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 D20AD43148D; Thu, 16 Jul 2026 14:35:07 +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=1784212509; cv=none; b=Q2bAj4EySFW0cae9yQIkOn0ueGyfznNMBQKw28fUeULxaSnxZKk7lO40eLU+OaMJYTIh7Fm/UCtkOv/ELvV9ahKP0JzIdDQIjoJcwGEGWRBmvSiQluJlE0ATtLu7pfgueQgPTYpBQhrkne9A1cCWVkrIIH6OxYx+1eRYB0DXLPQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784212509; c=relaxed/simple; bh=ojpFe6uNPmjbfSKj6zg9dmF4fYDL6O2QYR/XgdLZ8vY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=S7MtfLt0D5hPs3BX8sbMGnm951zjRd7oucU0QGjYm22Q8cxQn1rfKk5Hd15/C1M017BTd8tQMuC47bm0YO1EXsLRfeiF1nz3Z3b2EbL7JU21rTmn7WTgfTvf3+FMGuWaPKD3PLAA8yE81+3OarMa5s1FQSxlkBIxk5ZRjPQ0DiU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=M+kjlF0p; 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="M+kjlF0p" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 342971F00A3D; Thu, 16 Jul 2026 14:35:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784212507; bh=xQcSDvGlENc5EZLjIcfX/f+UNxTABS5UueHdBN4OU4g=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=M+kjlF0ps+1RjGvFMmyeisl8gq2Kqoo8/JXcStohqmtTn4N+I2lSvXDk3681xfCSL ugJ3wRF5SGS4ZL+n2iHYi8y61hazlEbHd+1HKu7LBgFRKfNnymuNUXF1Ot3pyrbCXJ LD/3c8F+O2CoQ1qfRoHgh50+xKdqrQkacwhANjk4= 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 6.12 334/349] Input: goodix - clamp the device-reported contact count Date: Thu, 16 Jul 2026 15:34:28 +0200 Message-ID: <20260716133040.788456300@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133033.287196923@linuxfoundation.org> References: <20260716133033.287196923@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 6.12-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 @@ -1056,7 +1056,8 @@ 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]);