From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.12]) (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 A44003D1CC3; Wed, 19 Aug 2026 07:28:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787124522; cv=none; b=JowZSSCUkWWpVEMtx6VhH585fp+6b/IzKdxSwz43sfaLECF5Nh97MySspG2wcXHQFSTV4bFEHTesCz4hQQVx/b9BEeiJT0iMcDBlHqE2GuvQIPTyblZs+NoemfgGyAx420d2WwwW0NOI/Uw3+nplUJXVweebNH/XcoCmqRH6LSY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787124522; c=relaxed/simple; bh=bjxkUigIQF/FLCtfFhnV9suBNyW3HXulGmclH/su+eg=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=Z+WoW6t5ViBUaWvNhQFbx3fpMg115+scJx6OzXNsppRfkr+rJGC92FpM8c/ntxod3AqSEG5/OwzcYR2N/BzR4g9nSelXh0eFi+3PbGGsiHVzXy6yUtl62g9bsBw+UgQrVQcr1mcIE7Uq3WY2qSApkOag/zKS1Of8apNYUpa4/Wk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=HW2DpUTy; arc=none smtp.client-ip=192.198.163.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="HW2DpUTy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1787124520; x=1818660520; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=bjxkUigIQF/FLCtfFhnV9suBNyW3HXulGmclH/su+eg=; b=HW2DpUTyJRLrKnZiCZHJ6ae7/m1q5r5nNIACc/Z+z4FS9SmvxsEQScaB 85+SAAwbyu3SEEJXA9/HEntXugNUosxBEJ2EDDHb/VIKMYAkjLTdOOyvZ GQ3i53NJnsns+M0XZmGveDyK8me1nM/9RYS0m+iI269S71KqgmVGvuSFL Sr8L0jVU+o6I7LcLRoi1iQ6acQG26Q1ma9t5NW+X7J9VhOb/j4gL4BV2R KWnVfFTQVxbtifPeMucTH+WVwV7E412ZlmPVX3iIUuBKxuvYRzupgl5Qq pxRl0bnuCGDI6N0XPWywqCGIUuCDBW7AouKbyF2p00S9etnwfJlZEav1S w==; X-CSE-ConnectionGUID: AgQLnkJ2R+WwpYJApCLuiw== X-CSE-MsgGUID: ECJPR5UwTS6OE+tnCxetkw== X-IronPort-AV: E=McAfee;i="6800,10657,11879"; a="91439176" X-IronPort-AV: E=Sophos;i="6.25,231,1779174000"; d="scan'208";a="91439176" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by fmvoesa106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Aug 2026 00:28:39 -0700 X-CSE-ConnectionGUID: FrrgiAu2Ri62gIJolx8YbQ== X-CSE-MsgGUID: rJVwAm93To6OeUUeu/n7Og== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,231,1779174000"; d="scan'208";a="263729170" Received: from tester.sh.intel.com ([10.112.106.126]) by orviesa006.jf.intel.com with ESMTP; 19 Aug 2026 00:28:37 -0700 From: Tao Yu To: Ruben Wauters Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Tao Yu , syzbot+9ae8e7884e451eaed5b4@syzkaller.appspotmail.com Subject: [PATCH] drm/gud: validate TV mode names before creating enum property Date: Wed, 19 Aug 2026 15:28:35 +0800 Message-Id: <20260819072835.4074130-1-tao1.yu@intel.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The GUD protocol returns TV mode names as fixed-size GUD_CONNECTOR_TV_MODE_NAME_LEN entries and requires each name to be NUL-terminated. gud_connector_add_tv_mode() currently passes each fixed-size entry directly to drm_mode_create_tv_properties_legacy(), which eventually reaches drm_property_add_enum() and strlen(). If a device returns an entry without a terminating NUL byte, strlen() reads past the end of the slot and can run beyond the allocated buffer, triggering an out-of-bounds read. Validate that each returned TV mode name contains a NUL terminator within its fixed-size slot before passing it to the DRM property code. If a malformed entry is found, reject the device response with -EIO. This fixes the out-of-bounds read without changing the handling of valid devices, and avoids silently truncating malformed protocol data. Reported-by: syzbot+9ae8e7884e451eaed5b4@syzkaller.appspotmail.com Fixes: 40e1a70b4aed ("drm: Add GUD USB Display driver") Signed-off-by: Tao Yu --- drivers/gpu/drm/gud/gud_connector.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/gud/gud_connector.c b/drivers/gpu/drm/gud/gud_connector.c index ea0cca58b7c89..8141c3a1e30ad 100644 --- a/drivers/gpu/drm/gud/gud_connector.c +++ b/drivers/gpu/drm/gud/gud_connector.c @@ -396,8 +396,16 @@ static int gud_connector_add_tv_mode(struct gud_device *gdrm, struct drm_connect } num_modes = ret / GUD_CONNECTOR_TV_MODE_NAME_LEN; - for (i = 0; i < num_modes; i++) - modes[i] = &buf[i * GUD_CONNECTOR_TV_MODE_NAME_LEN]; + for (i = 0; i < num_modes; i++) { + char *mode = &buf[i * GUD_CONNECTOR_TV_MODE_NAME_LEN]; + + if (!memchr(mode, '\0', GUD_CONNECTOR_TV_MODE_NAME_LEN)) { + ret = -EIO; + goto free; + } + + modes[i] = mode; + } ret = drm_mode_create_tv_properties_legacy(connector->dev, num_modes, modes); free: -- 2.34.1