From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jason A. Donenfeld" Subject: [PATCH net-next v9 0/5] skb_to_sgvec hardening Date: Tue, 23 May 2017 18:05:45 +0200 Message-ID: <20170523160550.5203-1-Jason@zx2c4.com> Cc: "Jason A. Donenfeld" To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, davem@davemloft.net Return-path: Received: from frisell.zx2c4.com ([192.95.5.64]:51631 "EHLO frisell.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934937AbdEWQGB (ORCPT ); Tue, 23 May 2017 12:06:01 -0400 Sender: netdev-owner@vger.kernel.org List-ID: The recent bug with macsec and historical one with virtio have indicated that letting skb_to_sgvec trounce all over an sglist without checking the length is probably a bad idea. And it's not necessary either: an sglist already explicitly marks its last item, and the initialization functions are diligent in doing so. Thus there's a clear way of avoiding future overflows. So, this patchset, from a high level, makes skb_to_sgvec return a potential error code, and then adjusts all callers to check for the error code. There are two situations in which skb_to_sgvec might return such an error: 1) When the passed in sglist is too small; and 2) When the passed in skbuff is too deeply nested. So, the first patch in this series handles the issues with skb_to_sgvec directly, and the remaining ones then handle the call sites. Changes v8->v9: - Return correct errno in rxrpc, thanks to feedback from Dave Howells. Jason A. Donenfeld (5): skbuff: return -EMSGSIZE in skb_to_sgvec to prevent overflow ipsec: check return value of skb_to_sgvec always rxrpc: check return value of skb_to_sgvec always macsec: check return value of skb_to_sgvec always virtio_net: check return value of skb_to_sgvec always drivers/net/macsec.c | 13 ++++++++-- drivers/net/virtio_net.c | 9 +++++-- include/linux/skbuff.h | 8 +++--- net/core/skbuff.c | 65 +++++++++++++++++++++++++++++++----------------- net/ipv4/ah4.c | 8 ++++-- net/ipv4/esp4.c | 20 +++++++++------ net/ipv6/ah6.c | 8 ++++-- net/ipv6/esp6.c | 20 +++++++++------ net/rxrpc/rxkad.c | 19 ++++++++++---- 9 files changed, 116 insertions(+), 54 deletions(-) -- 2.13.0