linux-stable.git/net/ipv4/ip_gre.c, branch linux-5.14.y

ip_gre: validate csum_start only on pull

2021-09-22T10:39:32+00:00

[ Upstream commit 8a0ed250f911da31a2aef52101bc707846a800ff ]

The GRE tunnel device can pull existing outer headers in ipge_xmit.
This is a rare path, apparently unique to this device. The below
commit ensured that pulling does not move skb->data beyond csum_start.

But it has a false positive if ip_summed is not CHECKSUM_PARTIAL and
thus csum_start is irrelevant.

Refine to exclude this. At the same time simplify and strengthen the
test.

Simplify, by moving the check next to the offending pull, making it
more self documenting and removing an unnecessary branch from other
code paths.

Strengthen, by also ensuring that the transport header is correct and
therefore the inner headers will be after skb_reset_inner_headers.
The transport header is set to csum_start in skb_partial_csum_set.

Link: https://lore.kernel.org/netdev/YS+h%2FtqCJJiQei+W@shredder/
Fixes: 1d011c4803c7 ("ip_gre: add validation for csum_start")
Reported-by: Ido Schimmel 
Suggested-by: Alexander Duyck 
Signed-off-by: Willem de Bruijn 
Reviewed-by: Alexander Duyck 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ip_gre: add validation for csum_start

2021-08-22T20:24:40+00:00

Validate csum_start in gre_handle_offloads before we call _gre_xmit so
that we do not crash later when the csum_start value is used in the
lco_csum function call.

This patch deals with ipv4 code.

Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.")
Reported-by: syzbot+ff8e1b9f2f36481e2efc@syzkaller.appspotmail.com
Signed-off-by: Shreyansh Chouhan 
Reviewed-by: Willem de Bruijn 
Signed-off-by: David S. Miller

gre: let mac_header point to outer header only when necessary

2021-06-28T19:44:17+00:00

Commit e271c7b4420d ("gre: do not keep the GRE header around in collect
medata mode") did reset the mac_header for the collect_md case. Let's
extend this behaviour to classical gre devices as well.

ipgre_header_parse() seems to be the only case that requires mac_header
to point to the outer header. We can detect this case accurately by
checking ->header_ops. For all other cases, we can reset mac_header.

This allows to push an Ethernet header to ipgre packets and redirect
them to an Ethernet device:

  $ tc filter add dev gre0 ingress matchall          \
      action vlan push_eth dst_mac 00:00:5e:00:53:01 \
                           src_mac 00:00:5e:00:53:00 \
      action mirred egress redirect dev eth0

Before this patch, this worked only for collect_md gre devices.
Now this works for regular gre devices as well. Only the special case
of gre devices that use ipgre_header_ops isn't supported.

Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller

ipv4/ipv6: switch to dev_get_tstats64

2020-11-10T01:50:28+00:00

Replace ip_tunnel_get_stats64() with the new identical core function
dev_get_tstats64().

Signed-off-by: Heiner Kallweit 
Signed-off-by: Jakub Kicinski

ip_gre: set dev->hard_header_len and dev->needed_headroom properly

2020-10-14T01:35:29+00:00

GRE tunnel has its own header_ops, ipgre_header_ops, and sets it
conditionally. When it is set, it assumes the outer IP header is
already created before ipgre_xmit().

This is not true when we send packets through a raw packet socket,
where L2 headers are supposed to be constructed by user. Packet
socket calls dev_validate_header() to validate the header. But
GRE tunnel does not set dev->hard_header_len, so that check can
be simply bypassed, therefore uninit memory could be passed down
to ipgre_xmit(). Similar for dev->needed_headroom.

dev->hard_header_len is supposed to be the length of the header
created by dev->header_ops->create(), so it should be used whenever
header_ops is set, and dev->needed_headroom should be used when it
is not set.

Reported-and-tested-by: syzbot+4a2c52677a8a1aa283cb@syzkaller.appspotmail.com
Cc: William Tu 
Acked-by: Willem de Bruijn 
Signed-off-by: Cong Wang 
Acked-by: Xie He 
Signed-off-by: Jakub Kicinski

net: add a new ndo_tunnel_ioctl method

2020-05-19T22:45:11+00:00

This method is used to properly allow kernel callers of the IPv4 route
management ioctls.  The exsting ip_tunnel_ioctl helper is renamed to
ip_tunnel_ctl to better reflect that it doesn't directly implement ioctls
touching user memory, and is used for the guts of ndo_tunnel_ctl
implementations. A new ip_tunnel_ioctl helper is added that can be wired
up directly to the ndo_do_ioctl method and takes care of the copy to and
from userspace.

Signed-off-by: Christoph Hellwig 
Signed-off-by: David S. Miller

erspan: Check IFLA_GRE_ERSPAN_VER is set.

2020-05-12T20:11:41+00:00

Add a check to make sure the IFLA_GRE_ERSPAN_VER is provided by users.

Fixes: f989d546a2d5 ("erspan: Add type I version 0 support.")
Cc: Eric Dumazet 
Signed-off-by: William Tu 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

erspan: Add type I version 0 support.

2020-05-05T20:23:29+00:00

The Type I ERSPAN frame format is based on the barebones
IP + GRE(4-byte) encapsulation on top of the raw mirrored frame.
Both type I and II use 0x88BE as protocol type. Unlike type II
and III, no sequence number or key is required.
To creat a type I erspan tunnel device:
  $ ip link add dev erspan11 type erspan \
            local 172.16.1.100 remote 172.16.1.200 \
            erspan_ver 0

Signed-off-by: William Tu 
Signed-off-by: David S. Miller

net: ip_gre: Accept IFLA_INFO_DATA-less configuration

2020-03-17T00:19:56+00:00

The fix referenced below causes a crash when an ERSPAN tunnel is created
without passing IFLA_INFO_DATA. Fix by validating passed-in data in the
same way as ipgre does.

Fixes: e1f8f78ffe98 ("net: ip_gre: Separate ERSPAN newlink / changelink callbacks")
Reported-by: syzbot+1b4ebf4dae4e510dd219@syzkaller.appspotmail.com
Signed-off-by: Petr Machata 
Signed-off-by: David S. Miller

net: ip_gre: Separate ERSPAN newlink / changelink callbacks

2020-03-15T07:14:08+00:00

ERSPAN shares most of the code path with GRE and gretap code. While that
helps keep the code compact, it is also error prone. Currently a broken
userspace can turn a gretap tunnel into a de facto ERSPAN one by passing
IFLA_GRE_ERSPAN_VER. There has been a similar issue in ip6gretap in the
past.

To prevent these problems in future, split the newlink and changelink code
paths. Split the ERSPAN code out of ipgre_netlink_parms() into a new
function erspan_netlink_parms(). Extract a piece of common logic from
ipgre_newlink() and ipgre_changelink() into ipgre_newlink_encap_setup().
Add erspan_newlink() and erspan_changelink().

Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN")
Signed-off-by: Petr Machata 
Signed-off-by: David S. Miller