From nobody Fri Sep 5 20:20:13 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 A29F6C38145 for ; Tue, 23 Aug 2022 11:11:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357303AbiHWLKh (ORCPT ); Tue, 23 Aug 2022 07:10:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356880AbiHWLJ3 (ORCPT ); Tue, 23 Aug 2022 07:09:29 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE1C8B600B; Tue, 23 Aug 2022 02:16:34 -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 9B045B81C4E; Tue, 23 Aug 2022 09:16:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ECD62C433D6; Tue, 23 Aug 2022 09:16:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661246191; bh=mxc4FCwhh4wGcmTZOCCO3jATcl1N5iujFXPwPoxxkCM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OxVVLK0WIcmBcoaW+E1MbF27TSx6xhQvh7Cpg0SG/o1rXQlO2/GluOi8EvnFsdLQE Q75WCVmlqQOlnGN4jaoTj823LiJD5KQJhNYCoGPdEFbaOzIA5/+s9toUx+lVQ3otjH kZP7CbgSP1/9FaHdpsI2vlO04HHIqT7V5bgb1Vbk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeongik Cha , Johannes Berg Subject: [PATCH 5.4 006/389] wifi: mac80211_hwsim: fix race condition in pending packet Date: Tue, 23 Aug 2022 10:21:24 +0200 Message-Id: <20220823080115.906262705@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080115.331990024@linuxfoundation.org> References: <20220823080115.331990024@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 @@ -527,7 +527,7 @@ 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 @@ -1044,7 +1044,7 @@ 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); @@ -1113,8 +1113,7 @@ 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; @@ -3260,6 +3259,7 @@ 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] || @@ -3284,18 +3284,20 @@ static int hwsim_tx_info_frame_received_ goto out; =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)