From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2424BC433B4 for ; Mon, 5 Apr 2021 15:34:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F157E60FEF for ; Mon, 5 Apr 2021 15:34:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238395AbhDEPfB (ORCPT ); Mon, 5 Apr 2021 11:35:01 -0400 Received: from jabberwock.ucw.cz ([46.255.230.98]:47818 "EHLO jabberwock.ucw.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238291AbhDEPfA (ORCPT ); Mon, 5 Apr 2021 11:35:00 -0400 Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 2AFE51C0B7D; Mon, 5 Apr 2021 17:34:53 +0200 (CEST) Date: Mon, 5 Apr 2021 17:34:52 +0200 From: Pavel Machek To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Shuah Khan , Kalle Valo , Sasha Levin Subject: Re: [PATCH 5.10 047/126] ath10k: hold RCU lock when calling ieee80211_find_sta_by_ifaddr() Message-ID: <20210405153452.GC32232@amd> References: <20210405085031.040238881@linuxfoundation.org> <20210405085032.596054465@linuxfoundation.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="9Ek0hoCL9XbhcSqy" Content-Disposition: inline In-Reply-To: <20210405085032.596054465@linuxfoundation.org> User-Agent: Mutt/1.5.23 (2014-03-12) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --9Ek0hoCL9XbhcSqy Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > Fix ath10k_wmi_tlv_op_pull_peer_stats_info() to hold RCU lock before it > calls ieee80211_find_sta_by_ifaddr() and release it when the resulting > pointer is no longer needed. It does that. But is also does the unlock even if it did not take the lock: > +++ b/drivers/net/wireless/ath/ath10k/wmi-tlv.c > @@ -576,13 +576,13 @@ static void ath10k_wmi_event_tdls_peer(struct ath10= k *ar, struct sk_buff *skb) > case WMI_TDLS_TEARDOWN_REASON_TX: > case WMI_TDLS_TEARDOWN_REASON_RSSI: > case WMI_TDLS_TEARDOWN_REASON_PTR_TIMEOUT: > + rcu_read_lock(); > station =3D ieee80211_find_sta_by_ifaddr(ar->hw, > ev->peer_macaddr.addr, > NULL); > if (!station) { > ath10k_warn(ar, "did not find station from tdls peer event"); > - kfree(tb); > - return; > + goto exit; > } > arvif =3D ath10k_get_arvif(ar, __le32_to_cpu(ev->vdev_id)); > ieee80211_tdls_oper_request( > @@ -593,6 +593,9 @@ static void ath10k_wmi_event_tdls_peer(struct ath10k = *ar, struct sk_buff *skb) > ); > break; > } > + > +exit: > + rcu_read_unlock(); > kfree(tb); > } The switch only takes the lock in 3 branches, but it is released unconditionally at the end. Something like this? Best regards, Pavel Signed-off-by: Pavel Machek (CIP) diff --git a/drivers/net/wireless/ath/ath10k/wmi-tlv.c b/drivers/net/wirele= ss/ath/ath10k/wmi-tlv.c index e7072fc4f487..e03ff56d938b 100644 --- a/drivers/net/wireless/ath/ath10k/wmi-tlv.c +++ b/drivers/net/wireless/ath/ath10k/wmi-tlv.c @@ -582,20 +582,19 @@ static void ath10k_wmi_event_tdls_peer(struct ath10k = *ar, struct sk_buff *skb) NULL); if (!station) { ath10k_warn(ar, "did not find station from tdls peer event"); - goto exit; - } - arvif =3D ath10k_get_arvif(ar, __le32_to_cpu(ev->vdev_id)); - ieee80211_tdls_oper_request( + } else { + arvif =3D ath10k_get_arvif(ar, __le32_to_cpu(ev->vdev_id)); + ieee80211_tdls_oper_request( arvif->vif, station->addr, NL80211_TDLS_TEARDOWN, WLAN_REASON_TDLS_TEARDOWN_UNREACHABLE, GFP_ATOMIC ); + } + rcu_read_unlock(); break; } =20 -exit: - rcu_read_unlock(); kfree(tb); } =20 --=20 http://www.livejournal.com/~pavelmachek --9Ek0hoCL9XbhcSqy Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAmBrLhwACgkQMOfwapXb+vKkJACfX2IZWhZgB25cUE0Z9ij0EH75 eOAAnAnqYgGWEgn9M4c0O1zko9JRR4DE =QVpV -----END PGP SIGNATURE----- --9Ek0hoCL9XbhcSqy--