From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f53.google.com (mail-wm1-f53.google.com [209.85.128.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7FDA323EABC for ; Sat, 11 Apr 2026 06:24:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775888686; cv=none; b=gV8TEMJtf+VmAZpXGaXNf1P1eFzZ3byMTbkg1RApo4CS9hEAw+/IKTI6rov26qcLZEwXbriYKRPxCM0F0u6a3L5OrGzzRcy1l80qLtSxa9ZgGdjpvFyvyi8v7URs1DHC3VJ/ljuxGpJ49WRYcSjDaedURaRYXuLGf7z6punFMRc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775888686; c=relaxed/simple; bh=3snsAoIMBzCHRg/GUGzBNUgkch32WkivELDaPo93WgU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=qyRZG67RyyTMQduC9uvYWiSPP6PRwOdhyB80jzh/oglJtiL/tGgssHygHwbNf/lwXKgUCeqva1+anFVzgvtcIb0s0slgzVUzS0k9UEGwxbfzZ7ykukgYAenWPBTnCpbuVfpxhtwkfRMNs0WcTI0Wj3mikfg5bq33mHFeR4D8xos= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=czMMNgVW; arc=none smtp.client-ip=209.85.128.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="czMMNgVW" Received: by mail-wm1-f53.google.com with SMTP id 5b1f17b1804b1-488a9033b2cso32268395e9.2 for ; Fri, 10 Apr 2026 23:24:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1775888684; x=1776493484; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=bfMaeNbFtgkbM0ewh/h9BevALASkRdIGD35O9poxD+w=; b=czMMNgVWLsw/fED9Yg3PRri9fig7TrxzTQE2Yw2cJ4AO4TXGnkWZXFwz+YwX6SQAtj 5LhWYUqTIhYYkVSzZzhS5jyNrBDIjw0otNMeCHvTv054knSAXPSDjcvk7ni3Jy73ZZ8F r0mwooxbuj6roQmsgsLkHaJjtSswLmNMxpZRLj4nxa341unwlzTZG3pnzoAAmMkABfX4 k+eQrtOaCGnw2y8c/FTRTZX82g8D8B5+dCjmc8bg/zD7rNek/L3bPNJkwXzqjKIRdAnJ Ue4KrLBfsaWDV2pFpYWgyN2G2APes0u0aWPGsj8SXF1VbjkmwwZtg4MHMMwbckhO49Py mSqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775888684; x=1776493484; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=bfMaeNbFtgkbM0ewh/h9BevALASkRdIGD35O9poxD+w=; b=efLvxiBOW4wvhcrH9FeIYlZwV2QSxdccdVgQExPCmkohfjpXqYdMbWy/KGGZ5JjgZd THVQPYWMhlmxjqCVSeJKfLiLmv/QBxwmuZCXSEeBRsb2lqciFpVfxIaYD1rh/kEu+boI vxH3I4KdAzT+Jv0O/IjSnJrWZl30ufV3+eu9xQ+NkkbHDNoPCi2Qt19zQ7AYF8OGqIrS 3LRYOG1mUjzqZe1tnk6p+t3FVR2O1HHM+n9vrcYfZ3xoMNG/PyD3CeEnz9lnTCBVlGZB SZfxvFJrSsJGnUp1adojMacqjtCZBYsT3LO8cWEt3xjNHxqPyXuPFTanoY5MA4oZ+QE3 bNIA== X-Gm-Message-State: AOJu0Yx0Q+mgZrV/eweSGqvmIp1kofv+UZw1QlNPr05qUy0S20Cqd52B U2YOBM2uYLilzihSSvNAIYpvc9VJHeD1jNRBtO1v5UFMN2XCQsfoCQWD X-Gm-Gg: AeBDieuRx5IznX7r7aZgEPRfQc6bdfzM4HoiPkg8VreI6wTjvkvJyD7fPBvWaHt1Nqs IRRkGCD+j+i53UvxBZDKzthZL0T5ajqNTMhv9HZix5UdqLDK4eToBAc9bH9jJjLimNatu6I1hvA E9JSYR/3N1KqQ/0TufnQ5vvJBxLFn/roBwsoFcsBC5ZK7iBa0fSRCJIyvTnEqlfhjZxpROqNhui aCUIIociXxoBAN7PlsHal2NUCei3rgxE/cLnbg4xr2x22vl+gnHVJpno0Ev3+9WizHNSfZSBB+O YXMAnPYNzViT4yU1110arh8TrMejAw7XWP+kmPub0THnEWidA0VWWoEiGY2MCUU0oe0Lt7wVOy+ UV6eOmmr5zq+3OxTEissoHbu5vtzIMedLcoRQZl0vtecqbony4orkwUWi2ExkTeYLZabpExcwVl yeHS1Ct4SJtPY/n5q1rTsCWdITI0BFn3Wm9h2RE3gT04lE82NVB92mHKOgChiGBeZgx1st X-Received: by 2002:a05:600c:a415:b0:485:419c:4eba with SMTP id 5b1f17b1804b1-488d67bf7abmr58956365e9.1.1775888683705; Fri, 10 Apr 2026 23:24:43 -0700 (PDT) Received: from x2-evb57.xsight.ent (genie03-172-158.inter.net.il. [213.8.172.158]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-488d58bb830sm127720075e9.7.2026.04.10.23.24.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Apr 2026 23:24:43 -0700 (PDT) From: Michael Zaidman To: jikos@kernel.org, benjamin.tissoires@redhat.com Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, sebasjosue84@gmail.com, Michael Zaidman Subject: [PATCH v2] HID: ft260: validate i2c input report length Date: Sat, 11 Apr 2026 09:24:37 +0300 Message-Id: <20260411062437.279838-1-michael.zaidman@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-input@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add two checks to ft260_raw_event() to prevent out-of-bounds reads from malicious or malfunctioning devices: First, reject reports shorter than the 2-byte header (report ID + length fields). Without this, even accessing xfer->length on a 1-byte report is an OOB read. Second, validate xfer->length against the actual data capacity of the received HID report. Each I2C data report ID (0xD0 through 0xDE) defines a different report size in the HID descriptor, so the available payload varies per report. A corrupted length field could cause memcpy to read beyond the report buffer. Reported-by: Sebastián Josué Alba Vives Signed-off-by: Michael Zaidman --- Changes in v2: - Add minimum report size check before accessing header fields to prevent OOB read on truncated reports (size < 2) Tested on FT260 with I2C-attached EEPROM (24c02) behind PCA9548 mux switches. Verified reads of various sizes (1-4 bytes using report ID 0xD0, and larger reads using higher report IDs) with debug tracing enabled, confirming xfer->length is correctly validated against the HID report size for each report ID. --- drivers/hid/hid-ft260.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index 333341e80b0e..70e2eedb465a 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -1068,10 +1068,22 @@ static int ft260_raw_event(struct hid_device *hdev, struct hid_report *report, struct ft260_device *dev = hid_get_drvdata(hdev); struct ft260_i2c_input_report *xfer = (void *)data; + if (size < offsetof(struct ft260_i2c_input_report, data)) { + hid_err(hdev, "short report %d\n", size); + return -1; + } + if (xfer->report >= FT260_I2C_REPORT_MIN && xfer->report <= FT260_I2C_REPORT_MAX) { - ft260_dbg("i2c resp: rep %#02x len %d\n", xfer->report, - xfer->length); + ft260_dbg("i2c resp: rep %#02x len %d size %d\n", + xfer->report, xfer->length, size); + + if (xfer->length > size - + offsetof(struct ft260_i2c_input_report, data)) { + hid_err(hdev, "report %#02x: length %d exceeds HID report size\n", + xfer->report, xfer->length); + return -1; + } if ((dev->read_buf == NULL) || (xfer->length > dev->read_len - dev->read_idx)) { -- 2.25.1