From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qv1-f74.google.com (mail-qv1-f74.google.com [209.85.219.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 53AB6396D0F for ; Tue, 24 Feb 2026 12:29:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771936141; cv=none; b=X0yH6gVbau1tzvU1pgkW8qWT74piQZTr1f++LfMI7K1d12eTPCK6l8f5nhGJc3CKt3c8In1J0HoFtPOAqLp/v5DAuMej4k2+v4WqIFQ/Imqt8koOKCxkcKJUOwlwR1NMjXhG3oPtPDAlsERCkkLsVrY3cHGVNEi/lSETd7vZwCY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771936141; c=relaxed/simple; bh=Hsp3tQRgE2zFNjV/zPyI9+zpkx3vWREcoZDnXwGASz4=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=RW4Rs7WAXtrrIocKhL0l6r8x0TTQLbUlUKA+h6kD/SqV2x8GMshMrg0C9A08PTpJuzH8iWDYXX/HfzEo2bpqu2kH2O6gxk0ZkTWONhXld7TDT+av9cByQBYAVj9ewHNuIW72uvcI3Voc9COkEbHcbRSpGBfBr4bKmFfec1iD4xU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=pQF8ulBj; arc=none smtp.client-ip=209.85.219.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="pQF8ulBj" Received: by mail-qv1-f74.google.com with SMTP id 6a1803df08f44-899b12d76adso5806166d6.2 for ; Tue, 24 Feb 2026 04:29:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1771936139; x=1772540939; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=a3rCfk+n+zciKXPjSKsHFA//hqZJBADhsDjD5jNhlu0=; b=pQF8ulBjgHi6Qwhdh7vHAV1pUExFxKgs4FchQvk91eIGbSOyhJeeWwTvoqet9tTkhY 5wxuF98tQouSTrg5bxK1XHerVSLOgZK4DGHLsBUobXjiT/zY3yISiSKlm/vpKJv34lLn rBQPeCWG8FKi1nnQ+VppHDECOGFrIo/tLaVPOSv5iQoMJL6byJRpJksEtfHauWyeO+89 nFwnX50s8NzBvbAgVnToCBeFIDv7rsLOgfb9dnJcVNdleu6BTv+w2k9fkTLjmoD+1vL1 puI3/uBStM3ZYOEc47WiPgnW3FaPJWlYuLy+YwI5jyLyaR3oGiuCjQIl3AYaFBElIhuY Scng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771936139; x=1772540939; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=a3rCfk+n+zciKXPjSKsHFA//hqZJBADhsDjD5jNhlu0=; b=vzkDgkYfxHzdWbPa+YszP/mcZRlkFhzb0/DM5KnKYaUO5mCLzgARhK1aVNHSWpzNsz xFyTXccvs86Nd4PLFWvQ6XQJwbom3XhZTsmJT5O1iSMknaxCENutCADj9T94ms9oNpUB qhqWPnnV0ZrHiAy685G42zloVR5mVYY49zFYSnjAfc3HHkUCoR/VfMhpg9r5O/Wpcvtm 48OdmwPZklQt5miOHjFvxW2tq4MlIJFkBYvBtzdK0lc9jhztNYoLfgxgQgHtcSf5frTV nF0dMy10hHMqLURv1m8lz5npycMQ/sXWelWaG7zRPOrYELCL5Rw3oJk/qV5zAONm/igw GEaA== X-Gm-Message-State: AOJu0YzTfePvGmDIQPNKFJnc6f19PwxcXfUIawDDdHfvgy/nZ5NzUmwo Jykv4wdkw8Ozj0Iqebo3uEammMCChdnDsWotz/eYkbhC5iYswovMx1EARE3V9Xlu/KPU7Khe18B KOFq32bG1+2/xvA== X-Received: from qvbqo13.prod.google.com ([2002:a05:6214:590d:b0:894:946e:3688]) (user=edumazet job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6214:5646:b0:899:b004:13c with SMTP id 6a1803df08f44-899b00402f3mr4162046d6.17.1771936139013; Tue, 24 Feb 2026 04:28:59 -0800 (PST) Date: Tue, 24 Feb 2026 12:28:56 +0000 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.53.0.371.g1d285c8824-goog Message-ID: <20260224122856.3152608-1-edumazet@google.com> Subject: [PATCH net-next] netfilter: xt_owner: no longer acquire sk_callback_lock in mt_owner() From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni , Pablo Neira Ayuso , Florian Westphal , Jozsef Kadlecsik Cc: netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, eric.dumazet@gmail.com, Eric Dumazet Content-Type: text/plain; charset="UTF-8" After commit 983512f3a87f ("net: Drop the lock in skb_may_tx_timestamp()") from Sebastian Andrzej Siewior, apply the same logic in mt_owner() to avoid touching sk_callback_lock. Signed-off-by: Eric Dumazet --- net/netfilter/xt_owner.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/net/netfilter/xt_owner.c b/net/netfilter/xt_owner.c index 50332888c8d233aab0915a31f2f616f3171da45e..5845eabe6161b3a90df422e6e1055165d6538791 100644 --- a/net/netfilter/xt_owner.c +++ b/net/netfilter/xt_owner.c @@ -63,11 +63,12 @@ static bool owner_mt(const struct sk_buff *skb, struct xt_action_param *par) { const struct xt_owner_match_info *info = par->matchinfo; - const struct file *filp; struct sock *sk = skb_to_full_sk(skb); struct net *net = xt_net(par); + const struct socket *sock; + const struct file *filp; - if (!sk || !sk->sk_socket || !net_eq(net, sock_net(sk))) + if (!sk || !READ_ONCE(sk->sk_socket) || !net_eq(net, sock_net(sk))) return (info->match ^ info->invert) == 0; else if (info->match & info->invert & XT_OWNER_SOCKET) /* @@ -76,10 +77,16 @@ owner_mt(const struct sk_buff *skb, struct xt_action_param *par) */ return false; - read_lock_bh(&sk->sk_callback_lock); - filp = sk->sk_socket ? sk->sk_socket->file : NULL; + /* The sk pointer remains valid as long as the skb is. The sk_socket and + * file pointer may become NULL if the socket is closed. Both structures + * (including file->cred) are RCU freed which means they can be accessed + * within a RCU read section. + */ + rcu_read_lock(); + sock = READ_ONCE(sk->sk_socket); + filp = sock ? READ_ONCE(sock->file) : NULL; if (filp == NULL) { - read_unlock_bh(&sk->sk_callback_lock); + rcu_read_unlock(); return ((info->match ^ info->invert) & (XT_OWNER_UID | XT_OWNER_GID)) == 0; } @@ -90,7 +97,7 @@ owner_mt(const struct sk_buff *skb, struct xt_action_param *par) if ((uid_gte(filp->f_cred->fsuid, uid_min) && uid_lte(filp->f_cred->fsuid, uid_max)) ^ !(info->invert & XT_OWNER_UID)) { - read_unlock_bh(&sk->sk_callback_lock); + rcu_read_unlock(); return false; } } @@ -118,12 +125,12 @@ owner_mt(const struct sk_buff *skb, struct xt_action_param *par) } if (match ^ !(info->invert & XT_OWNER_GID)) { - read_unlock_bh(&sk->sk_callback_lock); + rcu_read_unlock(); return false; } } - read_unlock_bh(&sk->sk_callback_lock); + rcu_read_unlock(); return true; } -- 2.53.0.371.g1d285c8824-goog