From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:58066 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752338AbcKRKhT (ORCPT ); Fri, 18 Nov 2016 05:37:19 -0500 Subject: Patch "net: mangle zero checksum in skb_checksum_help()" has been added to the 4.8-stable tree To: edumazet@google.com, davem@davemloft.net, gregkh@linuxfoundation.org, maze@google.com, willemb@google.com Cc: , From: Date: Fri, 18 Nov 2016 11:37:01 +0100 Message-ID: <1479465421181245@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled net: mangle zero checksum in skb_checksum_help() to the 4.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-mangle-zero-checksum-in-skb_checksum_help.patch and it can be found in the queue-4.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Fri Nov 18 11:35:46 CET 2016 From: Eric Dumazet Date: Sat, 29 Oct 2016 11:02:36 -0700 Subject: net: mangle zero checksum in skb_checksum_help() From: Eric Dumazet [ Upstream commit 4f2e4ad56a65f3b7d64c258e373cb71e8d2499f4 ] Sending zero checksum is ok for TCP, but not for UDP. UDPv6 receiver should by default drop a frame with a 0 checksum, and UDPv4 would not verify the checksum and might accept a corrupted packet. Simply replace such checksum by 0xffff, regardless of transport. This error was caught on SIT tunnels, but seems generic. Signed-off-by: Eric Dumazet Cc: Maciej Żenczykowski Cc: Willem de Bruijn Acked-by: Maciej Żenczykowski Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2484,7 +2484,7 @@ int skb_checksum_help(struct sk_buff *sk goto out; } - *(__sum16 *)(skb->data + offset) = csum_fold(csum); + *(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0; out_set_summed: skb->ip_summed = CHECKSUM_NONE; out: Patches currently in stable-queue which might be from edumazet@google.com are queue-4.8/net-__skb_flow_dissect-must-cap-its-return-value.patch queue-4.8/tcp-take-care-of-truncations-done-by-sk_filter.patch queue-4.8/net-clear-sk_err_soft-in-sk_clone_lock.patch queue-4.8/dccp-do-not-release-listeners-too-soon.patch queue-4.8/net-mangle-zero-checksum-in-skb_checksum_help.patch queue-4.8/tcp-fix-return-value-for-partial-writes.patch queue-4.8/ipv6-dccp-fix-out-of-bound-access-in-dccp_v6_err.patch queue-4.8/ipv6-dccp-add-missing-bind_conflict-to-dccp_ipv6_mapped.patch queue-4.8/tcp-fix-potential-memory-corruption.patch queue-4.8/dccp-do-not-send-reset-to-already-closed-sockets.patch queue-4.8/dccp-fix-out-of-bound-access-in-dccp_v4_err.patch queue-4.8/sock-fix-sendmmsg-for-partial-sendmsg.patch