From patchwork Thu Jan 4 14:39:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Alexis_Lothor=C3=A9?= X-Patchwork-Id: 760678 Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net [217.70.183.201]) (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 9C58B2374B; Thu, 4 Jan 2024 14:41:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="M5+w+PGf" Received: by mail.gandi.net (Postfix) with ESMTPSA id D3E861BF206; Thu, 4 Jan 2024 14:41:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1704379285; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xF5ufSSvoks3261aOCEfIfrU7GTgqssBEJuBdMc7zSc=; b=M5+w+PGf+TFvXeymA8x/IEV45gTLY4Nxmb0OGP6MgVCUAB4Hwy14GqSj67dK6KKGiGQAQO /+26+htWmLCphBJv3xk65c6N+S0/TcwOXXNs1Vn09iYv0K3JEZRydW4xE8tW+IDIo0bMCY +SzE+stg5KGI5mPGJS259EAW6R3xyhiDjzAcVg33LqFxeFLr9dNXsBvQftYn2EXzzP5Hn/ oZMPgHuHOZc2UapmVf/bu0iSKSWSuyt5Le2GJWWqASgP13aEYT9xMAIaCXUe+KfV5Mnmu1 jJU1gUV2Tye03yOa1b6YcKjXTDKrgnjDWvRpjnHqvUc0DMmPepTUeThRnCDo8Q== From: =?utf-8?q?Alexis_Lothor=C3=A9?= To: linux-wireless@vger.kernel.org Cc: Ajay Singh , Claudiu Beznea , Kalle Valo , Thomas Petazzoni , linux-kernel@vger.kernel.org Subject: [PATCH 2/2] wifi: wilc1000: fix RCU usage in connect path Date: Thu, 4 Jan 2024 15:39:25 +0100 Message-ID: <20240104143925.194295-3-alexis.lothore@bootlin.com> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20240104143925.194295-1-alexis.lothore@bootlin.com> References: <20240104143925.194295-1-alexis.lothore@bootlin.com> Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-GND-Sasl: alexis.lothore@bootlin.com From: Alexis Lothoré With lockdep enabled, calls to the connect function from cfg802.11 layer lead to the following warning: ============================= WARNING: suspicious RCU usage 6.7.0-rc1-wt+ #333 Not tainted ----------------------------- drivers/net/wireless/microchip/wilc1000/hif.c:386 suspicious rcu_dereference_check() usage! [...] stack backtrace: CPU: 0 PID: 100 Comm: wpa_supplicant Not tainted 6.7.0-rc1-wt+ #333 Hardware name: Atmel SAMA5 unwind_backtrace from show_stack+0x18/0x1c show_stack from dump_stack_lvl+0x34/0x48 dump_stack_lvl from wilc_parse_join_bss_param+0x7dc/0x7f4 wilc_parse_join_bss_param from connect+0x2c4/0x648 connect from cfg80211_connect+0x30c/0xb74 cfg80211_connect from nl80211_connect+0x860/0xa94 nl80211_connect from genl_rcv_msg+0x3fc/0x59c genl_rcv_msg from netlink_rcv_skb+0xd0/0x1f8 netlink_rcv_skb from genl_rcv+0x2c/0x3c genl_rcv from netlink_unicast+0x3b0/0x550 netlink_unicast from netlink_sendmsg+0x368/0x688 netlink_sendmsg from ____sys_sendmsg+0x190/0x430 ____sys_sendmsg from ___sys_sendmsg+0x110/0x158 ___sys_sendmsg from sys_sendmsg+0xe8/0x150 sys_sendmsg from ret_fast_syscall+0x0/0x1c This warning is emitted because in the connect path, when trying to parse target BSS parameters, we dereference a RCU pointer whithout being in RCU critical section. Fix RCU dereference usage by moving it to a RCU read critical section. To avoid wrapping the whole wilc_parse_join_bss_param under the critical section, just use the critical section to copy ies data Fixes: c460495ee072 ("staging: wilc1000: fix incorrent type in initializer") Signed-off-by: Alexis Lothoré --- drivers/net/wireless/microchip/wilc1000/hif.c | 35 ++++++++++++------- 1 file changed, 23 insertions(+), 12 deletions(-) diff --git a/drivers/net/wireless/microchip/wilc1000/hif.c b/drivers/net/wireless/microchip/wilc1000/hif.c index 6f1218a51061..806b7337b5ae 100644 --- a/drivers/net/wireless/microchip/wilc1000/hif.c +++ b/drivers/net/wireless/microchip/wilc1000/hif.c @@ -377,38 +377,48 @@ struct wilc_join_bss_param * wilc_parse_join_bss_param(struct cfg80211_bss *bss, struct cfg80211_crypto_settings *crypto) { - const struct cfg80211_bss_ies *ies = rcu_dereference(bss->ies); - const u8 *tim_elm, *ssid_elm, *rates_ie, *supp_rates_ie; + const u8 *ies_data, *tim_elm, *ssid_elm, *rates_ie, *supp_rates_ie; const u8 *ht_ie, *wpa_ie, *wmm_ie, *rsn_ie; struct ieee80211_p2p_noa_attr noa_attr; + const struct cfg80211_bss_ies *ies; struct wilc_join_bss_param *param; - u8 rates_len = 0; + u8 rates_len = 0, ies_len; int ret; param = kzalloc(sizeof(*param), GFP_KERNEL); if (!param) return NULL; + rcu_read_lock(); + ies = rcu_dereference(bss->ies); + ies_data = kmemdup(ies->data, ies->len, GFP_ATOMIC); + if (!ies_data) { + rcu_read_unlock(); + return NULL; + } + ies_len = ies->len; + rcu_read_unlock(); + param->beacon_period = cpu_to_le16(bss->beacon_interval); param->cap_info = cpu_to_le16(bss->capability); param->bss_type = WILC_FW_BSS_TYPE_INFRA; param->ch = ieee80211_frequency_to_channel(bss->channel->center_freq); ether_addr_copy(param->bssid, bss->bssid); - ssid_elm = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); + ssid_elm = cfg80211_find_ie(WLAN_EID_SSID, ies_data, ies_len); if (ssid_elm) { if (ssid_elm[1] <= IEEE80211_MAX_SSID_LEN) memcpy(param->ssid, ssid_elm + 2, ssid_elm[1]); } - tim_elm = cfg80211_find_ie(WLAN_EID_TIM, ies->data, ies->len); + tim_elm = cfg80211_find_ie(WLAN_EID_TIM, ies_data, ies_len); if (tim_elm && tim_elm[1] >= 2) param->dtim_period = tim_elm[3]; memset(param->p_suites, 0xFF, 3); memset(param->akm_suites, 0xFF, 3); - rates_ie = cfg80211_find_ie(WLAN_EID_SUPP_RATES, ies->data, ies->len); + rates_ie = cfg80211_find_ie(WLAN_EID_SUPP_RATES, ies_data, ies_len); if (rates_ie) { rates_len = rates_ie[1]; if (rates_len > WILC_MAX_RATES_SUPPORTED) @@ -419,7 +429,7 @@ wilc_parse_join_bss_param(struct cfg80211_bss *bss, if (rates_len < WILC_MAX_RATES_SUPPORTED) { supp_rates_ie = cfg80211_find_ie(WLAN_EID_EXT_SUPP_RATES, - ies->data, ies->len); + ies_data, ies_len); if (supp_rates_ie) { u8 ext_rates = supp_rates_ie[1]; @@ -434,11 +444,11 @@ wilc_parse_join_bss_param(struct cfg80211_bss *bss, } } - ht_ie = cfg80211_find_ie(WLAN_EID_HT_CAPABILITY, ies->data, ies->len); + ht_ie = cfg80211_find_ie(WLAN_EID_HT_CAPABILITY, ies_data, ies_len); if (ht_ie) param->ht_capable = true; - ret = cfg80211_get_p2p_attr(ies->data, ies->len, + ret = cfg80211_get_p2p_attr(ies_data, ies_len, IEEE80211_P2P_ATTR_ABSENCE_NOTICE, (u8 *)&noa_attr, sizeof(noa_attr)); if (ret > 0) { @@ -462,7 +472,7 @@ wilc_parse_join_bss_param(struct cfg80211_bss *bss, } wmm_ie = cfg80211_find_vendor_ie(WLAN_OUI_MICROSOFT, WLAN_OUI_TYPE_MICROSOFT_WMM, - ies->data, ies->len); + ies_data, ies_len); if (wmm_ie) { struct ieee80211_wmm_param_ie *ie; @@ -477,13 +487,13 @@ wilc_parse_join_bss_param(struct cfg80211_bss *bss, wpa_ie = cfg80211_find_vendor_ie(WLAN_OUI_MICROSOFT, WLAN_OUI_TYPE_MICROSOFT_WPA, - ies->data, ies->len); + ies_data, ies_len); if (wpa_ie) { param->mode_802_11i = 1; param->rsn_found = true; } - rsn_ie = cfg80211_find_ie(WLAN_EID_RSN, ies->data, ies->len); + rsn_ie = cfg80211_find_ie(WLAN_EID_RSN, ies_data, ies_len); if (rsn_ie) { int rsn_ie_len = sizeof(struct element) + rsn_ie[1]; int offset = 8; @@ -517,6 +527,7 @@ wilc_parse_join_bss_param(struct cfg80211_bss *bss, param->akm_suites[i] = crypto->akm_suites[i] & 0xFF; } + kfree(ies_data); return (void *)param; }