From patchwork Mon Feb 27 11:07:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Felix Fietkau X-Patchwork-Id: 657454 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 289B1C7EE2D for ; Mon, 27 Feb 2023 11:07:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229632AbjB0LHr (ORCPT ); Mon, 27 Feb 2023 06:07:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42228 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229568AbjB0LHp (ORCPT ); Mon, 27 Feb 2023 06:07:45 -0500 Received: from nbd.name (nbd.name [46.4.11.11]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDEB5199DC for ; Mon, 27 Feb 2023 03:07:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=nbd.name; s=20160729; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=hUywMLHsKjNf1A61SwfkHT4XqRFx8ehX6xLPAfyruyA=; b=Y1DqPxaw7eimm6iCDYelZy3sQl GxyuT8tsLuBpFmoyPpkZ/3Xgy0uj7SfCxXO6fZlysIaIa3ERVD4rPQ/8e828jcWprax28MDD2n8S4 w4qn/ZdJ+a+5DnSLZoZCYdoI994NRkcCH5hZs6jB2U8T4vdN6J5ca0c/6DE7dVRAbLcU=; Received: from p54ae9730.dip0.t-ipconnect.de ([84.174.151.48] helo=Maecks.lan) by ds12 with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (Exim 4.94.2) (envelope-from ) id 1pWbM5-00CVRm-Jy; Mon, 27 Feb 2023 12:07:41 +0100 From: Felix Fietkau To: linux-wireless@vger.kernel.org Cc: johannes@sipsolutions.net Subject: [RFC 2/5] wifi: mac80211: fix race in mesh sequence number assignment Date: Mon, 27 Feb 2023 12:07:35 +0100 Message-Id: <20230227110738.54241-2-nbd@nbd.name> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230227110738.54241-1-nbd@nbd.name> References: <20230227110738.54241-1-nbd@nbd.name> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Since the sequence number is shared across different tx queues, it needs to be atomic in order to avoid accidental duplicate assignment Signed-off-by: Felix Fietkau --- net/mac80211/ieee80211_i.h | 2 +- net/mac80211/mesh.c | 6 ++---- 2 files changed, 3 insertions(+), 5 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index ecc232eb1ee8..9df5e74efb42 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -696,7 +696,7 @@ struct ieee80211_if_mesh { struct mesh_stats mshstats; struct mesh_config mshcfg; atomic_t estab_plinks; - u32 mesh_seqnum; + atomic_t mesh_seqnum; bool accepting_plinks; int num_gates; struct beacon_data __rcu *beacon; diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c index 5a99b8f6e465..0608ed415831 100644 --- a/net/mac80211/mesh.c +++ b/net/mac80211/mesh.c @@ -752,10 +752,8 @@ unsigned int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata, meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL; - /* FIXME: racy -- TX on multiple queues can be concurrent */ - put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum); - sdata->u.mesh.mesh_seqnum++; - + put_unaligned_le32(atomic_inc_return(&sdata->u.mesh.mesh_seqnum), + &meshhdr->seqnum); if (addr4or5 && !addr6) { meshhdr->flags |= MESH_FLAGS_AE_A4; memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);