From bd64240dc88caaf7b96dd869f36f165f51b52039 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Fri, 3 Apr 2026 13:53:54 -0700 Subject: [PATCH] drm/fb-helper: Fix a locking bug in an error path MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The name of the function __drm_fb_helper_initial_config_and_unlock() and also the comment above that function make it clear that all code paths in this function should unlock fb_helper->lock before returning. Add a mutex_unlock() call in the only code path where it is missing. This has been detected by the Clang thread-safety analyzer. Cc: Thomas Zimmermann Cc: Christian König # radeon Cc: Dmitry Baryshkov # msm Cc: Javier Martinez Canillas Fixes: 63c971af4036 ("drm/fb-helper: Allocate and release fb_info in single place") Signed-off-by: Bart Van Assche Signed-off-by: Thomas Zimmermann Reviewed-by: Thomas Zimmermann Link: https://patch.msgid.link/20260403205355.1181984-1-bvanassche@acm.org --- drivers/gpu/drm/drm_fb_helper.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 845c63ca15b5..0d2d0311dee2 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1626,8 +1626,10 @@ __drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper) drm_client_modeset_probe(&fb_helper->client, width, height); info = drm_fb_helper_alloc_info(fb_helper); - if (IS_ERR(info)) + if (IS_ERR(info)) { + mutex_unlock(&fb_helper->lock); return PTR_ERR(info); + } ret = drm_fb_helper_single_fb_probe(fb_helper); if (ret < 0) {