From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D85B7A95C for ; Wed, 23 Jul 2025 23:19:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753312769; cv=none; b=ih/jozqfhsnteC54jW8MH31CJcYosHdbhTQCFElkA8b2PBQPI3jGbGmXPAvSqY6AGBarAoOacX1ubULRxkCmN5A2Z4GZopVL3C32zlFAzCEQCDOWjaEHIpCekL/0eiiG3QHSrfYeM19tXbwP6hoAObSqGPLUz0DfZmlGmVFrqLE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753312769; c=relaxed/simple; bh=J3nOpgLdwswyRj4Ig/hSV5Xm2PjZFqZISJ9JUEnm30c=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=m/ekvijncQnIDSzRecmLoEk81GXGh7tMbsg4rXxoeBFDvy3Q/pHaQUNlqgwutUqyfp3eS1zxnU7dcIMgcVGVK6llOpRzK0KYaLf7vsayyhM16Jb+foqnG9Rkt2DuqbpXDD9Kjv+yDjuyjcxvdyNSyJ0x5u/4YwByEg2wEmztSCk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Zo8DaV4x; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Zo8DaV4x" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4FC48C4CEEF; Wed, 23 Jul 2025 23:19:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753312769; bh=J3nOpgLdwswyRj4Ig/hSV5Xm2PjZFqZISJ9JUEnm30c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Zo8DaV4xpI5B56porthD38Fl8h2Z6ALn2+jC17nNYwAYlEe5xIFu8vWGpv1dIXG+a iuX61LnazXXBqMavCoS49XMm3Ja9C9LOL6qVVkhA6yEzpnl9Hm+SOP4BT+ABstK7Z2 FVIDfGUP/bbUbshdohtxgZuvQsmdNIvK+L6aRyrtzmQ4uGQ7h8HC4o2o//FeRaakBD 1v4fYpBgw1CKuXTmG67JSD6A2YBRmUnKZhe8YTDVCWYdCgweDYDHDr24Va5TylOar1 uGGmIef8BDGzy6t0kV/Yv+18or27e3HIwuxujguj4iKlRFIgIrsDcW39eE1EBdMj3R 3xSriZJpWqoqQ== From: Kees Cook To: Jakub Kicinski Cc: Kees Cook , James Chapman , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , netdev@vger.kernel.org, Kuniyuki Iwashima , Willem de Bruijn Subject: [PATCH 2/6 net-next] net/l2tp: Add missing sa_family validation in pppol2tp_sockaddr_get_info Date: Wed, 23 Jul 2025 16:19:09 -0700 Message-Id: <20250723231921.2293685-2-kees@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250723230354.work.571-kees@kernel.org> References: <20250723230354.work.571-kees@kernel.org> 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=1539; i=kees@kernel.org; h=from:subject; bh=J3nOpgLdwswyRj4Ig/hSV5Xm2PjZFqZISJ9JUEnm30c=; b=owGbwMvMwCVmps19z/KJym7G02pJDBmNue//VzO2rntsGCa45nay2Jllq47MF1rEk3ryqmGYG Ndd7Q1tHaUsDGJcDLJiiixBdu5xLh5v28Pd5yrCzGFlAhnCwMUpABNZKMjwPzL+uhyr7AaN+sX6 T129V9qv+Rq40mHHzJvzG9/c+BbcG8zIcMzva1RVtoa4qIBArDdfY+LPggl+XcEt+qwZKftvrpR jAwA= X-Developer-Key: i=kees@kernel.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: 8bit While reviewing the struct proto_ops connect() and bind() callback implementations, I noticed that there doesn't appear to be any validation that AF_PPPOX sockaddr structures actually have sa_family set to AF_PPPOX. The pppol2tp_sockaddr_get_info() checks only look at the sizes. I don't see any way that this might actually cause problems as specific info fields are being populated, for which the existing size checks are correct, but it stood out as a missing address family check. Add the check and return -EAFNOSUPPORT on mismatch. Signed-off-by: Kees Cook --- Cc: James Chapman Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Simon Horman Cc: --- net/l2tp/l2tp_ppp.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index fc5c2fd8f34c..767b393cbb78 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -545,6 +545,13 @@ struct l2tp_connect_info { static int pppol2tp_sockaddr_get_info(const void *sa, int sa_len, struct l2tp_connect_info *info) { + const struct sockaddr_unspec *sockaddr = sa; + + if (sa_len < offsetofend(struct sockaddr, sa_family)) + return -EINVAL; + if (sockaddr->sa_family != AF_PPPOX) + return -EAFNOSUPPORT; + switch (sa_len) { case sizeof(struct sockaddr_pppol2tp): { -- 2.34.1