From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [91.216.245.30]) (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 CF7E93914E5; Wed, 4 Mar 2026 11:50:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.216.245.30 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772625003; cv=none; b=L0gt3sqsR/DMkmu1HxRyc7PoL0mnIA+B+H0nEjpiE9zmA6J+ib1FEsAhlwekBwB5c3lMWI45Vt0vixYyfBznq8vZsd9hPVB4ED0l50OBGHHOkFMHKuDkCATHwvYNIoNbeJf5dlqCLgoyRU7Z72RqzfyC9fWigJYTyNLt5Xvvh2c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772625003; c=relaxed/simple; bh=4pe+sHODYeIYo88bnHLEvrJ7GGhn9cC/0AOnuI6XwP0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JtmfjL4KMwyD2xxWqqU117Yl+anPGbVdwoGOAsIqiWIlusT5buOahUtwU1rM6BKEladO35doJA/SJ2YM2BYJaqIPm56LDg+DHq9/d3EDlsXAEpXiMkv24p4G4ph18bgSE2lZP/gEutn+W+Pl7fVcfJ/Yn98F1EhB8Hmj5Qvy0Jo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de; spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc; arc=none smtp.client-ip=91.216.245.30 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc Received: by Chamillionaire.breakpoint.cc (Postfix, from userid 1003) id 7BFBF6026E; Wed, 04 Mar 2026 12:50:00 +0100 (CET) From: Florian Westphal To: Cc: Paolo Abeni , "David S. Miller" , Eric Dumazet , Jakub Kicinski , , pablo@netfilter.org Subject: [PATCH net-next 07/14] netfilter: nfnetlink_log: no longer acquire sk_callback_lock Date: Wed, 4 Mar 2026 12:49:14 +0100 Message-ID: <20260304114921.31042-8-fw@strlen.de> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260304114921.31042-1-fw@strlen.de> References: <20260304114921.31042-1-fw@strlen.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Eric Dumazet After commit 983512f3a87f ("net: Drop the lock in skb_may_tx_timestamp()") from Sebastian Andrzej Siewior, apply the same logic in __build_packet_message() to avoid touching sk->sk_callback_lock. Signed-off-by: Eric Dumazet Signed-off-by: Florian Westphal --- net/netfilter/nfnetlink_log.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index b35a90955e2e..730c2541a849 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -611,19 +611,26 @@ __build_packet_message(struct nfnl_log_net *log, /* UID */ sk = skb->sk; if (sk && sk_fullsock(sk)) { - read_lock_bh(&sk->sk_callback_lock); - if (sk->sk_socket && sk->sk_socket->file) { - struct file *file = sk->sk_socket->file; + const struct socket *sock; + const struct file *file; + + /* 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. + */ + sock = READ_ONCE(sk->sk_socket); + file = sock ? READ_ONCE(sock->file) : NULL; + if (file) { const struct cred *cred = file->f_cred; struct user_namespace *user_ns = inst->peer_user_ns; __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid)); __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid)); - read_unlock_bh(&sk->sk_callback_lock); if (nla_put_be32(inst->skb, NFULA_UID, uid) || nla_put_be32(inst->skb, NFULA_GID, gid)) goto nla_put_failure; - } else - read_unlock_bh(&sk->sk_callback_lock); + } } /* local sequence number */ -- 2.52.0