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 73F2037D111 for ; Tue, 24 Feb 2026 12:33:49 +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=1771936430; cv=none; b=ja9atEkUGp6qDlHPJDjiG1en92iaNEM5QAQX+2xKqOehu9VxOSsFAk+qy9WpYAqfLgzdAHVR+bmKOkic8SwQ0VrVltYhJS3GQAJvJRWV+X9m2SpXhU8VOwJ1LhYNj2Qv6DqzmxpGBhx/0kRTa59Z9Hp1JU3g3azo94VQe9B3c1s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771936430; c=relaxed/simple; bh=clZnONM24nEys84smKGnPS40DZNnvZ0axgHZ537gWa8=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=lrQBr5as2VMkC4dEEaE8dznXjDv83X36WaleWoXY9JeEJ+cAJZs89CXcPEa9TOWYszdxpn7XGXDR9kEbRn3PecztSuRZcgH2NqPP2CDYKtlYtjepLV3T6tONhF9PAkkmiw31uk1VYdcvNxnxpDFsXcNcG6kOlG+F8lcx/RqaO0w= 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=DRfJcHyZ; 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="DRfJcHyZ" Received: by mail-qv1-f74.google.com with SMTP id 6a1803df08f44-8950562d351so85191886d6.3 for ; Tue, 24 Feb 2026 04:33:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1771936428; x=1772541228; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=fQbu6Cl/paq0E3UGNbm7xLXUbURoFHMRf6FXvlp9cXk=; b=DRfJcHyZo/thIw0B82gbRNF0xsmJbkZsu+3/nqihuaJMlQaTepzOdb2cibeNP3/hi4 qyA2u0XRgeuaNgnPB75K0ZrC7FFudSDP0XZPgx+e8p60RSddUXYai81xEG28HSz1rto5 k+hBVIKjlAAxFl9ljvIK8bvRNM736Fxxdx2QAf4JpEp9wm0pOFMgGwAKNZWJ/MSDGMsq oSmgGWRDf2jklSm95lgjl7fZ2r+SitFxB1MazUFFbo1ZJVvGxumtHdqtbgIG458PotII FT7Q4hBTegrALhUy8KFll0N8b3WpmKKWtpTGQsISYzUrGzhh92zwqJ/SguHHNUgjIk7q bCGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771936428; x=1772541228; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=fQbu6Cl/paq0E3UGNbm7xLXUbURoFHMRf6FXvlp9cXk=; b=nUtQhYoCg1TwkvsMn6qacFEmnDj064DAPqTkp7DthcRIhtfX2p9rrrlYwa+S0l7Q7Q bSVu8rr9Uv76/Ne1rR28hUwgabUk+E5vLh+/xcLveOohuBCMmgowTdZtGt8OWX2YwpEV 6y0YdMn67APnsdJEjYv9SGy0fX0BodfLYSep6PDMjHVatXngLJYaVCTuf5AQH5+daKfL NTNKbmdh6739/BG1zyJsqxIqtk7KNd78cNDSNnShXJ51dlMdtAwjTu9UM9YmfBI7hfWc MpbsTcC+0Teuk6Y4kmYBv3Hu2ct8eAuLJjMwcBkgj484lj+f9tEuSx19jFcWPUze0CKk ad0A== X-Gm-Message-State: AOJu0YxCn68TOlF1rn7y4rm/aoGGBFjlaQQ/xnnEQJP7zZSKX1wV9B50 SPg0bbLGctdlc2aS0fO7RjWv8Wq3jnnCWsdQ9AYYDxiS6oK4kxBiEOXv11nN0jGy1+9gi83kXao agU/AotOfkP1/eQ== X-Received: from qvbif8.prod.google.com ([2002:a05:6214:1c48:b0:894:2b9f:cc7e]) (user=edumazet job=prod-delivery.src-stubby-dispatcher) by 2002:ad4:5c8c:0:b0:880:498e:a63e with SMTP id 6a1803df08f44-89979c53d67mr180727396d6.2.1771936428183; Tue, 24 Feb 2026 04:33:48 -0800 (PST) Date: Tue, 24 Feb 2026 12:33:47 +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: <20260224123347.3163030-1-edumazet@google.com> Subject: [PATCH nf-next] netfilter: nf_log_syslog: no longer acquire sk_callback_lock in nf_log_dump_sk_uid_gid() From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni , Pablo Neira Ayuso , Florian Westphal 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 nf_log_dump_sk_uid_gid() to avoid touching sk_callback_lock. Signed-off-by: Eric Dumazet --- net/netfilter/nf_log_syslog.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nf_log_syslog.c b/net/netfilter/nf_log_syslog.c index 41503847d9d7fb21824fabb1b57b45f2622b9310..dee6be17440c6c0f202fc2ba67129437879e45a6 100644 --- a/net/netfilter/nf_log_syslog.c +++ b/net/netfilter/nf_log_syslog.c @@ -165,18 +165,28 @@ static struct nf_logger nf_arp_logger __read_mostly = { static void nf_log_dump_sk_uid_gid(struct net *net, struct nf_log_buf *m, struct sock *sk) { + const struct socket *sock; + const struct file *file; + if (!sk || !sk_fullsock(sk) || !net_eq(net, sock_net(sk))) return; - read_lock_bh(&sk->sk_callback_lock); - if (sk->sk_socket && sk->sk_socket->file) { - const struct cred *cred = sk->sk_socket->file->f_cred; + /* 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); + file = sock ? READ_ONCE(sock->file) : NULL; + if (file) { + const struct cred *cred = file->f_cred; nf_log_buf_add(m, "UID=%u GID=%u ", from_kuid_munged(&init_user_ns, cred->fsuid), from_kgid_munged(&init_user_ns, cred->fsgid)); } - read_unlock_bh(&sk->sk_callback_lock); + rcu_read_unlock(); } static noinline_for_stack int -- 2.53.0.371.g1d285c8824-goog