linux/include/net
Jason A. Donenfeld ee576c47db net: icmp: pass zeroed opts from icmp{,v6}_ndo_send before sending
The icmp{,v6}_send functions make all sorts of use of skb->cb, casting
it with IPCB or IP6CB, assuming the skb to have come directly from the
inet layer. But when the packet comes from the ndo layer, especially
when forwarded, there's no telling what might be in skb->cb at that
point. As a result, the icmp sending code risks reading bogus memory
contents, which can result in nasty stack overflows such as this one
reported by a user:

    panic+0x108/0x2ea
    __stack_chk_fail+0x14/0x20
    __icmp_send+0x5bd/0x5c0
    icmp_ndo_send+0x148/0x160

In icmp_send, skb->cb is cast with IPCB and an ip_options struct is read
from it. The optlen parameter there is of particular note, as it can
induce writes beyond bounds. There are quite a few ways that can happen
in __ip_options_echo. For example:

    // sptr/skb are attacker-controlled skb bytes
    sptr = skb_network_header(skb);
    // dptr/dopt points to stack memory allocated by __icmp_send
    dptr = dopt->__data;
    // sopt is the corrupt skb->cb in question
    if (sopt->rr) {
        optlen  = sptr[sopt->rr+1]; // corrupt skb->cb + skb->data
        soffset = sptr[sopt->rr+2]; // corrupt skb->cb + skb->data
	// this now writes potentially attacker-controlled data, over
	// flowing the stack:
        memcpy(dptr, sptr+sopt->rr, optlen);
    }

In the icmpv6_send case, the story is similar, but not as dire, as only
IP6CB(skb)->iif and IP6CB(skb)->dsthao are used. The dsthao case is
worse than the iif case, but it is passed to ipv6_find_tlv, which does
a bit of bounds checking on the value.

This is easy to simulate by doing a `memset(skb->cb, 0x41,
sizeof(skb->cb));` before calling icmp{,v6}_ndo_send, and it's only by
good fortune and the rarity of icmp sending from that context that we've
avoided reports like this until now. For example, in KASAN:

    BUG: KASAN: stack-out-of-bounds in __ip_options_echo+0xa0e/0x12b0
    Write of size 38 at addr ffff888006f1f80e by task ping/89
    CPU: 2 PID: 89 Comm: ping Not tainted 5.10.0-rc7-debug+ #5
    Call Trace:
     dump_stack+0x9a/0xcc
     print_address_description.constprop.0+0x1a/0x160
     __kasan_report.cold+0x20/0x38
     kasan_report+0x32/0x40
     check_memory_region+0x145/0x1a0
     memcpy+0x39/0x60
     __ip_options_echo+0xa0e/0x12b0
     __icmp_send+0x744/0x1700

Actually, out of the 4 drivers that do this, only gtp zeroed the cb for
the v4 case, while the rest did not. So this commit actually removes the
gtp-specific zeroing, while putting the code where it belongs in the
shared infrastructure of icmp{,v6}_ndo_send.

This commit fixes the issue by passing an empty IPCB or IP6CB along to
the functions that actually do the work. For the icmp_send, this was
already trivial, thanks to __icmp_send providing the plumbing function.
For icmpv6_send, this required a tiny bit of refactoring to make it
behave like the v4 case, after which it was straight forward.

Fixes: a2b78e9b2c ("sunvnet: generate ICMP PTMUD messages for smaller port MTUs")
Reported-by: SinYu <liuxyon@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/netdev/CAF=yD-LOF116aHub6RMe8vB8ZpnrrnoTdqhobEx+bvoA8AsP0w@mail.gmail.com/T/
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20210223131858.72082-1-Jason@zx2c4.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-23 11:29:52 -08:00
..
9p 9p: apply review requests for fid refcounting 2020-11-19 17:21:34 +01:00
bluetooth Bluetooth: Skip eSCO 2M params when not supported 2021-02-01 17:04:17 +01:00
caif net: caif: Remove unused caif SPI driver 2020-09-29 14:02:53 -07:00
iucv net/af_iucv: don't track individual TX skbs for TRANS_HIPER sockets 2021-01-28 20:36:21 -08:00
netfilter netfilter: nftables: introduce table ownership 2021-02-15 18:17:15 +01:00
netns net: ipv6: Emit notification when fib hardware flags are changed 2021-02-02 17:45:59 -08:00
nfc net/nfc/nci: Support NCI 2.x initial sequence 2020-12-04 17:47:35 -08:00
phonet treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 336 2019-06-05 17:37:07 +02:00
sctp sctp: bring inet(6)_skb_parm back to sctp_input_cb 2020-11-05 14:27:30 -08:00
tc_act Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-10-15 12:43:21 -07:00
6lowpan.h 6lowpan: Replace zero-length array with flexible-array member 2020-02-28 14:51:30 +01:00
act_api.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-02-16 17:51:13 -08:00
addrconf.h ipv6: some fixes for ipv6_dev_find() 2020-08-18 15:58:53 -07:00
af_ieee802154.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
af_rxrpc.h rxrpc: Make rxrpc_kernel_get_srtt() indicate validity 2020-08-20 18:21:28 +01:00
af_unix.h unix: uses an atomic type for scm files accounting 2020-02-28 12:12:53 -08:00
af_vsock.h vsock: add local transport support in the vsock core 2019-12-11 15:01:23 -08:00
ah.h
arp.h net: avoid potential false sharing in neighbor related code 2019-11-06 16:14:48 -08:00
atmclip.h
ax25.h ax25: fix possible use-after-free 2019-01-23 11:18:00 -08:00
ax88796.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
bareudp.h bareudp: Reverted support to enable & disable rx metadata collection 2020-07-21 18:30:47 -07:00
bond_3ad.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 90 2019-05-24 17:37:53 +02:00
bond_alb.h bonding/alb: Add helper functions to get the xmit slave 2020-05-01 12:15:37 -07:00
bond_options.h bonding: add an option to specify a delay between peer notifications 2019-07-04 12:30:48 -07:00
bonding.h net/bonding: Declare TLS RX device offload support 2021-01-18 20:48:40 -08:00
bpf_sk_storage.h bpf: Allow using bpf_sk_storage in FENTRY/FEXIT/RAW_TP 2020-11-12 18:39:28 -08:00
busy_poll.h net, xdp, xsk: fix __sk_mark_napi_id_once napi_id error 2020-12-01 15:51:19 +01:00
calipso.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
cfg80211-wext.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
cfg80211.h cfg80211/mac80211: Support disabling HE mode 2021-02-12 09:33:34 +01:00
cfg802154.h cfg802154: Replace zero-length array with flexible-array member 2020-02-29 14:39:08 +01:00
checksum.h saner calling conventions for csum_and_copy_..._user() 2020-08-20 15:45:15 -04:00
cipso_ipv4.h cipso: Remove unused inline functions 2020-07-15 07:45:24 -07:00
cls_cgroup.h bpf: Allow to retrieve cgroup v1 classid from v2 hooks 2020-03-27 19:40:38 -07:00
codel_impl.h
codel_qdisc.h
codel.h
compat.h compat: always include linux/compat.h from net/compat.h 2020-11-23 13:31:54 -08:00
datalink.h
dcbevent.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
dcbnl.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
devlink.h devlink: Fix dmac_filter trap name, align to its documentation 2021-02-11 13:04:49 -08:00
dn_dev.h
dn_fib.h net: dn_fib: Replace zero-length array with flexible-array member 2020-02-29 21:52:20 -08:00
dn_neigh.h
dn_nsp.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 24 2019-05-21 11:52:39 +02:00
dn_route.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 24 2019-05-21 11:52:39 +02:00
dn.h
dsa.h net: dsa: add MRP support 2021-02-16 14:47:46 -08:00
dsfield.h ipv6: Annotate bitwise IPv6 dsfield pointer cast 2019-12-16 16:09:44 -08:00
dst_cache.h
dst_metadata.h
dst_ops.h net/dst: use a smaller percpu_counter batch for dst entries accounting 2020-05-08 21:33:33 -07:00
dst.h net: indirect call helpers for ipv4/ipv6 dst_check functions 2021-02-03 14:51:40 -08:00
erspan.h erspan: Add type I version 0 support. 2020-05-05 13:23:29 -07:00
esp.h ESP: Export esp_output_fill_trailer function 2020-02-19 13:52:32 +01:00
espintcp.h xfrm: espintcp: save and call old ->sk_destruct 2020-04-20 07:34:16 +02:00
ethoc.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
failover.h
fib_notifier.h ipv6: Remove old route notifications and convert listeners 2019-12-24 22:37:30 -08:00
fib_rules.h fib: use indirect call wrappers in the most common fib_rules_ops 2020-07-28 17:42:31 -07:00
firewire.h
flow_dissector.h net/flow_dissector: add packet hash dissection 2020-07-24 15:23:31 -07:00
flow_offload.h net: flow_offload: Add original direction flag to ct_metadata 2021-01-29 18:05:30 -08:00
flow.h lsm,selinux: pass flowi_common instead of flowi to the LSM hooks 2020-11-23 18:36:21 -05:00
fou.h
fq_impl.h net/fq_impl: do not maintain a backlog-sorted list of flows 2021-01-21 13:33:45 +01:00
fq.h net/fq_impl: do not maintain a backlog-sorted list of flows 2021-01-21 13:33:45 +01:00
garp.h treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
gen_stats.h net_sched: extend packet counter to 64bit 2019-11-05 18:20:55 -08:00
genetlink.h mptcp: avoid lock_fast usage in accept path 2021-02-12 16:31:46 -08:00
geneve.h net: Move the definition of the default Geneve udp port to public header file 2019-03-22 12:09:31 -07:00
gre.h ip_gre: add csum offload support for gre header 2021-01-29 20:39:14 -08:00
gro_cells.h
gro.h net/core: move gro function declarations to separate header 2021-02-04 18:37:57 -08:00
gtp.h
gue.h GUE: Fix a typo 2020-06-22 21:12:44 -07:00
hwbm.h net: hwbm: if CONFIG_NET_HWBM unset, make stub functions static 2019-10-25 16:24:32 -07:00
icmp.h net: icmp: pass zeroed opts from icmp{,v6}_ndo_send before sending 2021-02-23 11:29:52 -08:00
ieee80211_radiotap.h mac80211: add radiotap flag to assure frames are not reordered 2020-11-06 11:01:01 +01:00
ieee802154_netdev.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
if_inet6.h ipv6: Replace zero-length array with flexible-array 2020-05-11 13:18:54 -07:00
ife.h net: ife: drop include of module.h from net/ife.h 2019-04-22 21:50:53 -07:00
ila.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet6_connection_sock.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet6_hashtables.h net: Track socket refcounts in skb_steal_sock() 2020-03-30 13:45:04 -07:00
inet_common.h bpf: Allow rewriting to ports under ip_unprivileged_port_start 2021-01-27 18:18:15 -08:00
inet_connection_sock.h tcp: shrink inet_connection_sock icsk_mtup enabled and probe_size 2021-01-29 22:48:30 -08:00
inet_ecn.h inet_ecn: Use csum16_add() helper for IP_ECN_set_* helpers 2020-12-14 18:38:58 -08:00
inet_frag.h inet: frags: batch fqdir destroy works 2020-12-12 15:08:54 -08:00
inet_hashtables.h tcp: fix race condition when creating child sockets from syncookies 2020-11-23 16:32:33 -08:00
inet_sock.h inet: remove inet_sk_copy_descendant() 2020-08-26 07:33:19 -07:00
inet_timewait_sock.h tcp: honor SO_PRIORITY in TIME_WAIT state 2019-09-27 12:05:02 +02:00
inetpeer.h net: ipv4: use a dedicated counter for icmp_v4 redirect packets 2019-02-08 21:50:15 -08:00
ip6_checksum.h tcp: remove indirect calls for icsk->icsk_af_ops->send_check 2020-06-20 17:47:53 -07:00
ip6_fib.h IPv6: Add "offload failed" indication to routes 2021-02-08 16:47:03 -08:00
ip6_route.h net: allow user to set metric on default route learned via Router Advertisement 2021-01-26 18:39:45 -08:00
ip6_tunnel.h ip6_tunnel: allow not to count pkts on tstats by passing dev as NULL 2019-06-18 20:48:45 -04:00
ip_fib.h IPv4: Add "offload failed" indication to routes 2021-02-08 16:47:03 -08:00
ip_tunnels.h Merge https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-11-19 19:08:46 -08:00
ip_vs.h netfilter: move handlers to net/ip_vs.h 2021-02-04 18:37:57 -08:00
ip.h inet: constify inet_sdif() argument 2020-11-10 17:56:54 -08:00
ipcomp.h
ipconfig.h
ipv6_frag.h ipv6: Remove dependency of ipv6_frag_thdr_truncated on ipv6 module 2020-11-19 10:49:50 -08:00
ipv6_stubs.h ipv6: add ipv6_fragment hook in ipv6_stub 2020-08-31 12:26:39 -07:00
ipv6.h ipv6: Remove dependency of ipv6_frag_thdr_truncated on ipv6 module 2020-11-19 10:49:50 -08:00
ipx.h bonding/alb: properly access headers in bond_alb_xmit() 2020-02-05 14:28:09 +01:00
iw_handler.h
kcm.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
l3mdev.h l3mdev: add infrastructure for table to VRF mapping 2020-06-20 17:22:22 -07:00
lag.h
lapb.h net: lapb: Add locking to the lapb module 2021-01-26 17:53:45 -08:00
lib80211.h
llc_c_ac.h
llc_c_ev.h
llc_c_st.h
llc_conn.h llc: fix sk_buff leak in llc_conn_service() 2019-10-08 13:23:05 -07:00
llc_if.h
llc_pdu.h
llc_s_ac.h
llc_s_ev.h
llc_s_st.h
llc_sap.h
llc.h
lwtunnel.h net: add net available in build_state 2020-03-29 22:30:57 -07:00
mac80211.h cfg80211: avoid holding the RTNL when calling the driver 2021-01-26 11:55:50 +01:00
mac802154.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
macsec.h net: macsec: add support for getting offloaded stats 2020-03-26 20:17:36 -07:00
mip6.h net: mip6: Replace zero-length array with flexible-array member 2020-03-02 11:16:27 -08:00
mld.h net: ipv6: mld: Replace zero-length array with flexible-array member 2020-02-29 21:52:20 -08:00
mpls_iptunnel.h net: mpls: Replace zero-length array with flexible-array member 2020-02-28 12:08:37 -08:00
mpls.h net: Make mpls_entry_encode() available for generic users 2020-05-29 21:20:20 -07:00
mptcp.h mptcp: add port support for ADD_ADDR suboption writing 2020-12-09 19:02:15 -08:00
mrp.h treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
ncsi.h
ndisc.h ipv6: ndisc: adjust ndisc_ifinfo_sysctl_change prototype 2020-08-24 06:40:07 -07:00
neighbour.h net: Exempt multicast addresses from five-second neighbor lifetime 2020-11-13 14:24:39 -08:00
net_failover.h
net_namespace.h net: initialize net->net_cookie at netns setup 2021-02-11 14:10:07 -08:00
net_ratelimit.h
netevent.h
netlabel.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
netlink.h treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
netprio_cgroup.h netprio: use css ID instead of cgroup ID 2019-11-12 08:18:03 -08:00
netrom.h net: netrom: Fix error cleanup path of nr_proto_init 2019-04-11 13:59:49 -07:00
nexthop.h nexthop: Use enum to encode notification type 2021-01-28 20:49:52 -08:00
nl802154.h
nsh.h
p8022.h
page_pool.h net: page_pool: Add bulk support for ptr_ring 2020-11-14 02:29:00 +01:00
pie.h pie: realign comment 2020-03-04 13:25:55 -08:00
ping.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
pkt_cls.h sch_htb: Hierarchical QoS hardware offload 2021-01-22 20:41:29 -08:00
pkt_sched.h net: sched: convert tasklets to use new tasklet_setup() API 2020-11-07 10:41:15 -08:00
pptp.h
protocol.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
psample.h net: sched: take reference to psample group in flow_action infra 2019-09-16 09:18:03 +02:00
psnap.h
raw.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
rawv6.h
red.h net: sched: prevent invalid Scell_log shift count 2020-12-28 14:52:54 -08:00
regulatory.h net/wireless: regulatory.h: drop duplicate word in comment 2020-07-31 09:24:23 +02:00
request_sock.h tcp: bpf: Optionally store mac header in TCP_SAVE_SYN 2020-08-24 14:35:00 -07:00
rose.h
route.h lsm,selinux: pass flowi_common instead of flowi to the LSM hooks 2020-11-23 18:36:21 -05:00
rpl.h net: ipv6: Use struct_size() helper and kcalloc() 2020-06-23 20:27:09 -07:00
rsi_91x.h
rtnetlink.h net: Add extack argument to rtnl_create_link 2018-11-06 15:00:45 -08:00
rtnh.h net: Rename net/nexthop.h net/rtnh.h 2019-04-22 21:47:25 -07:00
sch_generic.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-02-02 14:21:31 -08:00
scm.h fs: Move __scm_install_fd() to __receive_fd() 2020-07-13 11:03:44 -07:00
secure_seq.h
seg6_hmac.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
seg6_local.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
seg6.h seg6: fix seg6_validate_srh() to avoid slab-out-of-bounds 2020-06-04 15:39:32 -07:00
slhc_vj.h
smc.h net/smc: introduce CHID callback for ISM devices 2020-09-28 15:19:03 -07:00
snmp.h net/tls: add skeleton of MIB statistics 2019-10-05 16:29:00 -07:00
sock_reuseport.h net: sock_reuseport: Replace zero-length array with flexible-array member 2020-02-29 21:52:19 -08:00
sock.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-02-16 13:14:06 -08:00
Space.h
stp.h
strparser.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
switchdev.h switchdev: mrp: Extend ring_role_mrp and in_role_mrp 2021-02-16 14:47:46 -08:00
tcp_states.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-02-16 13:14:06 -08:00
timewait_sock.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tipc.h
tls_toe.h net/tls: rename tls_hw_* functions tls_toe_* 2019-10-04 14:07:07 -07:00
tls.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-11-27 18:25:27 -08:00
transp_v6.h tcp: move ipv4_specific to tcp include file 2020-06-23 20:10:15 -07:00
tso.h net: tso: cache transport header length 2020-06-18 20:46:23 -07:00
tun_proto.h
udp_tunnel.h udp: call udp_encap_enable for v6 sockets when enabling encap 2021-02-04 18:37:14 -08:00
udp.h ipv6: move udp declarations to net/udp.h 2021-02-04 18:37:57 -08:00
udplite.h
vsock_addr.h vsock: remove include/linux/vm_sockets.h file 2019-11-14 18:12:17 -08:00
vxlan.h net: sched: only keep the available bits when setting vxlan md->gbp 2020-09-14 16:49:39 -07:00
wext.h
x25.h net/x25: add new state X25_STATE_5 2019-12-09 10:28:43 -08:00
x25device.h
xdp_priv.h page_pool: do not release pool until inflight == 0. 2019-11-16 12:39:10 -08:00
xdp_sock_drv.h xsk: Introduce batched Tx descriptor interfaces 2020-11-17 22:07:40 +01:00
xdp_sock.h xsk: Fix race in SKB mode transmit with shared cq 2020-12-18 16:10:21 +01:00
xdp.h net, veth: Alloc skb in bulk for ndo_xdp_xmit 2021-02-04 01:00:07 +01:00
xfrm.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-10-05 18:40:01 -07:00
xsk_buff_pool.h xsk: Fix race in SKB mode transmit with shared cq 2020-12-18 16:10:21 +01:00