From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-189.mta0.migadu.com (out-189.mta0.migadu.com [91.218.175.189]) (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 794B7328B62 for ; Mon, 25 May 2026 09:55:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779702903; cv=none; b=qh5GEtoLeULuCfB3P01cx+XPUmh1iM9+slPAcMezMyeMade/RBgd4PET2F7yjJN+XCxhaTy9turowo6H5zCftSgsWEwzTBDydv+gkLpqCuXACfGkKTWOXS0tveJ2iYpQ+gwIa6qaufQt68gU52nk0F5co+MPSqtpZ5bUMzqfizw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779702903; c=relaxed/simple; bh=dTwcgAi/dh/BQNuwqTIkwFUKF5W0dpplH2rKlAiqqww=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=KX0LAPUkkHh31bDhNYhPzjIfRUHfxBUiszzvC3558LY2b+ONPZbi/97HZNP8Qi1YpukCsMu8buYgd972D1PNW1NXr+xCw8gOmNMDHgbKYiH3cFI7EPWHiaI/SHPPiex3DWLklZBPbkF3CURIBJ64Tdr9LfZ5wSpoGVkJ/YMzgdY= 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=XXwJ1XV3; arc=none smtp.client-ip=91.218.175.189 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="XXwJ1XV3" 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=1779702898; 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=Mn8BCON48RNsbs65DnAKHB4VMspvtxbh062pndM79gk=; b=XXwJ1XV32ZhK/EOMIcDViuaMHI1wqrPWWp8B91z8rWLGg155SrJs8cCiMGb2CgiA2GwDzk /EI0eylKMOR11e82cD3CUykH0trWg9/uewNccyA/6wDZPvBkPo0Io+1EXgrqb9UGkmvHhm EtY7REpjpGhQmfRt+QP4A+uCqW8sbVc= From: Thorsten Blum To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Amir Goldstein , Tim Bird , Christian Brauner Cc: Thorsten Blum , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next] net/dns_resolver: consolidate namelen checks in dns_query Date: Mon, 25 May 2026 11:54:01 +0200 Message-ID: <20260525095400.821912-3-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=1003; i=thorsten.blum@linux.dev; h=from:subject; bh=dTwcgAi/dh/BQNuwqTIkwFUKF5W0dpplH2rKlAiqqww=; b=owGbwMvMwCUWt7pQ4caZUj3G02pJDFkiMhZu1ktbggtbyvz7DpoqnFQ/3TTv3+5rG9xeWa54f vJGmOSujlIWBjEuBlkxRZYHs37M8C2tqdxkErETZg4rE8gQBi5OAZgI831GhomfX52Yf+tyzISF 1+6nHNSYnTChTapp4uq8T40TZAtOJioyMtyqKlKLDLg68f9WHaO1K/yzxVd9PSmr0biDZ8qdXYH C8xgA X-Developer-Key: i=thorsten.blum@linux.dev; a=openpgp; fpr=1D60735E8AEF3BE473B69D84733678FD8DFEEAD4 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Consolidate the namelen checks and return -EINVAL early if needed. Drop the namelen == 0 check since it is covered by namelen < 3. Signed-off-by: Thorsten Blum --- net/dns_resolver/dns_query.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/net/dns_resolver/dns_query.c b/net/dns_resolver/dns_query.c index e1c09d7b8200..c250d82cad96 100644 --- a/net/dns_resolver/dns_query.c +++ b/net/dns_resolver/dns_query.c @@ -73,7 +73,7 @@ int dns_query(struct net *net, kenter("%s,%*.*s,%zu,%s", type, (int)namelen, (int)namelen, name, namelen, options); - if (!name || namelen == 0) + if (!name || namelen < 3 || namelen > 255) return -EINVAL; /* construct the query key description as "[:]" */ @@ -86,8 +86,6 @@ int dns_query(struct net *net, desclen += typelen + 1; } - if (namelen < 3 || namelen > 255) - return -EINVAL; desclen += namelen + 1; desc = kmalloc(desclen, GFP_KERNEL);