From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-178.mta1.migadu.com (out-178.mta1.migadu.com [95.215.58.178]) (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 D9E773A8746 for ; Tue, 2 Jun 2026 07:14:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780384459; cv=none; b=f4nfwXBGS61GqmtzIGwWwXFCD03uiKkka/NVyxeBiqzWzYV6IX2s9YX2cnkIt57IIdWh7C7VOakmGJrqjfPtHehuG/IKPQJTHzh1S6MU/Xda089Z5zV1T++GrjEudMFybsbkXv/3+d+V7C2QNinNz9bW08baZQpWHRmeqarFQV8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780384459; c=relaxed/simple; bh=ggB3SFUBedF/nHlI+XXyHFfTtUtAXXLVMDwiQrW5lDk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=XuR/TRdmK9sm2pUHYm4IJDP5KyYxWuteLsPVlxwfYZ6HnY3ONKBcsPNQSA7BZusZybtSZmwXRbKUkrAWZGPktTOger7btbvVWDiwt3h5JgGGe363GJnc52gdxJ8EtkzoUdkxjlzoL7bLrhVBKvypXA+J+YbA2q0Ja2YKC0o+aUA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=O+LtoKau; arc=none smtp.client-ip=95.215.58.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="O+LtoKau" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1780384452; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=x+yylFIMPR/8vrOHBFj2Pr0z/6HumSH0G5CRMfJ5N6s=; b=O+LtoKaurViSIY1QIl6wpYBx93vKk+sJHfgaPUGlIFpcnvCHvjRQyzI2DWuzqPHKK3EqdF kMFceXT9ig7ANx/7ovYlu4Fe163Zggooqpfj69+ntgw24nPmxA1FmFkjqQZDk/K13VxB2p In1E6t8Thyln3NPyIqLAKM0pyBFEUAw= From: Thorsten Blum To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Thorsten Blum , Christian Brauner , Tim Bird , Amir Goldstein Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next v2] net/dns_resolver: use kasprintf + kmemdup_nul to simplify dns_query Date: Tue, 2 Jun 2026 09:13:41 +0200 Message-ID: <20260602071343.962830-2-thorsten.blum@linux.dev> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1870; i=thorsten.blum@linux.dev; h=from:subject; bh=ggB3SFUBedF/nHlI+XXyHFfTtUtAXXLVMDwiQrW5lDk=; b=owGbwMvMwCUWt7pQ4caZUj3G02pJDFlyTcvzAidcucxoVfn4Gmfdp0tcO8JTHN/us7upbf8+r L6xwUO0o5SFQYyLQVZMkeXBrB8zfEtrKjeZROyEmcPKBDKEgYtTACay6CPDX8HFIauW3Tb12FMS Lqk6tYVx88r5ZwqXm03f9UXyX972Z0cYGW7FBFyQmP//U/Gd9oCNL3bwzRbdO0ftlGc7n+XJXPe K/8wA X-Developer-Key: i=thorsten.blum@linux.dev; a=openpgp; fpr=1D60735E8AEF3BE473B69D84733678FD8DFEEAD4 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Use kasprintf() for descriptions with a query type and kmemdup_nul() otherwise to simplify dns_query(). Signed-off-by: Thorsten Blum --- Changes in v2: - Reverse xmas tree (Jakub) - v1: https://lore.kernel.org/lkml/20260528222030.1655010-2-thorsten.blum@linux.dev/ --- net/dns_resolver/dns_query.c | 33 ++++++++------------------------- 1 file changed, 8 insertions(+), 25 deletions(-) diff --git a/net/dns_resolver/dns_query.c b/net/dns_resolver/dns_query.c index c250d82cad96..14bee83cbe22 100644 --- a/net/dns_resolver/dns_query.c +++ b/net/dns_resolver/dns_query.c @@ -64,44 +64,27 @@ int dns_query(struct net *net, const char *options, char **_result, time64_t *_expiry, bool invalidate) { - struct key *rkey; struct user_key_payload *upayload; - size_t typelen, desclen; - char *desc, *cp; + struct key *rkey; int ret, len; + char *desc; kenter("%s,%*.*s,%zu,%s", type, (int)namelen, (int)namelen, name, namelen, options); if (!name || namelen < 3 || namelen > 255) return -EINVAL; + if (type && *type == '\0') + return -EINVAL; /* construct the query key description as "[:]" */ - typelen = 0; - desclen = 0; - if (type) { - typelen = strlen(type); - if (typelen < 1) - return -EINVAL; - desclen += typelen + 1; - } - - desclen += namelen + 1; - - desc = kmalloc(desclen, GFP_KERNEL); + if (type) + desc = kasprintf(GFP_KERNEL, "%s:%.*s", type, (int)namelen, name); + else + desc = kmemdup_nul(name, namelen, GFP_KERNEL); if (!desc) return -ENOMEM; - cp = desc; - if (type) { - memcpy(cp, type, typelen); - cp += typelen; - *cp++ = ':'; - } - memcpy(cp, name, namelen); - cp += namelen; - *cp = '\0'; - if (!options) options = ""; kdebug("call request_key(,%s,%s)", desc, options);