From a4b978249e8fa94956fce8b70a709f7797716f62 Mon Sep 17 00:00:00 2001 From: Jocelyn Falempe Date: Tue, 11 Jul 2023 11:20:43 +0200 Subject: [PATCH] drm/client: Fix memory leak in drm_client_target_cloned 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: Fixes: 1d42bbc8f7f9 ("drm/fbdev: fix cloning on fbcon") Reported-by: Zhang Yi Signed-off-by: Jocelyn Falempe Reviewed-by: Javier Martinez Canillas Reviewed-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20230711092203.68157-2-jfalempe@redhat.com Signed-off-by: Jocelyn Falempe Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_fb_helper.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index fbe9156c9e7c..ee6801fa36ad 100644 --- 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_fb_helper *fb_helper, 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_fb_helper *fb_helper, 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; }