From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Eyal Birger <eyal.birger@gmail.com>,
"Jason A. Donenfeld" <Jason@zx2c4.com>,
Willem de Bruijn <willemb@google.com>,
Jakub Kicinski <kuba@kernel.org>
Subject: [PATCH 5.9 15/46] net/packet: fix packet receive on L3 devices without visible hard header
Date: Sun, 6 Dec 2020 12:17:23 +0100 [thread overview]
Message-ID: <20201206111557.197220214@linuxfoundation.org> (raw)
In-Reply-To: <20201206111556.455533723@linuxfoundation.org>
From: Eyal Birger <eyal.birger@gmail.com>
[ Upstream commit d549699048b4b5c22dd710455bcdb76966e55aa3 ]
In the patchset merged by commit b9fcf0a0d826
("Merge branch 'support-AF_PACKET-for-layer-3-devices'") L3 devices which
did not have header_ops were given one for the purpose of protocol parsing
on af_packet transmit path.
That change made af_packet receive path regard these devices as having a
visible L3 header and therefore aligned incoming skb->data to point to the
skb's mac_header. Some devices, such as ipip, xfrmi, and others, do not
reset their mac_header prior to ingress and therefore their incoming
packets became malformed.
Ideally these devices would reset their mac headers, or af_packet would be
able to rely on dev->hard_header_len being 0 for such cases, but it seems
this is not the case.
Fix by changing af_packet RX ll visibility criteria to include the
existence of a '.create()' header operation, which is used when creating
a device hard header - via dev_hard_header() - by upper layers, and does
not exist in these L3 devices.
As this predicate may be useful in other situations, add it as a common
dev_has_header() helper in netdevice.h.
Fixes: b9fcf0a0d826 ("Merge branch 'support-AF_PACKET-for-layer-3-devices'")
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20201121062817.3178900-1-eyal.birger@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/linux/netdevice.h | 5 +++++
net/packet/af_packet.c | 38 +++++++++++++++++++++-----------------
2 files changed, 26 insertions(+), 17 deletions(-)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3103,6 +3103,11 @@ static inline bool dev_validate_header(c
return false;
}
+static inline bool dev_has_header(const struct net_device *dev)
+{
+ return dev->header_ops && dev->header_ops->create;
+}
+
typedef int gifconf_func_t(struct net_device * dev, char __user * bufptr,
int len, int size);
int register_gifconf(unsigned int family, gifconf_func_t *gifconf);
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -93,38 +93,42 @@
/*
Assumptions:
- - if device has no dev->hard_header routine, it adds and removes ll header
- inside itself. In this case ll header is invisible outside of device,
- but higher levels still should reserve dev->hard_header_len.
- Some devices are enough clever to reallocate skb, when header
- will not fit to reserved space (tunnel), another ones are silly
- (PPP).
+ - If the device has no dev->header_ops->create, there is no LL header
+ visible above the device. In this case, its hard_header_len should be 0.
+ The device may prepend its own header internally. In this case, its
+ needed_headroom should be set to the space needed for it to add its
+ internal header.
+ For example, a WiFi driver pretending to be an Ethernet driver should
+ set its hard_header_len to be the Ethernet header length, and set its
+ needed_headroom to be (the real WiFi header length - the fake Ethernet
+ header length).
- packet socket receives packets with pulled ll header,
so that SOCK_RAW should push it back.
On receive:
-----------
-Incoming, dev->hard_header!=NULL
+Incoming, dev_has_header(dev) == true
mac_header -> ll header
data -> data
-Outgoing, dev->hard_header!=NULL
+Outgoing, dev_has_header(dev) == true
mac_header -> ll header
data -> ll header
-Incoming, dev->hard_header==NULL
- mac_header -> UNKNOWN position. It is very likely, that it points to ll
- header. PPP makes it, that is wrong, because introduce
- assymetry between rx and tx paths.
+Incoming, dev_has_header(dev) == false
+ mac_header -> data
+ However drivers often make it point to the ll header.
+ This is incorrect because the ll header should be invisible to us.
data -> data
-Outgoing, dev->hard_header==NULL
- mac_header -> data. ll header is still not built!
+Outgoing, dev_has_header(dev) == false
+ mac_header -> data. ll header is invisible to us.
data -> data
Resume
- If dev->hard_header==NULL we are unlikely to restore sensible ll header.
+ If dev_has_header(dev) == false we are unable to restore the ll header,
+ because it is invisible to us.
On transmit:
@@ -2066,7 +2070,7 @@ static int packet_rcv(struct sk_buff *sk
skb->dev = dev;
- if (dev->header_ops) {
+ if (dev_has_header(dev)) {
/* The device has an explicit notion of ll header,
* exported to higher levels.
*
@@ -2195,7 +2199,7 @@ static int tpacket_rcv(struct sk_buff *s
if (!net_eq(dev_net(dev), sock_net(sk)))
goto drop;
- if (dev->header_ops) {
+ if (dev_has_header(dev)) {
if (sk->sk_type != SOCK_DGRAM)
skb_push(skb, skb->data - skb_mac_header(skb));
else if (skb->pkt_type == PACKET_OUTGOING) {
next prev parent reply other threads:[~2020-12-06 11:46 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-06 11:17 [PATCH 5.9 00/46] 5.9.13-rc1 review Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 01/46] devlink: Hold rtnl lock while reading netdev attributes Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 02/46] devlink: Make sure devlink instance and port are in same net namespace Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 03/46] ipv6: addrlabel: fix possible memory leak in ip6addrlbl_net_init Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 04/46] net/af_iucv: set correct sk_protocol for child sockets Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 05/46] net: openvswitch: fix TTL decrement action netlink message format Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 06/46] net/tls: missing received data after fast remote close Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 07/46] net/tls: Protect from calling tls_dev_del for TLS RX twice Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 08/46] rose: Fix Null pointer dereference in rose_send_frame() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 09/46] sock: set sk_err to ee_errno on dequeue from errq Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 10/46] tcp: Set INET_ECN_xmit configuration in tcp_reinit_congestion_control Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 11/46] tun: honor IOCB_NOWAIT flag Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 12/46] usbnet: ipheth: fix connectivity with iOS 14 Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 13/46] vsock/virtio: discard packets only when socket is really closed Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 14/46] mptcp: fix NULL ptr dereference on bad MPJ Greg Kroah-Hartman
2020-12-06 11:17 ` Greg Kroah-Hartman [this message]
2020-12-06 11:17 ` [PATCH 5.9 16/46] netfilter: bridge: reset skb->pkt_type after NF_INET_POST_ROUTING traversal Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 17/46] ipv4: Fix tos mask in inet_rtm_getroute() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 18/46] dt-bindings: net: correct interrupt flags in examples Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 19/46] chelsio/chtls: fix panic during unload reload chtls Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 20/46] ibmvnic: Ensure that SCRQ entry reads are correctly ordered Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 21/46] ibmvnic: Fix TX completion error handling Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 22/46] tipc: fix incompatible mtu of transmission Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 23/46] inet_ecn: Fix endianness of checksum update when setting ECT(1) Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 24/46] geneve: pull IP header before ECN decapsulation Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 25/46] net: ip6_gre: set dev->hard_header_len when using header_ops Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 26/46] dpaa_eth: copy timestamp fields to new skb in A-050385 workaround Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 27/46] net/x25: prevent a couple of overflows Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 28/46] cxgb3: fix error return code in t3_sge_alloc_qset() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 29/46] net: pasemi: fix error return code in pasemi_mac_open() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 30/46] vxlan: fix error return code in __vxlan_dev_create() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 31/46] chelsio/chtls: fix a double free in chtls_setkey() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 32/46] net: mvpp2: Fix error return code in mvpp2_open() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 33/46] net: skbuff: ensure LSE is pullable before decrementing the MPLS ttl Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 34/46] net: openvswitch: ensure LSE is pullable before reading it Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 35/46] net/sched: act_mpls: " Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 36/46] net/mlx5: DR, Proper handling of unsupported Connect-X6DX SW steering Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 37/46] net/mlx5: Fix wrong address reclaim when command interface is down Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 38/46] net: mlx5e: fix fs_tcp.c build when IPV6 is not enabled Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 39/46] ALSA: usb-audio: US16x08: fix value count for level meters Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 40/46] Input: xpad - support Ardwiino Controllers Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 41/46] Input: i8042 - add ByteSpeed touchpad to noloop table Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 42/46] Input: atmel_mxt_ts - fix lost interrupts Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 43/46] tracing: Fix alignment of static buffer Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 44/46] tracing: Remove WARN_ON in start_thread() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 45/46] uapi: fix statx attribute value overlap for DAX & MOUNT_ROOT Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.9 46/46] drm/i915/gt: Fixup tgl mocs for PTE tracking Greg Kroah-Hartman
2020-12-06 21:08 ` [PATCH 5.9 00/46] 5.9.13-rc1 review Jeffrin Jose T
2020-12-07 7:17 ` Naresh Kamboju
2020-12-08 9:42 ` Greg Kroah-Hartman
2020-12-07 15:04 ` Jon Hunter
2020-12-08 9:43 ` Greg Kroah-Hartman
2020-12-07 15:55 ` Guenter Roeck
2020-12-08 9:43 ` Greg Kroah-Hartman
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