linux/net
Matthias Schiffer 3e59e88567 net: l2tp: reduce log level of messages in receive path, add counter instead
Commit 5ee759cda5 ("l2tp: use standard API for warning log messages")
changed a number of warnings about invalid packets in the receive path
so that they are always shown, instead of only when a special L2TP debug
flag is set. Even with rate limiting these warnings can easily cause
significant log spam - potentially triggered by a malicious party
sending invalid packets on purpose.

In addition these warnings were noticed by projects like Tunneldigger [1],
which uses L2TP for its data path, but implements its own control
protocol (which is sufficiently different from L2TP data packets that it
would always be passed up to userspace even with future extensions of
L2TP).

Some of the warnings were already redundant, as l2tp_stats has a counter
for these packets. This commit adds one additional counter for invalid
packets that are passed up to userspace. Packets with unknown session are
not counted as invalid, as there is nothing wrong with the format of
these packets.

With the additional counter, all of these messages are either redundant
or benign, so we reduce them to pr_debug_ratelimited().

[1] https://github.com/wlanslovenija/tunneldigger/issues/160

Fixes: 5ee759cda5 ("l2tp: use standard API for warning log messages")
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-03 16:55:02 -08:00
..
6lowpan
9p net: remove redundant 'depends on NET' 2021-01-27 17:04:12 -08:00
802
8021q Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-01-14 18:34:50 -08:00
appletalk appletalk: Fix skb allocation size in loopback case 2021-02-12 16:40:28 -08:00
atm net: atm: pppoatm: use new API for wakeup tasklet 2021-01-29 18:24:05 -08:00
ax25
batman-adv This feature/cleanup patchset is an updated version of the pull request 2021-02-08 11:32:40 -08:00
bluetooth Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kern 2021-02-11 14:59:01 -08:00
bpf Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-01-20 12:16:11 -08:00
bpfilter net: remove redundant 'depends on NET' 2021-01-27 17:04:12 -08:00
bridge bridge: mrp: Update br_mrp to use new return values of br_mrp_switchdev 2021-02-16 14:47:46 -08:00
caif net: caif: Use netif_rx_any_context(). 2021-02-15 13:21:48 -08:00
can net: introduce CAN specific pointer in the struct net_device 2021-02-24 14:32:15 -08:00
ceph libceph: remove osdtimeout option entirely 2021-02-16 12:09:52 +01:00
core net: expand textsearch ts_state to fit skb_seq_state 2021-03-01 15:25:24 -08:00
dcb net: dcb: use obj-$(CONFIG_DCB) form in net/Makefile 2021-01-27 17:03:52 -08:00
dccp dccp: Return the correct errno code 2021-02-06 11:15:28 -08:00
decnet net: decnet: fix netdev refcount leaking on error path 2021-01-27 17:33:46 -08:00
dns_resolver net: remove redundant 'depends on NET' 2021-01-27 17:04:12 -08:00
dsa net: dsa: tag_mtk: fix 802.1ad VLAN egress 2021-03-01 15:29:43 -08:00
ethernet net: datagram: fix some kernel-doc markups 2020-11-17 14:15:03 -08:00
ethtool ethtool: fix the check logic of at least one channel for RX/TX 2021-02-28 11:49:07 -08:00
hsr net: hsr: add support for EntryForgetTime 2021-02-25 09:41:51 -08:00
ieee802154 treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
ife net: remove redundant 'depends on NET' 2021-01-27 17:04:12 -08:00
ipv4 tcp: add sanity tests to TCP_QUEUE_SEQ 2021-03-01 15:32:05 -08:00
ipv6 net: always use icmp{,v6}_ndo_send from ndo_start_xmit 2021-03-01 13:11:35 -08:00
iucv net/af_iucv: build SG skbs for TRANS_HIPER sockets 2021-01-28 20:36:22 -08:00
kcm net: group skb_shinfo zerocopy related bits together. 2021-01-07 16:08:37 -08:00
key af_key: relax availability checks for skb size calculation 2021-01-04 10:05:50 +01:00
l2tp net: l2tp: reduce log level of messages in receive path, add counter instead 2021-03-03 16:55:02 -08:00
l3mdev net: l3mdev: use obj-$(CONFIG_NET_L3_MASTER_DEV) form in net/Makefile 2021-01-27 17:03:52 -08:00
lapb net: lapb: Copy the skb before sending a packet 2021-02-02 08:40:48 -08:00
llc net: remove redundant 'depends on NET' 2021-01-27 17:04:12 -08:00
mac80211 cfg80211/mac80211: Support disabling HE mode 2021-02-12 09:33:34 +01:00
mac802154 net: mac802154: convert tasklets to use new tasklet_setup() API 2020-11-07 10:40:56 -08:00
mpls mpls: drop skb's dst in mpls_forward() 2020-11-03 12:55:53 -08:00
mptcp mptcp: do not wakeup listener for MPJ subflows 2021-02-22 18:54:59 -08:00
ncsi net/ncsi: Use real net-device for response handler 2020-12-23 12:22:23 -08:00
netfilter netfilter: nftables: introduce table ownership 2021-02-15 18:17:15 +01:00
netlabel Merge https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-11-19 19:08:46 -08:00
netlink mptcp: avoid lock_fast usage in accept path 2021-02-12 16:31:46 -08:00
netrom
nfc TTY/Serial driver changes for 5.12-rc1 2021-02-20 21:28:04 -08:00
nsh
openvswitch net: openvswitch: add log message for error case 2021-01-14 16:32:14 -08:00
packet net/packet: Improve the comment about LL header visibility criteria 2021-02-06 14:59:28 -08:00
phonet
psample net: psample: Fix netlink skb length with tunnel info 2021-02-25 09:49:46 -08:00
qrtr net/qrtr: fix __netdev_alloc_skb call 2021-03-01 13:24:03 -08:00
rds net/rds: restrict iovecs length for RDS_CMSG_RDMA_ARGS 2021-02-02 08:44:08 -08:00
rfkill rfkill: add a reason to the HW rfkill state 2020-12-11 12:47:17 +01:00
rose rose: Fix Null pointer dereference in rose_send_frame() 2020-11-20 10:04:58 -08:00
rxrpc rxrpc: Fix dependency on IPv6 in udp tunnel config 2021-02-12 16:42:05 -08:00
sched net/sched: cls_flower: validate ct_state for invalid and reply flags 2021-02-23 12:23:44 -08:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-02-10 13:30:12 -08:00
smc net/smc: use memcpy instead of snprintf to avoid out of bounds read 2021-01-12 20:22:01 -08:00
strparser
sunrpc Optimization: 2021-02-22 13:29:55 -08:00
switchdev net: bridge: propagate extack through switchdev_port_attr_set 2021-02-14 17:38:11 -08:00
tipc tipc: remove duplicated code in tipc_msg_create 2021-01-27 18:50:07 -08:00
tls net/tls: Select SOCK_RX_QUEUE_MAPPING from TLS_DEVICE 2021-02-11 19:08:06 -08:00
unix af_unix: handle idmapped mounts 2021-01-24 14:27:18 +01:00
vmw_vsock vsock: fix locking in vsock_shutdown() 2021-02-09 15:31:22 -08:00
wireless cfg80211/mac80211: Support disabling HE mode 2021-02-12 09:33:34 +01:00
x25 net: x25: Remove unimplemented X.25-over-LLC code stubs 2020-12-12 17:15:33 -08:00
xdp xsk: Fold xp_assign_dev and __xp_assign_dev 2021-01-25 23:56:33 +01:00
xfrm Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2021-02-09 11:23:41 -08:00
compat.c iov_iter: transparently handle compat iovecs in import_iovec 2020-10-03 00:02:13 -04:00
devres.c
Kconfig net/sock: Add kernel config SOCK_RX_QUEUE_MAPPING 2021-02-11 19:08:06 -08:00
Makefile net: l3mdev: use obj-$(CONFIG_NET_L3_MASTER_DEV) form in net/Makefile 2021-01-27 17:03:52 -08:00
socket.c idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
sysctl_net.c