From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 AA3F63161AD; Thu, 16 Jul 2026 14:18:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784211491; cv=none; b=U+bDRvu2G3yftfnM8cXy5RHbVtNfMNmQPMyAdDuX3x5/ThSwlOGQb3XKkUepzssr2lNDh6Hl4/FPXNI6AWmwikPh8zgB4N3Q2lDMkPRnaBRtAIEsJ74b0VRpppMcMPfuL0L9FaH9MvDJYFOtGaYv/h1QV6T36duvTP6P6EboVnw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784211491; c=relaxed/simple; bh=Jl+cxZD21mFvsVnVSBCEK2n5iZY1x8TumMDJ/AKkb4w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=b3CWSg/vHK0M6Hs9NeTONlsKpTWD3fMP/KwUhlJYre3KUqay5unbUKwn6cY26CnOe3lqLkNuOD15x5+OJj9QV5Y2ZDU3jcpXXggmdHOrFTiZ5V9vBy5U/e92IgiJLYXL2b1OT3Jj4c1SsX7xG2AczrEtq2I5pHail9PK3yOKkPM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=u48I6dJS; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="u48I6dJS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1AB611F000E9; Thu, 16 Jul 2026 14:18:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784211490; bh=Yx6V3i4qLOwB20MuM3faQg4nmfwwSH5cUOBQ8l8PZSI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=u48I6dJSlbR5VB/qF6eOwg9ho8eBBtXTTpjj3AIrTbBaneroYArUhNtgvgjwQfkmq /TOq5ZE7+2Nqmss4bH1ymi9xrmlhUByNZbUEX7nYeKs80PaOMXXVyI9Q636QR3CEjT qQrHXzPXRbhanOClty0zQjYIcwKc6StZFpAkQiR8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bryam Vargas , Hans de Goede , Dmitry Torokhov Subject: [PATCH 6.18 447/480] Input: goodix - clamp the device-reported contact count Date: Thu, 16 Jul 2026 15:33:14 +0200 Message-ID: <20260716133054.492383131@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133044.672218725@linuxfoundation.org> References: <20260716133044.672218725@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bryam Vargas commit 5ed62a96e06be4e94b8296b7932afee550a70e04 upstream. goodix_ts_read_input_report() copies the number of touch points reported by the device into an on-stack buffer u8 point_data[2 + GOODIX_MAX_CONTACT_SIZE * GOODIX_MAX_CONTACTS]; which is sized for at most GOODIX_MAX_CONTACTS (10) contacts. The only runtime check bounds the per-interrupt count against ts->max_touch_num, but that value is taken verbatim from a 4-bit field of the device configuration block and is never clamped: ts->max_touch_num = ts->config[MAX_CONTACTS_LOC] & 0x0f; The nibble can be 0..15, so a malfunctioning, malicious or counterfeit controller (or an attacker tampering with the I2C bus) can advertise up to 15 contacts. goodix_ts_read_input_report() then accepts a touch_num of up to 15 and the second goodix_i2c_read() writes ts->contact_size * (touch_num - 1) bytes past the one-contact header into point_data - up to 30 bytes (45 with the 9-byte report format) beyond the 92-byte buffer: a stack out-of-bounds write. Clamp max_touch_num to GOODIX_MAX_CONTACTS, the number of contacts point_data[] is sized for, when reading it from the configuration. Fixes: a7ac7c95d468 ("Input: goodix - use max touch number from device config") Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas Reviewed-by: Hans de Goede Link: https://patch.msgid.link/20260612-b4-disp-6844625d-v1-1-df0aed080c9d@proton.me Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman --- drivers/input/touchscreen/goodix.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/input/touchscreen/goodix.c +++ b/drivers/input/touchscreen/goodix.c @@ -1057,7 +1057,8 @@ static void goodix_read_config(struct go } ts->int_trigger_type = ts->config[TRIGGER_LOC] & 0x03; - ts->max_touch_num = ts->config[MAX_CONTACTS_LOC] & 0x0f; + ts->max_touch_num = min(ts->config[MAX_CONTACTS_LOC] & 0x0f, + GOODIX_MAX_CONTACTS); x_max = get_unaligned_le16(&ts->config[RESOLUTION_LOC]); y_max = get_unaligned_le16(&ts->config[RESOLUTION_LOC + 2]);