+0x29f/0x340 [<000000008d770833>] ret_from_fork+0x1f/0x30 unreferenced object 0xff11000333089a00 (size 128):
cc: stable@vger.kernel.org Fixes: 1d42bbc8f7f9 ("drm/fbdev: fix cloning on fbcon") Reported-by: Zhang Yi yizhan@redhat.com Signed-off-by: Jocelyn Falempe jfalempe@redhat.com Reviewed-by: Javier Martinez Canillas javierm@redhat.com Reviewed-by: Thomas Zimmermann tzimmermann@suse.de Link: https://patchwork.freedesktop.org/patch/msgid/20230711092203.68157-2-jfalemp... Signed-off-by: Jocelyn Falempe jfalempe@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/drm_fb_helper.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -2233,6 +2233,9 @@ static bool drm_target_cloned(struct drm can_clone = true; dmt_mode = drm_mode_find_dmt(fb_helper->dev, 1024, 768, 60, false);
+ if (!dmt_mode) + goto fail; + drm_fb_helper_for_each_connector(fb_helper, i) { if (!enabled[i]) continue; @@ -2249,11 +2252,13 @@ static bool drm_target_cloned(struct drm if (!modes[i]) can_clone = false; } + kfree(dmt_mode);
if (can_clone) { DRM_DEBUG_KMS("can clone using 1024x768\n"); return true; } +fail: DRM_INFO("kms: can't enable cloning when we probably wanted to.\n"); return false; }