From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8533A4AD7CB for ; Thu, 1 Oct 2026 22:26:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790893592; cv=none; b=ZEGJskaYjTWm/paVYIxaWYvOxga20y9uyNCPEd1RRYg0GMr8H/zP6827Nwg2+jHPwsE/waJ7M2Zid9WP8ef3m+zBV4HFnbUZJZOjKpnEzCMn0hzRTcfk/7qdI3JcFJ0dyikm9QRdLbdXIpWppRRFZMfmw0F8h3dojVPG4zEA9Uc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790893592; c=relaxed/simple; bh=a502TtNr4VrqlVPyn8osIApydd3Tk0Kn8V2v4c6+miI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=NBg9VBu+7LdZTm6HgC9ljb9E8pnS/xV7OG85HWSBwAvDhaE2Odzc3IqXzLpoezr9OeuV4prTjwwuEyyzuhX2Am3JWFsDLcKfiyKQuLsgKlV1d1dtjzB7E72qqjeAm4C/kmGcOte2RA3rK1V3emGIUt6A8xwMWHGGohOXECisTrI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=R5njMsEu; arc=none smtp.client-ip=148.251.105.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="R5njMsEu" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1790893588; bh=a502TtNr4VrqlVPyn8osIApydd3Tk0Kn8V2v4c6+miI=; h=From:Date:Subject:To:Cc:From; b=R5njMsEuvwtWrT3nuNcNAqnN7l86Cb0gO1V8EIPubq4kIcYkl/scjSzglPvQbtSEE X53ZDDF7hp550uh9GfFLLkba8ao/LfCvdOz4tYlo+xIQOi+VPU/3E0bK133JlC22YL YVUHsnuwknLKrXuNHP04RDxhHFxTA1r9W1fSwpU4s/cfNo2L5ui1bW9PtPxIuBisq1 //jlvZwXCgYluD4QyuJmcWE8nBHMBzCpPstaWXLyAUy8RhF5l/NyORi0y4hIorlFmT I0ENvy0vMwxKeFx2Lc3gSWhIv7ZIFvnXcEXD8FMChBtXBFvYrJcSp0SYG4IchXMvmW ZJ9R3pN/uZhow== Received: from localhost (unknown [100.64.0.241]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange secp256r1 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: cristicc) by bali.collaboradmins.com (Postfix) with ESMTPSA id 72AA917E005A; Fri, 02 Oct 2026 00:26:28 +0200 (CEST) From: Cristian Ciocaltea Date: Fri, 02 Oct 2026 01:26:14 +0300 Subject: [PATCH] drm/display: hdmi: Prevent NULL pointer dereference in sync_scdc() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261002-hdmi-sync-scdc-fix-deref-v1-1-d99b4f544dd4@collabora.com> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/yXMQQqDQAyF4atI1g3MTItKr1K6sEnUCE7LRMUi3 r1TXX4P3r+BSVIxuBcbJFnU9B0z/KUA6pvYCSpnQ3Ch9M4F7HlUtG8kNGLCVldkSdKir/3VVRX zrW4g3z951PVIP56nbX4NQtO/B/v+A8/DOw98AAAA X-Change-ID: 20261002-hdmi-sync-scdc-fix-deref-1813077dd48a To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter Cc: kernel@collabora.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Dan Carpenter X-Mailer: b4 0.15.2 The connector pointer is used to initialize the local variables hdmi and dev before the NULL check takes place, leading to the following Smatch complaint: drivers/gpu/drm/display/drm_hdmi_helper.c:663 drm_connector_hdmi_sync_scdc() warn: variable dereferenced before check 'connector' (see line 657) Move those initializations after the sanity check to avoid a potential NULL pointer dereference. Fixes: d653818324ed ("drm/display: hdmi: Add HDMI 2.0 scrambling management helpers") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/all/arJo7A7L5hud3tyc@stanley.mountain/ Signed-off-by: Cristian Ciocaltea --- drivers/gpu/drm/display/drm_hdmi_helper.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/display/drm_hdmi_helper.c b/drivers/gpu/drm/display/drm_hdmi_helper.c index f85cce3d6254..872f7e32e8d2 100644 --- a/drivers/gpu/drm/display/drm_hdmi_helper.c +++ b/drivers/gpu/drm/display/drm_hdmi_helper.c @@ -653,9 +653,9 @@ EXPORT_SYMBOL(drm_connector_hdmi_disable_scrambling); int drm_connector_hdmi_sync_scdc(struct drm_connector *connector, bool plugged, struct drm_modeset_acquire_ctx *ctx) { - struct drm_connector_hdmi *hdmi = &connector->hdmi; - struct drm_device *dev = connector->dev; + struct drm_connector_hdmi *hdmi; struct drm_connector_state *conn_state; + struct drm_device *dev; struct drm_crtc *crtc; u8 config; int ret; @@ -663,6 +663,9 @@ int drm_connector_hdmi_sync_scdc(struct drm_connector *connector, bool plugged, if (!connector || !plugged || !ctx) return 0; + hdmi = &connector->hdmi; + dev = connector->dev; + /* * This is normally part of .detect_ctx() call path, which already holds * connection_mutex through @ctx. However, re-acquiring it with the --- base-commit: 37b346eab23aead52d17a8fa687056bfc651a416 change-id: 20261002-hdmi-sync-scdc-fix-deref-1813077dd48a