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 271EE4A1387; Mon, 31 Aug 2026 14:08:03 +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=1788185284; cv=none; b=riPqthdaRW4F/lluBN/8vAYlVy9cAi+xJEA3bRrp1fFFu/ZQ4y1MyXnLJjBhVDLvtYVNrXrGXEd/RWB8C9NNN2R6TI79AQ6puX18MXpVL0bu7c4VKu4Iv7L43cus+7XIv5o1wpQ8nFReJegYAf7MoLkpZL79iz7pV+d9DjopUPo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788185284; c=relaxed/simple; bh=4zy/sTIsUmadpJ/nQUO5XsIiJthLzPcRk5K+HHwgbus=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=L1LkFOJZiNLmSzfrDXILckj6O3R8PxOKhOuNCxajrqISJQZzWEoQK90PudymxVX54/pE2r6iLY9AVtRgvMTyoG2nW908huxSdB3H6LW0w7KbFOq+1WMx8AVEXw99pdb4jbyqkN5x6J7cNi0xdgvM6Ns4cuXwfIUOkAw5OwDYZeQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=N22r+Mqf; 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="N22r+Mqf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75F1C1F000E9; Mon, 31 Aug 2026 14:08:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788185283; bh=WVygwbhV/B4dQbV831D7kQTc+GJLtwJcCZgO9ivB26I=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=N22r+MqfRW7ywB+rCd0h+8pAV11I4nwUJoIOW/7etMw8IrTbRA0bruPqujWTIrrLW r3BtErhslF0FZlJH+qPh1aalIJF5zbnxUU6ETRyj6yPgSjoqNqvyQDNk66/+6xOlpv kMa9QEc3sQBZZk7LWmPSGqB2phWmi32VZDkgXcfE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiale Yao , Johan Hovold Subject: [PATCH 5.10 40/43] USB: serial: option: fix slab OOB read in interrupt URB callback Date: Mon, 31 Aug 2026 15:35:48 +0200 Message-ID: <20260831133400.619312351@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260831133358.571886287@linuxfoundation.org> References: <20260831133358.571886287@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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiale Yao commit 885d802f544ca7bfa8f3984d94233cce715bb6b3 upstream. The interrupt URB buffer is allocated in setup_port_interrupt_in() based on the endpoint's wMaxPacketSize: buffer_size = usb_endpoint_maxp(epd); port->interrupt_in_buffer = kmalloc(buffer_size, GFP_KERNEL); When a USB device declares wMaxPacketSize = 8 on its interrupt IN endpoint, the buffer is allocated from kmalloc-8 cache (exactly 8 bytes). If the device sends a short packet (actual_length < wMaxPacketSize), the URB completes with status == 0 and the callback proceeds to read: data[sizeof(struct usb_ctrlrequest)] which evaluates to data[8], accessing 1 byte beyond the allocated 8-byte buffer. This results in a slab out-of-bounds read. Fix this by adding the missing bounds check: first verify that the actual length is large enough to contain the struct usb_ctrlrequest header before accessing req_pkt->bRequestType and req_pkt->bRequest, and then verify that there is an additional byte for the modem signal state before reading data[sizeof(struct usb_ctrlrequest)] inside the conditional. Use sizeof(*req_pkt) instead of sizeof(struct usb_ctrlrequest) for consistency. Assisted-by: Claude:deepseek-v4-pro Signed-off-by: Jiale Yao Fixes: 58cfe9113e48 ("[PATCH] USB: add Option Card driver") Cc: stable@vger.kernel.org # v2.6.12 [ johan: use dev_err(); split signals declaration and initialisation ] Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/option.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) --- a/drivers/usb/serial/option.c +++ b/drivers/usb/serial/option.c @@ -2693,12 +2693,26 @@ static void option_instat_callback(struc dev_dbg(dev, "%s: NULL req_pkt\n", __func__); return; } + + if (urb->actual_length < sizeof(*req_pkt)) { + dev_err(dev, "%s: short packet: %u bytes\n", __func__, + urb->actual_length); + return; + } + if ((req_pkt->bRequestType == 0xA1) && (req_pkt->bRequest == 0x20)) { + unsigned char signals; int old_dcd_state; - unsigned char signals = *((unsigned char *) - urb->transfer_buffer + - sizeof(struct usb_ctrlrequest)); + + if (urb->actual_length < sizeof(*req_pkt) + 1) { + dev_err(dev, "%s: short interrupt transfer: %u bytes\n", + __func__, urb->actual_length); + return; + } + + signals = *((unsigned char *)urb->transfer_buffer + + sizeof(*req_pkt)); dev_dbg(dev, "%s: signal x%x\n", __func__, signals);