From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Antoine Tenart <atenart@kernel.org>,
Florian Westphal <fw@strlen.de>, Jakub Kicinski <kuba@kernel.org>
Subject: [PATCH 4.4 05/39] netfilter: bridge: reset skb->pkt_type after NF_INET_POST_ROUTING traversal
Date: Thu, 10 Dec 2020 15:26:16 +0100 [thread overview]
Message-ID: <20201210142601.155596416@linuxfoundation.org> (raw)
In-Reply-To: <20201210142600.887734129@linuxfoundation.org>
From: Antoine Tenart <atenart@kernel.org>
[ Upstream commit 44f64f23bae2f0fad25503bc7ab86cd08d04cd47 ]
Netfilter changes PACKET_OTHERHOST to PACKET_HOST before invoking the
hooks as, while it's an expected value for a bridge, routing expects
PACKET_HOST. The change is undone later on after hook traversal. This
can be seen with pairs of functions updating skb>pkt_type and then
reverting it to its original value:
For hook NF_INET_PRE_ROUTING:
setup_pre_routing / br_nf_pre_routing_finish
For hook NF_INET_FORWARD:
br_nf_forward_ip / br_nf_forward_finish
But the third case where netfilter does this, for hook
NF_INET_POST_ROUTING, the packet type is changed in br_nf_post_routing
but never reverted. A comment says:
/* We assume any code from br_dev_queue_push_xmit onwards doesn't care
* about the value of skb->pkt_type. */
But when having a tunnel (say vxlan) attached to a bridge we have the
following call trace:
br_nf_pre_routing
br_nf_pre_routing_ipv6
br_nf_pre_routing_finish
br_nf_forward_ip
br_nf_forward_finish
br_nf_post_routing <- pkt_type is updated to PACKET_HOST
br_nf_dev_queue_xmit <- but not reverted to its original value
vxlan_xmit
vxlan_xmit_one
skb_tunnel_check_pmtu <- a check on pkt_type is performed
In this specific case, this creates issues such as when an ICMPv6 PTB
should be sent back. When CONFIG_BRIDGE_NETFILTER is enabled, the PTB
isn't sent (as skb_tunnel_check_pmtu checks if pkt_type is PACKET_HOST
and returns early).
If the comment is right and no one cares about the value of
skb->pkt_type after br_dev_queue_push_xmit (which isn't true), resetting
it to its original value should be safe.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20201123174902.622102-1-atenart@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/bridge/br_netfilter_hooks.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c
@@ -711,6 +711,11 @@ static int br_nf_dev_queue_xmit(struct n
mtu_reserved = nf_bridge_mtu_reduction(skb);
mtu = skb->dev->mtu;
+ if (nf_bridge->pkt_otherhost) {
+ skb->pkt_type = PACKET_OTHERHOST;
+ nf_bridge->pkt_otherhost = false;
+ }
+
if (nf_bridge->frag_max_size && nf_bridge->frag_max_size < mtu)
mtu = nf_bridge->frag_max_size;
@@ -804,8 +809,6 @@ static unsigned int br_nf_post_routing(v
else
return NF_ACCEPT;
- /* We assume any code from br_dev_queue_push_xmit onwards doesn't care
- * about the value of skb->pkt_type. */
if (skb->pkt_type == PACKET_OTHERHOST) {
skb->pkt_type = PACKET_HOST;
nf_bridge->pkt_otherhost = true;
next prev parent reply other threads:[~2020-12-10 14:30 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-10 14:26 [PATCH 4.4 00/39] 4.4.248-rc1 review Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 01/39] net/af_iucv: set correct sk_protocol for child sockets Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 02/39] rose: Fix Null pointer dereference in rose_send_frame() Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 03/39] usbnet: ipheth: fix connectivity with iOS 14 Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 04/39] bonding: wait for sysfs kobject destruction before freeing struct slave Greg Kroah-Hartman
2020-12-10 14:26 ` Greg Kroah-Hartman [this message]
2020-12-10 14:26 ` [PATCH 4.4 06/39] net/x25: prevent a couple of overflows Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 07/39] cxgb3: fix error return code in t3_sge_alloc_qset() Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 08/39] net: pasemi: fix error return code in pasemi_mac_open() Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 09/39] dt-bindings: net: correct interrupt flags in examples Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 10/39] Input: xpad - support Ardwiino Controllers Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 11/39] Input: i8042 - add ByteSpeed touchpad to noloop table Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 12/39] powerpc: Stop exporting __clear_user which is now inlined Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 13/39] btrfs: sysfs: init devices outside of the chunk_mutex Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 14/39] vlan: consolidate VLAN parsing code and limit max parsing depth Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 15/39] geneve: pull IP header before ECN decapsulation Greg Kroah-Hartman
2020-12-10 14:32 ` Eric Dumazet
2020-12-10 14:38 ` Greg Kroah-Hartman
2020-12-10 14:40 ` Greg Kroah-Hartman
2020-12-10 14:53 ` Eric Dumazet
2020-12-10 15:36 ` Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 16/39] usb: gadget: f_fs: Use local copy of descriptors for userspace copy Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 17/39] USB: serial: kl5kusb105: fix memleak on open Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 18/39] USB: serial: ch341: add new Product ID for CH341A Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 19/39] USB: serial: ch341: sort device-id entries Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 20/39] USB: serial: option: add Fibocom NL668 variants Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 21/39] USB: serial: option: add support for Thales Cinterion EXS82 Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 22/39] tty: Fix ->pgrp locking in tiocspgrp() Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 23/39] ALSA: hda/realtek - Add new codec supported for ALC897 Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 24/39] ALSA: hda/generic: Add option to enforce preferred_dacs pairs Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 25/39] tty: Fix ->session locking Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 26/39] cifs: fix potential use-after-free in cifs_echo_request() Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 27/39] i2c: imx: Fix reset of I2SR_IAL flag Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 28/39] i2c: imx: Check for I2SR_IAL after every byte Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 29/39] arm64: assembler: make adr_l work in modules under KASLR Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 30/39] iommu/amd: Set DTE[IntTabLen] to represent 512 IRTEs Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 31/39] spi: Introduce device-managed SPI controller allocation Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 32/39] spi: bcm2835: Fix use-after-free on unbind Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 33/39] spi: bcm2835: Release the DMA channel if probe fails after dma_init Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 34/39] tracing: Fix userstacktrace option for instances Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 35/39] btrfs: cleanup cow block on error Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 36/39] mm/userfaultfd: do not access vma->vm_mm after calling handle_userfault() Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 37/39] gfs2: check for empty rgrp tree in gfs2_ri_update Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 38/39] Input: i8042 - fix error return code in i8042_setup_aux() Greg Kroah-Hartman
2020-12-10 14:26 ` [PATCH 4.4 39/39] x86/uprobes: Do not use prefixes.nbytes when looping over prefixes.bytes Greg Kroah-Hartman
2020-12-10 20:37 ` [PATCH 4.4 00/39] 4.4.248-rc1 review Pavel Machek
2020-12-10 21:24 ` Shuah Khan
2020-12-11 0:05 ` Guenter Roeck
2020-12-11 12:06 ` Naresh Kamboju
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