From patchwork Sat Dec 10 16:23:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Zetao X-Patchwork-Id: 633052 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 E32E6C4332F for ; Sat, 10 Dec 2022 15:19:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229715AbiLJPTv (ORCPT ); Sat, 10 Dec 2022 10:19:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229524AbiLJPTu (ORCPT ); Sat, 10 Dec 2022 10:19:50 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7AF6412AB9; Sat, 10 Dec 2022 07:19:48 -0800 (PST) Received: from kwepemi500012.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4NTs3w3X5qzJqKw; Sat, 10 Dec 2022 23:18:52 +0800 (CST) Received: from huawei.com (10.175.101.6) by kwepemi500012.china.huawei.com (7.221.188.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Sat, 10 Dec 2022 23:19:16 +0800 From: Li Zetao To: CC: , , , , , , , , , , Subject: [PATCH v2] rtlwifi: rtl8821ae: Fix global-out-of-bounds bug in _rtl8812ae_phy_set_txpower_limit() Date: Sun, 11 Dec 2022 00:23:36 +0800 Message-ID: <20221210162336.1383856-1-lizetao1@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemi500012.china.huawei.com (7.221.188.12) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org There is a global-out-of-bounds reported by KASAN: BUG: KASAN: global-out-of-bounds in _rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae] Read of size 1 at addr ffffffffa0773c43 by task NetworkManager/411 CPU: 6 PID: 411 Comm: NetworkManager Tainted: G D 6.1.0-rc8+ #144 e15588508517267d37 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), Call Trace: ... kasan_report+0xbb/0x1c0 _rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae] rtl8821ae_phy_bb_config.cold+0x346/0x641 [rtl8821ae] rtl8821ae_hw_init+0x1f5e/0x79b0 [rtl8821ae] ... The root cause of the problem is that the comparison order of "prate_section" in _rtl8812ae_phy_set_txpower_limit() is wrong. The _rtl8812ae_eq_n_byte() is used to compare the first n bytes of the two strings from tail to head, which causes the problem. In the _rtl8812ae_phy_set_txpower_limit(), it was originally intended to meet this requirement by carefully designing the comparison order. For example, "pregulation" and "pbandwidth" are compared in order of length from small to large, first is 3 and last is 4. However, the comparison order of "prate_section" dose not obey such order requirement, therefore when "prate_section" is "HT", when comparing from tail to head, it will lead to access out of bounds in _rtl8812ae_eq_n_byte(). As mentioned above, the _rtl8812ae_eq_n_byte() has the same function as strcmp(), so just strcmp() is enough. Fix it by replacing _rtl8812ae_eq_n_byte() with strcmp(). Although it can be fixed by adjusting the comparison order of "prate_section", this may cause the value of "rate_section" to not be from 0 to 5. In addition, commit "21e4b0726dc6" not only moved driver from staging to regular tree, but also added setting txpower limit function during the driver config phase, so the problem was introduced by this commit. Fixes: 21e4b0726dc6 ("rtlwifi: rtl8821ae: Move driver from staging to regular tree") Signed-off-by: Li Zetao --- v1 was posted at: https://lore.kernel.org/all/20221207152319.3135500-1-lizetao1@huawei.com/ v1 -> v2: delete the third parameter of _rtl8812ae_eq_n_byte() and use strcmp to replace loop comparison. .../wireless/realtek/rtlwifi/rtl8821ae/phy.c | 51 ++++++++----------- 1 file changed, 22 insertions(+), 29 deletions(-) diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c b/drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c index a29321e2fa72..14b569d7d8fa 100644 --- a/drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c @@ -1598,16 +1598,9 @@ static bool _rtl8812ae_get_integer_from_string(const char *str, u8 *pint) return true; } -static bool _rtl8812ae_eq_n_byte(const char *str1, const char *str2, u32 num) +static bool _rtl8812ae_eq_n_byte(const char *str1, const char *str2) { - if (num == 0) - return false; - while (num > 0) { - num--; - if (str1[num] != str2[num]) - return false; - } - return true; + return strcmp(str1, str2) == 0; } static s8 _rtl8812ae_phy_get_chnl_idx_of_txpwr_lmt(struct ieee80211_hw *hw, @@ -1659,42 +1652,42 @@ static void _rtl8812ae_phy_set_txpower_limit(struct ieee80211_hw *hw, power_limit = power_limit > MAX_POWER_INDEX ? MAX_POWER_INDEX : power_limit; - if (_rtl8812ae_eq_n_byte(pregulation, "FCC", 3)) + if (_rtl8812ae_eq_n_byte(pregulation, "FCC")) regulation = 0; - else if (_rtl8812ae_eq_n_byte(pregulation, "MKK", 3)) + else if (_rtl8812ae_eq_n_byte(pregulation, "MKK")) regulation = 1; - else if (_rtl8812ae_eq_n_byte(pregulation, "ETSI", 4)) + else if (_rtl8812ae_eq_n_byte(pregulation, "ETSI")) regulation = 2; - else if (_rtl8812ae_eq_n_byte(pregulation, "WW13", 4)) + else if (_rtl8812ae_eq_n_byte(pregulation, "WW13")) regulation = 3; - if (_rtl8812ae_eq_n_byte(prate_section, "CCK", 3)) + if (_rtl8812ae_eq_n_byte(prate_section, "CCK")) rate_section = 0; - else if (_rtl8812ae_eq_n_byte(prate_section, "OFDM", 4)) + else if (_rtl8812ae_eq_n_byte(prate_section, "OFDM")) rate_section = 1; - else if (_rtl8812ae_eq_n_byte(prate_section, "HT", 2) && - _rtl8812ae_eq_n_byte(prf_path, "1T", 2)) + else if (_rtl8812ae_eq_n_byte(prate_section, "HT") && + _rtl8812ae_eq_n_byte(prf_path, "1T")) rate_section = 2; - else if (_rtl8812ae_eq_n_byte(prate_section, "HT", 2) && - _rtl8812ae_eq_n_byte(prf_path, "2T", 2)) + else if (_rtl8812ae_eq_n_byte(prate_section, "HT") && + _rtl8812ae_eq_n_byte(prf_path, "2T")) rate_section = 3; - else if (_rtl8812ae_eq_n_byte(prate_section, "VHT", 3) && - _rtl8812ae_eq_n_byte(prf_path, "1T", 2)) + else if (_rtl8812ae_eq_n_byte(prate_section, "VHT") && + _rtl8812ae_eq_n_byte(prf_path, "1T")) rate_section = 4; - else if (_rtl8812ae_eq_n_byte(prate_section, "VHT", 3) && - _rtl8812ae_eq_n_byte(prf_path, "2T", 2)) + else if (_rtl8812ae_eq_n_byte(prate_section, "VHT") && + _rtl8812ae_eq_n_byte(prf_path, "2T")) rate_section = 5; - if (_rtl8812ae_eq_n_byte(pbandwidth, "20M", 3)) + if (_rtl8812ae_eq_n_byte(pbandwidth, "20M")) bandwidth = 0; - else if (_rtl8812ae_eq_n_byte(pbandwidth, "40M", 3)) + else if (_rtl8812ae_eq_n_byte(pbandwidth, "40M")) bandwidth = 1; - else if (_rtl8812ae_eq_n_byte(pbandwidth, "80M", 3)) + else if (_rtl8812ae_eq_n_byte(pbandwidth, "80M")) bandwidth = 2; - else if (_rtl8812ae_eq_n_byte(pbandwidth, "160M", 4)) + else if (_rtl8812ae_eq_n_byte(pbandwidth, "160M")) bandwidth = 3; - if (_rtl8812ae_eq_n_byte(pband, "2.4G", 4)) { + if (_rtl8812ae_eq_n_byte(pband, "2.4G")) { ret = _rtl8812ae_phy_get_chnl_idx_of_txpwr_lmt(hw, BAND_ON_2_4G, channel); @@ -1718,7 +1711,7 @@ static void _rtl8812ae_phy_set_txpower_limit(struct ieee80211_hw *hw, regulation, bandwidth, rate_section, channel_index, rtlphy->txpwr_limit_2_4g[regulation][bandwidth] [rate_section][channel_index][RF90_PATH_A]); - } else if (_rtl8812ae_eq_n_byte(pband, "5G", 2)) { + } else if (_rtl8812ae_eq_n_byte(pband, "5G")) { ret = _rtl8812ae_phy_get_chnl_idx_of_txpwr_lmt(hw, BAND_ON_5G, channel);