From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A703FC433F5 for ; Mon, 14 Feb 2022 10:38:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242689AbiBNKi1 (ORCPT ); Mon, 14 Feb 2022 05:38:27 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:48006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242944AbiBNKet (ORCPT ); Mon, 14 Feb 2022 05:34:49 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A816B6463; Mon, 14 Feb 2022 02:01:58 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 631E8B80E0D; Mon, 14 Feb 2022 10:01:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EF6A8C340EF; Mon, 14 Feb 2022 10:01:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1644832916; bh=Gj3Z9M/ZYEBo4oID8ujH6W/lVH/mp2oAgAzRkJJzenA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qvRHiilpnFwRC8LbEQiSTZBDZSLJg3a0HHWYXubVjQA8gkt0a5VlkKgZeGa1vAjZo kDBDe4m1Xg4UK9FmZW9YVlEqZ0VmlxYPsnUmLvkLhSIRlw2vcHbIYV/zZ6ysNYiJ2M Or9DqDgDcMBKxoEKvTIU0fiLrUMel6Q2/1xf7xiY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Heiner Kallweit , Jonas Malaco Subject: [PATCH 5.16 165/203] eeprom: ee1004: limit i2c reads to I2C_SMBUS_BLOCK_MAX Date: Mon, 14 Feb 2022 10:26:49 +0100 Message-Id: <20220214092515.850069036@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220214092510.221474733@linuxfoundation.org> References: <20220214092510.221474733@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jonas Malaco commit c0689e46be23160d925dca95dfc411f1a0462708 upstream. Commit effa453168a7 ("i2c: i801: Don't silently correct invalid transfer size") revealed that ee1004_eeprom_read() did not properly limit how many bytes to read at once. In particular, i2c_smbus_read_i2c_block_data_or_emulated() takes the length to read as an u8. If count == 256 after taking into account the offset and page boundary, the cast to u8 overflows. And this is common when user space tries to read the entire EEPROM at once. To fix it, limit each read to I2C_SMBUS_BLOCK_MAX (32) bytes, already the maximum length i2c_smbus_read_i2c_block_data_or_emulated() allows. Fixes: effa453168a7 ("i2c: i801: Don't silently correct invalid transfer size") Cc: stable@vger.kernel.org Reviewed-by: Heiner Kallweit Signed-off-by: Jonas Malaco Link: https://lore.kernel.org/r/20220203165024.47767-1-jonas@protocubo.io Signed-off-by: Greg Kroah-Hartman --- drivers/misc/eeprom/ee1004.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/misc/eeprom/ee1004.c +++ b/drivers/misc/eeprom/ee1004.c @@ -114,6 +114,9 @@ static ssize_t ee1004_eeprom_read(struct if (offset + count > EE1004_PAGE_SIZE) count = EE1004_PAGE_SIZE - offset; + if (count > I2C_SMBUS_BLOCK_MAX) + count = I2C_SMBUS_BLOCK_MAX; + return i2c_smbus_read_i2c_block_data_or_emulated(client, offset, count, buf); }