From patchwork Fri May 15 07:59:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Pali_Roh=C3=A1r?= X-Patchwork-Id: 11550701 X-Patchwork-Delegate: kvalo@adurom.com Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E2B05739 for ; Fri, 15 May 2020 08:00:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB62F206B6 for ; Fri, 15 May 2020 08:00:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589529623; bh=Lrg29hVRGlCPrHHmbYcVcsFCxxxwqFtQRLOD6b5xnYo=; h=From:To:Cc:Subject:Date:List-ID:From; b=eI0A6+SxwIDJks2ilbWn2gyICgecGwWAPR8lfcEXy7KYlobub5Of647o1b9Lh+qsL Q8q92YvQzuOT5rUzvDPlRS5qyiLncXGlTok98HZ9kA2WsfVHAP8zmWZIPnGFcnYcmJ QxvirkNdPy1g5M1xERf56HldYea9Qy4U5wFJMISg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727792AbgEOIAU (ORCPT ); Fri, 15 May 2020 04:00:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:42428 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726671AbgEOIAT (ORCPT ); Fri, 15 May 2020 04:00:19 -0400 Received: from pali.im (pali.im [31.31.79.79]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B7429205CB; Fri, 15 May 2020 08:00:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589529618; bh=Lrg29hVRGlCPrHHmbYcVcsFCxxxwqFtQRLOD6b5xnYo=; h=From:To:Cc:Subject:Date:From; b=NVL1ClV+Sf8z/LLTyPfAPgLsrbfvrui0OPb0oiN0r2sFmT2HTGCY9ZL41659B+T+Z g1Mkjy4xPFqndZ2U7GrGhq1Y9IlERJv+KJC8Eq+sMIWnW5nMTdKiLGgIoke92hUkJJ MA7S8k5YVMBd7HLwxBJz/0zxW6YevjCAcu4te5Wk= Received: by pali.im (Postfix) id A01805F0; Fri, 15 May 2020 10:00:16 +0200 (CEST) From: =?utf-8?q?Pali_Roh=C3=A1r?= To: Amitkumar Karwar , Ganapathi Bhat , Xinming Hu , Kalle Valo , "David S. Miller" , Cathy Luo , Avinash Patil , =?utf-8?q?Marek_Beh=C3=BAn?= Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] mwifiex: Fix memory corruption in dump_station Date: Fri, 15 May 2020 09:59:24 +0200 Message-Id: <20200515075924.13841-1-pali@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org The mwifiex_cfg80211_dump_station() uses static variable for iterating over a linked list of all associated stations (when the driver is in UAP role). This has a race condition if .dump_station is called in parallel for multiple interfaces. This corruption can be triggered by registering multiple SSIDs and calling, in parallel for multiple interfaces iw dev station dump [16750.719775] Unable to handle kernel paging request at virtual address dead000000000110 ... [16750.899173] Call trace: [16750.901696] mwifiex_cfg80211_dump_station+0x94/0x100 [mwifiex] [16750.907824] nl80211_dump_station+0xbc/0x278 [cfg80211] [16750.913160] netlink_dump+0xe8/0x320 [16750.916827] netlink_recvmsg+0x1b4/0x338 [16750.920861] ____sys_recvmsg+0x7c/0x2b0 [16750.924801] ___sys_recvmsg+0x70/0x98 [16750.928564] __sys_recvmsg+0x58/0xa0 [16750.932238] __arm64_sys_recvmsg+0x28/0x30 [16750.936453] el0_svc_common.constprop.3+0x90/0x158 [16750.941378] do_el0_svc+0x74/0x90 [16750.944784] el0_sync_handler+0x12c/0x1a8 [16750.948903] el0_sync+0x114/0x140 [16750.952312] Code: f9400003 f907f423 eb02007f 54fffd60 (b9401060) [16750.958583] ---[ end trace c8ad181c2f4b8576 ]--- This patch drops the use of the static iterator, and instead every time the function is called iterates to the idx-th position of the linked-list. It would be better to convert the code not to use linked list for associated stations storage (since the chip has a limited number of associated stations anyway - it could just be an array). Such a change may be proposed in the future. In the meantime this patch can backported into stable kernels in this simple form. Fixes: 8baca1a34d4c ("mwifiex: dump station support in uap mode") Signed-off-by: Pali Rohár Acked-by: Ganapathi Bhat --- drivers/net/wireless/marvell/mwifiex/cfg80211.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/drivers/net/wireless/marvell/mwifiex/cfg80211.c b/drivers/net/wireless/marvell/mwifiex/cfg80211.c index 1566d2197906..12bfd653a405 100644 --- a/drivers/net/wireless/marvell/mwifiex/cfg80211.c +++ b/drivers/net/wireless/marvell/mwifiex/cfg80211.c @@ -1496,7 +1496,8 @@ mwifiex_cfg80211_dump_station(struct wiphy *wiphy, struct net_device *dev, int idx, u8 *mac, struct station_info *sinfo) { struct mwifiex_private *priv = mwifiex_netdev_get_priv(dev); - static struct mwifiex_sta_node *node; + struct mwifiex_sta_node *node; + int i; if ((GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA) && priv->media_connected && idx == 0) { @@ -1506,13 +1507,10 @@ mwifiex_cfg80211_dump_station(struct wiphy *wiphy, struct net_device *dev, mwifiex_send_cmd(priv, HOST_CMD_APCMD_STA_LIST, HostCmd_ACT_GEN_GET, 0, NULL, true); - if (node && (&node->list == &priv->sta_list)) { - node = NULL; - return -ENOENT; - } - - node = list_prepare_entry(node, &priv->sta_list, list); - list_for_each_entry_continue(node, &priv->sta_list, list) { + i = 0; + list_for_each_entry(node, &priv->sta_list, list) { + if (i++ != idx) + continue; ether_addr_copy(mac, node->mac_addr); return mwifiex_dump_station_info(priv, node, sinfo); }