From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D45643812F7; Sat, 12 Sep 2026 19:15:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789240540; cv=none; b=c2T9CtgNchXV4Em+KabTHdMWx0gP3DAqXf2w3QyUkyovgblN+aQFT0kj9gvOGCTJTqPF5JJdWOu7KQiiyMBmNqF6JRHfrns2J/E5OtEwI+CMKSiQx1YlwRnhDffHfml2+GKkKXRberKcS6cJ3hsbvKYCawJPz6fLafKOL8aVc+Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789240540; c=relaxed/simple; bh=ww0oLBVHVYY+7dxCCBYOVFLO1P75Z6dS2xvnRhN1hfk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=moA79q128v6fC+iYOf+l3EeVoHV2hc85DK9CQAdX26jaNlTUXyl90d5EN303jVfrVMVUYklLX5ZnHywDYZcJ2C0COy57ChbNTMuvkPviPIqrAmUJuKyQ/ZV6RFm3bka8aerV25h3yHcOlqV3898EQUwz0qW8XM/R+lw1d6XT6gM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=PSuQP5UZ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="PSuQP5UZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7CCA91F000FF; Sat, 12 Sep 2026 19:15:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789240538; bh=d/eJBZ2qjrRMWA4ETf71xDpxXMSprjyDTgRsCkWztEc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=PSuQP5UZBReyD+HuW2UYIbFaRpz++ACxONqzgJKF8oICruk5BPUHnS/wWsGzy8KGH pepqLmv3wnSc4MYw7xlu6KpnEwLuUYAKBWTGApLMzsUKD9RgVO/+2bdBcx/3yHOQjW RK/aT7aZzYcnbhigRuhM/vp7GW+wguzRtyrzImPw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Simon Horman , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 888/935] net_sched: act_skbmod: use RCU in tcf_skbmod_dump() Date: Sat, 12 Sep 2026 09:05:18 +0200 Message-ID: <20260912065547.180810648@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065526.833703348@linuxfoundation.org> References: <20260912065526.833703348@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 53df77e7859042a92914d664c860f65d9689f88d ] Also storing tcf_action into struct tcf_skbmod_params makes sure there is no discrepancy in tcf_skbmod_act(). No longer block BH in tcf_skbmod_init() when acquiring tcf_lock. Signed-off-by: Eric Dumazet Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250827125349.3505302-5-edumazet@google.com Signed-off-by: Jakub Kicinski Stable-dep-of: 81d0d1e64f30 ("net/sched: act_skbmod: fix length calculations and avoid invalid header warnings") Signed-off-by: Sasha Levin --- include/net/tc_act/tc_skbmod.h | 1 + net/sched/act_skbmod.c | 26 ++++++++++++-------------- 2 files changed, 13 insertions(+), 14 deletions(-) diff --git a/include/net/tc_act/tc_skbmod.h b/include/net/tc_act/tc_skbmod.h index 7c240d2fed4e3..626704cd6241b 100644 --- a/include/net/tc_act/tc_skbmod.h +++ b/include/net/tc_act/tc_skbmod.h @@ -12,6 +12,7 @@ struct tcf_skbmod_params { struct rcu_head rcu; u64 flags; /*up to 64 types of operations; extend if needed */ + int action; u8 eth_dst[ETH_ALEN]; u16 eth_type; u8 eth_src[ETH_ALEN]; diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c index 37395ab1df472..4507a53cefd34 100644 --- a/net/sched/act_skbmod.c +++ b/net/sched/act_skbmod.c @@ -25,19 +25,18 @@ static int tcf_skbmod_act(struct sk_buff *skb, const struct tc_action *a, struct tcf_result *res) { struct tcf_skbmod *d = to_skbmod(a); - int action, max_edit_len, err; struct tcf_skbmod_params *p; + int max_edit_len, err; u64 flags; tcf_lastuse_update(&d->tcf_tm); bstats_cpu_update(this_cpu_ptr(d->common.cpu_bstats), skb); - action = READ_ONCE(d->tcf_action); - if (unlikely(action == TC_ACT_SHOT)) + p = rcu_dereference_bh(d->skbmod_p); + if (unlikely(p->action == TC_ACT_SHOT)) goto drop; max_edit_len = skb_mac_header_len(skb); - p = rcu_dereference_bh(d->skbmod_p); flags = p->flags; /* tcf_skbmod_init() guarantees "flags" to be one of the following: @@ -83,7 +82,7 @@ static int tcf_skbmod_act(struct sk_buff *skb, const struct tc_action *a, INET_ECN_set_ce(skb); out: - return action; + return p->action; drop: qstats_overlimit_inc(this_cpu_ptr(d->common.cpu_qstats)); @@ -191,9 +190,9 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla, } p->flags = lflags; - + p->action = parm->action; if (ovr) - spin_lock_bh(&d->tcf_lock); + spin_lock(&d->tcf_lock); /* Protected by tcf_lock if overwriting existing action. */ goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); p_old = rcu_dereference_protected(d->skbmod_p, 1); @@ -207,7 +206,7 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla, rcu_assign_pointer(d->skbmod_p, p); if (ovr) - spin_unlock_bh(&d->tcf_lock); + spin_unlock(&d->tcf_lock); if (p_old) kfree_rcu(p_old, rcu); @@ -246,10 +245,9 @@ static int tcf_skbmod_dump(struct sk_buff *skb, struct tc_action *a, opt.index = d->tcf_index; opt.refcnt = refcount_read(&d->tcf_refcnt) - ref, opt.bindcnt = atomic_read(&d->tcf_bindcnt) - bind; - spin_lock_bh(&d->tcf_lock); - opt.action = d->tcf_action; - p = rcu_dereference_protected(d->skbmod_p, - lockdep_is_held(&d->tcf_lock)); + rcu_read_lock(); + p = rcu_dereference(d->skbmod_p); + opt.action = p->action; opt.flags = p->flags; if (nla_put(skb, TCA_SKBMOD_PARMS, sizeof(opt), &opt)) goto nla_put_failure; @@ -267,10 +265,10 @@ static int tcf_skbmod_dump(struct sk_buff *skb, struct tc_action *a, if (nla_put_64bit(skb, TCA_SKBMOD_TM, sizeof(t), &t, TCA_SKBMOD_PAD)) goto nla_put_failure; - spin_unlock_bh(&d->tcf_lock); + rcu_read_unlock(); return skb->len; nla_put_failure: - spin_unlock_bh(&d->tcf_lock); + rcu_read_unlock(); nlmsg_trim(skb, b); return -1; } -- 2.53.0