From nobody Mon Sep 29 21:14:54 2025 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 B2469C00140 for ; Mon, 15 Aug 2022 21:49:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349966AbiHOVtW (ORCPT ); Mon, 15 Aug 2022 17:49:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59122 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349914AbiHOVqx (ORCPT ); Mon, 15 Aug 2022 17:46:53 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2DAFEF5A8; Mon, 15 Aug 2022 12:30:29 -0700 (PDT) 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 0D4C0B81062; Mon, 15 Aug 2022 19:30:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA951C433D6; Mon, 15 Aug 2022 19:30:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660591826; bh=gqZqvMMoU9PCHolnyKg7cH/DHSogTy0MjLC2kf95GtU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qda69yediEgylxatPe0oZJ6lvxco/0Hmn+kNOKJ7BAYqxRGPlHDpIgwQZRjRQo4V2 LY+e6WRH3y7Ej6j1OI6BbPMf0YxESOYJOMzaQ4CTywToPi92fetLqJNjzFHDH963ZJ 49gKolIEkfupJp8BhbVBFLviPoq4F+Oti9HKjUZA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeongik Cha , Johannes Berg Subject: [PATCH 5.19 0014/1157] wifi: mac80211_hwsim: fix race condition in pending packet Date: Mon, 15 Aug 2022 19:49:30 +0200 Message-Id: <20220815180440.034984794@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180439.416659447@linuxfoundation.org> References: <20220815180439.416659447@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Jeongik Cha commit 4ee186fa7e40ae06ebbfbad77e249e3746e14114 upstream. A pending packet uses a cookie as an unique key, but it can be duplicated because it didn't use atomic operators. And also, a pending packet can be null in hwsim_tx_info_frame_received_nl due to race condition with mac80211_hwsim_stop. For this, * Use an atomic type and operator for a cookie * Add a lock around the loop for pending packets Signed-off-by: Jeongik Cha Link: https://lore.kernel.org/r/20220704084354.3556326-1-jeongik@google.com Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/mac80211_hwsim.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -680,7 +680,7 @@ struct mac80211_hwsim_data { bool ps_poll_pending; struct dentry *debugfs; =20 - uintptr_t pending_cookie; + atomic64_t pending_cookie; struct sk_buff_head pending; /* packets pending */ /* * Only radios in the same group can communicate together (the @@ -1347,7 +1347,7 @@ static void mac80211_hwsim_tx_frame_nl(s int i; struct hwsim_tx_rate tx_attempts[IEEE80211_TX_MAX_RATES]; struct hwsim_tx_rate_flag tx_attempts_flags[IEEE80211_TX_MAX_RATES]; - uintptr_t cookie; + u64 cookie; =20 if (data->ps !=3D PS_DISABLED) hdr->frame_control |=3D cpu_to_le16(IEEE80211_FCTL_PM); @@ -1416,8 +1416,7 @@ static void mac80211_hwsim_tx_frame_nl(s goto nla_put_failure; =20 /* We create a cookie to identify this skb */ - data->pending_cookie++; - cookie =3D data->pending_cookie; + cookie =3D (u64)atomic64_inc_return(&data->pending_cookie); info->rate_driver_data[0] =3D (void *)cookie; if (nla_put_u64_64bit(skb, HWSIM_ATTR_COOKIE, cookie, HWSIM_ATTR_PAD)) goto nla_put_failure; @@ -4080,6 +4079,7 @@ static int hwsim_tx_info_frame_received_ const u8 *src; unsigned int hwsim_flags; int i; + unsigned long flags; bool found =3D false; =20 if (!info->attrs[HWSIM_ATTR_ADDR_TRANSMITTER] || @@ -4107,18 +4107,20 @@ static int hwsim_tx_info_frame_received_ } =20 /* look for the skb matching the cookie passed back from user */ + spin_lock_irqsave(&data2->pending.lock, flags); skb_queue_walk_safe(&data2->pending, skb, tmp) { u64 skb_cookie; =20 txi =3D IEEE80211_SKB_CB(skb); - skb_cookie =3D (u64)(uintptr_t)txi->rate_driver_data[0]; + skb_cookie =3D (u64)txi->rate_driver_data[0]; =20 if (skb_cookie =3D=3D ret_skb_cookie) { - skb_unlink(skb, &data2->pending); + __skb_unlink(skb, &data2->pending); found =3D true; break; } } + spin_unlock_irqrestore(&data2->pending.lock, flags); =20 /* not found */ if (!found)