6938 Commits

Author SHA1 Message Date
Niels Dossche
090e73fb9c ipv6: prevent a possible race condition with lifetimes
[ Upstream commit 6c0d8833a605e195ae219b5042577ce52bf71fff ]

valid_lft, prefered_lft and tstamp are always accessed under the lock
"lock" in other places. Reading these without taking the lock may result
in inconsistencies regarding the calculation of the valid and preferred
variables since decisions are taken on these fields for those variables.

Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Niels Dossche <niels.dossche@ugent.be>
Link: https://lore.kernel.org/r/20220223131954.6570-1-niels.dossche@ugent.be
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-16 13:21:47 +01:00
Jiri Bohac
5f53a6a8ae Revert "xfrm: xfrm_state_mtu should return at least 1280 for ipv6"
commit a6d95c5a628a09be129f25d5663a7e9db8261f51 upstream.

This reverts commit b515d2637276a3810d6595e10ab02c13bfd0b63a.

Commit b515d2637276a3810d6595e10ab02c13bfd0b63a ("xfrm: xfrm_state_mtu
should return at least 1280 for ipv6") in v5.14 breaks the TCP MSS
calculation in ipsec transport mode, resulting complete stalls of TCP
connections. This happens when the (P)MTU is 1280 or slighly larger.

The desired formula for the MSS is:
MSS = (MTU - ESP_overhead) - IP header - TCP header

However, the above commit clamps the (MTU - ESP_overhead) to a
minimum of 1280, turning the formula into
MSS = max(MTU - ESP overhead, 1280) -  IP header - TCP header

With the (P)MTU near 1280, the calculated MSS is too large and the
resulting TCP packets never make it to the destination because they
are over the actual PMTU.

The above commit also causes suboptimal double fragmentation in
xfrm tunnel mode, as described in
https://lore.kernel.org/netdev/20210429202529.codhwpc7w6kbudug@dwarf.suse.cz/

The original problem the above commit was trying to fix is now fixed
by commit 6596a0229541270fb8d38d989f91b78838e5e9da ("xfrm: fix MTU
regression").

Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-08 19:07:50 +01:00
Jiri Bohac
ac858e4462 xfrm: fix MTU regression
commit 6596a0229541270fb8d38d989f91b78838e5e9da upstream.

Commit 749439bfac6e1a2932c582e2699f91d329658196 ("ipv6: fix udpv6
sendmsg crash caused by too small MTU") breaks PMTU for xfrm.

A Packet Too Big ICMPv6 message received in response to an ESP
packet will prevent all further communication through the tunnel
if the reported MTU minus the ESP overhead is smaller than 1280.

E.g. in a case of a tunnel-mode ESP with sha256/aes the overhead
is 92 bytes. Receiving a PTB with MTU of 1371 or less will result
in all further packets in the tunnel dropped. A ping through the
tunnel fails with "ping: sendmsg: Invalid argument".

Apparently the MTU on the xfrm route is smaller than 1280 and
fails the check inside ip6_setup_cork() added by 749439bf.

We found this by debugging USGv6/ipv6ready failures. Failing
tests are: "Phase-2 Interoperability Test Scenario IPsec" /
5.3.11 and 5.4.11 (Tunnel Mode: Fragmentation).

Commit b515d2637276a3810d6595e10ab02c13bfd0b63a ("xfrm:
xfrm_state_mtu should return at least 1280 for ipv6") attempted
to fix this but caused another regression in TCP MSS calculations
and had to be reverted.

The patch below fixes the situation by dropping the MTU
check and instead checking for the underflows described in the
749439bf commit message.

Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Fixes: 749439bfac6e ("ipv6: fix udpv6 sendmsg crash caused by too small MTU")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-08 19:07:46 +01:00
Tao Liu
2b3cdd70ea gso: do not skip outer ip header in case of ipip and net_failover
commit cc20cced0598d9a5ff91ae4ab147b3b5e99ee819 upstream.

We encounter a tcp drop issue in our cloud environment. Packet GROed in
host forwards to a VM virtio_net nic with net_failover enabled. VM acts
as a IPVS LB with ipip encapsulation. The full path like:
host gro -> vm virtio_net rx -> net_failover rx -> ipvs fullnat
 -> ipip encap -> net_failover tx -> virtio_net tx

When net_failover transmits a ipip pkt (gso_type = 0x0103, which means
SKB_GSO_TCPV4, SKB_GSO_DODGY and SKB_GSO_IPXIP4), there is no gso
did because it supports TSO and GSO_IPXIP4. But network_header points to
inner ip header.

Call Trace:
 tcp4_gso_segment        ------> return NULL
 inet_gso_segment        ------> inner iph, network_header points to
 ipip_gso_segment
 inet_gso_segment        ------> outer iph
 skb_mac_gso_segment

Afterwards virtio_net transmits the pkt, only inner ip header is modified.
And the outer one just keeps unchanged. The pkt will be dropped in remote
host.

Call Trace:
 inet_gso_segment        ------> inner iph, outer iph is skipped
 skb_mac_gso_segment
 __skb_gso_segment
 validate_xmit_skb
 validate_xmit_skb_list
 sch_direct_xmit
 __qdisc_run
 __dev_queue_xmit        ------> virtio_net
 dev_hard_start_xmit
 __dev_queue_xmit        ------> net_failover
 ip_finish_output2
 ip_output
 iptunnel_xmit
 ip_tunnel_xmit
 ipip_tunnel_xmit        ------> ipip
 dev_hard_start_xmit
 __dev_queue_xmit
 ip_finish_output2
 ip_output
 ip_forward
 ip_rcv
 __netif_receive_skb_one_core
 netif_receive_skb_internal
 napi_gro_receive
 receive_buf
 virtnet_poll
 net_rx_action

The root cause of this issue is specific with the rare combination of
SKB_GSO_DODGY and a tunnel device that adds an SKB_GSO_ tunnel option.
SKB_GSO_DODGY is set from external virtio_net. We need to reset network
header when callbacks.gso_segment() returns NULL.

This patch also includes ipv6_gso_segment(), considering SIT, etc.

Fixes: cb32f511a70b ("ipip: add GSO/TSO support")
Signed-off-by: Tao Liu <thomas.liu@ucloud.cn>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02 11:41:06 +01:00
Eric Dumazet
16dcfde98a ipmr,ip6mr: acquire RTNL before calling ip[6]mr_free_table() on failure path
[ Upstream commit 5611a00697c8ecc5aad04392bea629e9d6a20463 ]

ip[6]mr_free_table() can only be called under RTNL lock.

RTNL: assertion failed at net/core/dev.c (10367)
WARNING: CPU: 1 PID: 5890 at net/core/dev.c:10367 unregister_netdevice_many+0x1246/0x1850 net/core/dev.c:10367
Modules linked in:
CPU: 1 PID: 5890 Comm: syz-executor.2 Not tainted 5.16.0-syzkaller-11627-g422ee58dc0ef #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:unregister_netdevice_many+0x1246/0x1850 net/core/dev.c:10367
Code: 0f 85 9b ee ff ff e8 69 07 4b fa ba 7f 28 00 00 48 c7 c6 00 90 ae 8a 48 c7 c7 40 90 ae 8a c6 05 6d b1 51 06 01 e8 8c 90 d8 01 <0f> 0b e9 70 ee ff ff e8 3e 07 4b fa 4c 89 e7 e8 86 2a 59 fa e9 ee
RSP: 0018:ffffc900046ff6e0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888050f51d00 RSI: ffffffff815fa008 RDI: fffff520008dfece
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815f3d6e R11: 0000000000000000 R12: 00000000fffffff4
R13: dffffc0000000000 R14: ffffc900046ff750 R15: ffff88807b7dc000
FS:  00007f4ab736e700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fee0b4f8990 CR3: 000000001e7d2000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 mroute_clean_tables+0x244/0xb40 net/ipv6/ip6mr.c:1509
 ip6mr_free_table net/ipv6/ip6mr.c:389 [inline]
 ip6mr_rules_init net/ipv6/ip6mr.c:246 [inline]
 ip6mr_net_init net/ipv6/ip6mr.c:1306 [inline]
 ip6mr_net_init+0x3f0/0x4e0 net/ipv6/ip6mr.c:1298
 ops_init+0xaf/0x470 net/core/net_namespace.c:140
 setup_net+0x54f/0xbb0 net/core/net_namespace.c:331
 copy_net_ns+0x318/0x760 net/core/net_namespace.c:475
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178
 copy_process+0x2e0c/0x7300 kernel/fork.c:2167
 kernel_clone+0xe7/0xab0 kernel/fork.c:2555
 __do_sys_clone+0xc8/0x110 kernel/fork.c:2672
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f4ab89f9059
Code: Unable to access opcode bytes at RIP 0x7f4ab89f902f.
RSP: 002b:00007f4ab736e118 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f4ab8b0bf60 RCX: 00007f4ab89f9059
RDX: 0000000020000280 RSI: 0000000020000270 RDI: 0000000040200000
RBP: 00007f4ab8a5308d R08: 0000000020000300 R09: 0000000020000300
R10: 00000000200002c0 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ffc3977cc1f R14: 00007f4ab736e300 R15: 0000000000022000
 </TASK>

Fixes: f243e5a7859a ("ipmr,ip6mr: call ip6mr_free_table() on failure path")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Cong Wang <cong.wang@bytedance.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Link: https://lore.kernel.org/r/20220208053451.2885398-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-02-16 12:52:51 +01:00
Eric Dumazet
cdfaf8e985 ipv6: annotate accesses to fn->fn_sernum
commit aafc2e3285c2d7a79b7ee15221c19fbeca7b1509 upstream.

struct fib6_node's fn_sernum field can be
read while other threads change it.

Add READ_ONCE()/WRITE_ONCE() annotations.

Do not change existing smp barriers in fib6_get_cookie_safe()
and __fib6_update_sernum_upto_root()

syzbot reported:

BUG: KCSAN: data-race in fib6_clean_node / inet6_csk_route_socket

write to 0xffff88813df62e2c of 4 bytes by task 1920 on cpu 1:
 fib6_clean_node+0xc2/0x260 net/ipv6/ip6_fib.c:2178
 fib6_walk_continue+0x38e/0x430 net/ipv6/ip6_fib.c:2112
 fib6_walk net/ipv6/ip6_fib.c:2160 [inline]
 fib6_clean_tree net/ipv6/ip6_fib.c:2240 [inline]
 __fib6_clean_all+0x1a9/0x2e0 net/ipv6/ip6_fib.c:2256
 fib6_flush_trees+0x6c/0x80 net/ipv6/ip6_fib.c:2281
 rt_genid_bump_ipv6 include/net/net_namespace.h:488 [inline]
 addrconf_dad_completed+0x57f/0x870 net/ipv6/addrconf.c:4230
 addrconf_dad_work+0x908/0x1170
 process_one_work+0x3f6/0x960 kernel/workqueue.c:2307
 worker_thread+0x616/0xa70 kernel/workqueue.c:2454
 kthread+0x1bf/0x1e0 kernel/kthread.c:359
 ret_from_fork+0x1f/0x30

read to 0xffff88813df62e2c of 4 bytes by task 15701 on cpu 0:
 fib6_get_cookie_safe include/net/ip6_fib.h:285 [inline]
 rt6_get_cookie include/net/ip6_fib.h:306 [inline]
 ip6_dst_store include/net/ip6_route.h:234 [inline]
 inet6_csk_route_socket+0x352/0x3c0 net/ipv6/inet6_connection_sock.c:109
 inet6_csk_xmit+0x91/0x1e0 net/ipv6/inet6_connection_sock.c:121
 __tcp_transmit_skb+0x1323/0x1840 net/ipv4/tcp_output.c:1402
 tcp_transmit_skb net/ipv4/tcp_output.c:1420 [inline]
 tcp_write_xmit+0x1450/0x4460 net/ipv4/tcp_output.c:2680
 __tcp_push_pending_frames+0x68/0x1c0 net/ipv4/tcp_output.c:2864
 tcp_push+0x2d9/0x2f0 net/ipv4/tcp.c:725
 mptcp_push_release net/mptcp/protocol.c:1491 [inline]
 __mptcp_push_pending+0x46c/0x490 net/mptcp/protocol.c:1578
 mptcp_sendmsg+0x9ec/0xa50 net/mptcp/protocol.c:1764
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:643
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 kernel_sendmsg+0x97/0xd0 net/socket.c:745
 sock_no_sendpage+0x84/0xb0 net/core/sock.c:3086
 inet_sendpage+0x9d/0xc0 net/ipv4/af_inet.c:834
 kernel_sendpage+0x187/0x200 net/socket.c:3492
 sock_sendpage+0x5a/0x70 net/socket.c:1007
 pipe_to_sendpage+0x128/0x160 fs/splice.c:364
 splice_from_pipe_feed fs/splice.c:418 [inline]
 __splice_from_pipe+0x207/0x500 fs/splice.c:562
 splice_from_pipe fs/splice.c:597 [inline]
 generic_splice_sendpage+0x94/0xd0 fs/splice.c:746
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x650 fs/splice.c:891
 do_splice_direct+0x106/0x190 fs/splice.c:979
 do_sendfile+0x675/0xc40 fs/read_write.c:1245
 __do_sys_sendfile64 fs/read_write.c:1310 [inline]
 __se_sys_sendfile64 fs/read_write.c:1296 [inline]
 __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000026f -> 0x00000271

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15701 Comm: syz-executor.2 Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

The Fixes tag I chose is probably arbitrary, I do not think
we need to backport this patch to older kernels.

Fixes: c5cff8561d2d ("ipv6: add rcu grace period before freeing fib6_node")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Link: https://lore.kernel.org/r/20220120174112.1126644-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01 17:24:38 +01:00
Ido Schimmel
20b7af4131 ipv6_tunnel: Rate limit warning messages
commit 6cee105e7f2ced596373951d9ea08dacc3883c68 upstream.

The warning messages can be invoked from the data path for every packet
transmitted through an ip6gre netdev, leading to high CPU utilization.

Fix that by rate limiting the messages.

Fixes: 09c6bbf090ec ("[IPV6]: Do mandatory IPv6 tunnel endpoint checks in realtime")
Reported-by: Maksym Yaremchuk <maksymy@nvidia.com>
Tested-by: Maksym Yaremchuk <maksymy@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-02-01 17:24:36 +01:00
Ghalem Boudour
e895140826 xfrm: fix policy lookup for ipv6 gre packets
commit bcf141b2eb551b3477b24997ebc09c65f117a803 upstream.

On egress side, xfrm lookup is called from __gre6_xmit() with the
fl6_gre_key field not initialized leading to policies selectors check
failure. Consequently, gre packets are sent without encryption.

On ingress side, INET6_PROTO_NOPOLICY was set, thus packets were not
checked against xfrm policies. Like for egress side, fl6_gre_key should be
correctly set, this is now done in decode_session6().

Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Cc: stable@vger.kernel.org
Signed-off-by: Ghalem Boudour <ghalem.boudour@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27 09:19:50 +01:00
William Zhao
0ad45baead ip6_vti: initialize __ip6_tnl_parm struct in vti6_siocdevprivate
[ Upstream commit c1833c3964d5bd8c163bd4e01736a38bc473cb8a ]

The "__ip6_tnl_parm" struct was left uninitialized causing an invalid
load of random data when the "__ip6_tnl_parm" struct was used elsewhere.
As an example, in the function "ip6_tnl_xmit_ctl()", it tries to access
the "collect_md" member. With "__ip6_tnl_parm" being uninitialized and
containing random data, the UBSAN detected that "collect_md" held a
non-boolean value.

The UBSAN issue is as follows:
===============================================================
UBSAN: invalid-load in net/ipv6/ip6_tunnel.c:1025:14
load of value 30 is not a valid value for type '_Bool'
CPU: 1 PID: 228 Comm: kworker/1:3 Not tainted 5.16.0-rc4+ #8
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
<TASK>
dump_stack_lvl+0x44/0x57
ubsan_epilogue+0x5/0x40
__ubsan_handle_load_invalid_value+0x66/0x70
? __cpuhp_setup_state+0x1d3/0x210
ip6_tnl_xmit_ctl.cold.52+0x2c/0x6f [ip6_tunnel]
vti6_tnl_xmit+0x79c/0x1e96 [ip6_vti]
? lock_is_held_type+0xd9/0x130
? vti6_rcv+0x100/0x100 [ip6_vti]
? lock_is_held_type+0xd9/0x130
? rcu_read_lock_bh_held+0xc0/0xc0
? lock_acquired+0x262/0xb10
dev_hard_start_xmit+0x1e6/0x820
__dev_queue_xmit+0x2079/0x3340
? mark_lock.part.52+0xf7/0x1050
? netdev_core_pick_tx+0x290/0x290
? kvm_clock_read+0x14/0x30
? kvm_sched_clock_read+0x5/0x10
? sched_clock_cpu+0x15/0x200
? find_held_lock+0x3a/0x1c0
? lock_release+0x42f/0xc90
? lock_downgrade+0x6b0/0x6b0
? mark_held_locks+0xb7/0x120
? neigh_connected_output+0x31f/0x470
? lockdep_hardirqs_on+0x79/0x100
? neigh_connected_output+0x31f/0x470
? ip6_finish_output2+0x9b0/0x1d90
? rcu_read_lock_bh_held+0x62/0xc0
? ip6_finish_output2+0x9b0/0x1d90
ip6_finish_output2+0x9b0/0x1d90
? ip6_append_data+0x330/0x330
? ip6_mtu+0x166/0x370
? __ip6_finish_output+0x1ad/0xfb0
? nf_hook_slow+0xa6/0x170
ip6_output+0x1fb/0x710
? nf_hook.constprop.32+0x317/0x430
? ip6_finish_output+0x180/0x180
? __ip6_finish_output+0xfb0/0xfb0
? lock_is_held_type+0xd9/0x130
ndisc_send_skb+0xb33/0x1590
? __sk_mem_raise_allocated+0x11cf/0x1560
? dst_output+0x4a0/0x4a0
? ndisc_send_rs+0x432/0x610
addrconf_dad_completed+0x30c/0xbb0
? addrconf_rs_timer+0x650/0x650
? addrconf_dad_work+0x73c/0x10e0
addrconf_dad_work+0x73c/0x10e0
? addrconf_dad_completed+0xbb0/0xbb0
? rcu_read_lock_sched_held+0xaf/0xe0
? rcu_read_lock_bh_held+0xc0/0xc0
process_one_work+0x97b/0x1740
? pwq_dec_nr_in_flight+0x270/0x270
worker_thread+0x87/0xbf0
? process_one_work+0x1740/0x1740
kthread+0x3ac/0x490
? set_kthread_struct+0x100/0x100
ret_from_fork+0x22/0x30
</TASK>
===============================================================

The solution is to initialize "__ip6_tnl_parm" struct to zeros in the
"vti6_siocdevprivate()" function.

Signed-off-by: William Zhao <wizhao@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-11 15:23:33 +01:00
David Ahern
f0e5709824 ipv6: Do cleanup if attribute validation fails in multipath route
[ Upstream commit 95bdba23b5b4aa75fe3e6c84335e638641c707bb ]

As Nicolas noted, if gateway validation fails walking the multipath
attribute the code should jump to the cleanup to free previously
allocated memory.

Fixes: 1ff15a710a86 ("ipv6: Check attribute length for RTA_GATEWAY when deleting multipath route")
Signed-off-by: David Ahern <dsahern@kernel.org>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20220103170555.94638-1-dsahern@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-11 15:23:33 +01:00
David Ahern
c94999cfbb ipv6: Continue processing multipath route even if gateway attribute is invalid
[ Upstream commit e30a845b0376eb51c9c94f56bbd53b2e08ba822f ]

ip6_route_multipath_del loop continues processing the multipath
attribute even if delete of a nexthop path fails. For consistency,
do the same if the gateway attribute is invalid.

Fixes: 1ff15a710a86 ("ipv6: Check attribute length for RTA_GATEWAY when deleting multipath route")
Signed-off-by: David Ahern <dsahern@kernel.org>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20220103171911.94739-1-dsahern@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-11 15:23:33 +01:00
David Ahern
76936ddb49 lwtunnel: Validate RTA_ENCAP_TYPE attribute length
commit 8bda81a4d400cf8a72e554012f0d8c45e07a3904 upstream.

lwtunnel_valid_encap_type_attr is used to validate encap attributes
within a multipath route. Add length validation checking to the type.

lwtunnel_valid_encap_type_attr is called converting attributes to
fib{6,}_config struct which means it is used before fib_get_nhs,
ip6_route_multipath_add, and ip6_route_multipath_del - other
locations that use rtnh_ok and then nla_get_u16 on RTA_ENCAP_TYPE
attribute.

Fixes: 9ed59592e3e3 ("lwtunnel: fix autoload of lwt modules")

Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-11 15:23:32 +01:00
David Ahern
2ebd777513 ipv6: Check attribute length for RTA_GATEWAY when deleting multipath route
commit 1ff15a710a862db1101b97810af14aedc835a86a upstream.

Make sure RTA_GATEWAY for IPv6 multipath route has enough bytes to hold
an IPv6 address.

Fixes: 6b9ea5a64ed5 ("ipv6: fix multipath route replace error recovery")
Signed-off-by: David Ahern <dsahern@kernel.org>
Cc: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-11 15:23:32 +01:00
David Ahern
a02d2be7eb ipv6: Check attribute length for RTA_GATEWAY in multipath route
commit 4619bcf91399f00a40885100fb61d594d8454033 upstream.

Commit referenced in the Fixes tag used nla_memcpy for RTA_GATEWAY as
does the current nla_get_in6_addr. nla_memcpy protects against accessing
memory greater than what is in the attribute, but there is no check
requiring the attribute to have an IPv6 address. Add it.

Fixes: 51ebd3181572 ("ipv6: add support of equal cost multipath (ECMP)")
Signed-off-by: David Ahern <dsahern@kernel.org>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-11 15:23:32 +01:00
Coco Li
0a2e9f6a8f udp: using datalen to cap ipv6 udp max gso segments
[ Upstream commit 736ef37fd9a44f5966e25319d08ff7ea99ac79e8 ]

The max number of UDP gso segments is intended to cap to
UDP_MAX_SEGMENTS, this is checked in udp_send_skb().

skb->len contains network and transport header len here, we should use
only data len instead.

This is the ipv6 counterpart to the below referenced commit,
which missed the ipv6 change

Fixes: 158390e45612 ("udp: using datalen to cap max gso segments")
Signed-off-by: Coco Li <lixiaoyan@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20211223222441.2975883-1-lixiaoyan@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-05 12:37:44 +01:00
Eric Dumazet
ad0ed314d6 sit: do not call ipip6_dev_free() from sit_init_net()
[ Upstream commit e28587cc491ef0f3c51258fdc87fbc386b1d4c59 ]

ipip6_dev_free is sit dev->priv_destructor, already called
by register_netdevice() if something goes wrong.

Alternative would be to make ipip6_dev_free() robust against
multiple invocations, but other drivers do not implement this
strategy.

syzbot reported:

dst_release underflow
WARNING: CPU: 0 PID: 5059 at net/core/dst.c:173 dst_release+0xd8/0xe0 net/core/dst.c:173
Modules linked in:
CPU: 1 PID: 5059 Comm: syz-executor.4 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:dst_release+0xd8/0xe0 net/core/dst.c:173
Code: 4c 89 f2 89 d9 31 c0 5b 41 5e 5d e9 da d5 44 f9 e8 1d 90 5f f9 c6 05 87 48 c6 05 01 48 c7 c7 80 44 99 8b 31 c0 e8 e8 67 29 f9 <0f> 0b eb 85 0f 1f 40 00 53 48 89 fb e8 f7 8f 5f f9 48 83 c3 a8 48
RSP: 0018:ffffc9000aa5faa0 EFLAGS: 00010246
RAX: d6894a925dd15a00 RBX: 00000000ffffffff RCX: 0000000000040000
RDX: ffffc90005e19000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: 0000000000000000 R08: ffffffff816a1f42 R09: ffffed1017344f2c
R10: ffffed1017344f2c R11: 0000000000000000 R12: 0000607f462b1358
R13: 1ffffffff1bfd305 R14: ffffe8ffffcb1358 R15: dffffc0000000000
FS:  00007f66c71a2700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f88aaed5058 CR3: 0000000023e0f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 dst_cache_destroy+0x107/0x1e0 net/core/dst_cache.c:160
 ipip6_dev_free net/ipv6/sit.c:1414 [inline]
 sit_init_net+0x229/0x550 net/ipv6/sit.c:1936
 ops_init+0x313/0x430 net/core/net_namespace.c:140
 setup_net+0x35b/0x9d0 net/core/net_namespace.c:326
 copy_net_ns+0x359/0x5c0 net/core/net_namespace.c:470
 create_new_namespaces+0x4ce/0xa00 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x11e/0x180 kernel/nsproxy.c:226
 ksys_unshare+0x57d/0xb50 kernel/fork.c:3075
 __do_sys_unshare kernel/fork.c:3146 [inline]
 __se_sys_unshare kernel/fork.c:3144 [inline]
 __x64_sys_unshare+0x34/0x40 kernel/fork.c:3144
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f66c882ce99
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f66c71a2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f66c893ff60 RCX: 00007f66c882ce99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000048040200
RBP: 00007f66c8886ff1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff6634832f R14: 00007f66c71a2300 R15: 0000000000022000
 </TASK>

Fixes: cf124db566e6 ("net: Fix inconsistent teardown and release of private netdev state.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Link: https://lore.kernel.org/r/20211216111741.1387540-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-22 09:29:38 +01:00
Andrea Mayer
ef8804e47c seg6: fix the iif in the IPv6 socket control block
commit ae68d93354e5bf5191ee673982251864ea24dd5c upstream.

When an IPv4 packet is received, the ip_rcv_core(...) sets the receiving
interface index into the IPv4 socket control block (v5.16-rc4,
net/ipv4/ip_input.c line 510):

    IPCB(skb)->iif = skb->skb_iif;

If that IPv4 packet is meant to be encapsulated in an outer IPv6+SRH
header, the seg6_do_srh_encap(...) performs the required encapsulation.
In this case, the seg6_do_srh_encap function clears the IPv6 socket control
block (v5.16-rc4 net/ipv6/seg6_iptunnel.c line 163):

    memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));

The memset(...) was introduced in commit ef489749aae5 ("ipv6: sr: clear
IP6CB(skb) on SRH ip4ip6 encapsulation") a long time ago (2019-01-29).

Since the IPv6 socket control block and the IPv4 socket control block share
the same memory area (skb->cb), the receiving interface index info is lost
(IP6CB(skb)->iif is set to zero).

As a side effect, that condition triggers a NULL pointer dereference if
commit 0857d6f8c759 ("ipv6: When forwarding count rx stats on the orig
netdev") is applied.

To fix that issue, we set the IP6CB(skb)->iif with the index of the
receiving interface once again.

Fixes: ef489749aae5 ("ipv6: sr: clear IP6CB(skb) on SRH ip4ip6 encapsulation")
Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20211208195409.12169-1-andrea.mayer@uniroma2.it
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 14:49:00 +01:00
msizanoen1
ee38eb8cf9 ipv6: fix memory leak in fib6_rule_suppress
commit cdef485217d30382f3bf6448c54b4401648fe3f1 upstream.

The kernel leaks memory when a `fib` rule is present in IPv6 nftables
firewall rules and a suppress_prefix rule is present in the IPv6 routing
rules (used by certain tools such as wg-quick). In such scenarios, every
incoming packet will leak an allocation in `ip6_dst_cache` slab cache.

After some hours of `bpftrace`-ing and source code reading, I tracked
down the issue to ca7a03c41753 ("ipv6: do not free rt if
FIB_LOOKUP_NOREF is set on suppress rule").

The problem with that change is that the generic `args->flags` always have
`FIB_LOOKUP_NOREF` set[1][2] but the IPv6-specific flag
`RT6_LOOKUP_F_DST_NOREF` might not be, leading to `fib6_rule_suppress` not
decreasing the refcount when needed.

How to reproduce:
 - Add the following nftables rule to a prerouting chain:
     meta nfproto ipv6 fib saddr . mark . iif oif missing drop
   This can be done with:
     sudo nft create table inet test
     sudo nft create chain inet test test_chain '{ type filter hook prerouting priority filter + 10; policy accept; }'
     sudo nft add rule inet test test_chain meta nfproto ipv6 fib saddr . mark . iif oif missing drop
 - Run:
     sudo ip -6 rule add table main suppress_prefixlength 0
 - Watch `sudo slabtop -o | grep ip6_dst_cache` to see memory usage increase
   with every incoming ipv6 packet.

This patch exposes the protocol-specific flags to the protocol
specific `suppress` function, and check the protocol-specific `flags`
argument for RT6_LOOKUP_F_DST_NOREF instead of the generic
FIB_LOOKUP_NOREF when decreasing the refcount, like this.

[1]: ca7a03c417/net/ipv6/fib6_rules.c (L71)
[2]: ca7a03c417/net/ipv6/fib6_rules.c (L99)

Link: https://bugzilla.kernel.org/show_bug.cgi?id=215105
Fixes: ca7a03c41753 ("ipv6: do not free rt if FIB_LOOKUP_NOREF is set on suppress rule")
Cc: stable@vger.kernel.org
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08 09:01:13 +01:00
Nikolay Aleksandrov
cca61bb170 net: ipv6: add fib6_nh_release_dsts stub
[ Upstream commit 8837cbbf854246f5f4d565f21e6baa945d37aded ]

We need a way to release a fib6_nh's per-cpu dsts when replacing
nexthops otherwise we can end up with stale per-cpu dsts which hold net
device references, so add a new IPv6 stub called fib6_nh_release_dsts.
It must be used after an RCU grace period, so no new dsts can be created
through a group's nexthop entry.
Similar to fib6_nh_release it shouldn't be used if fib6_nh_init has failed
so it doesn't need a dummy stub when IPv6 is not enabled.

Fixes: 7bf4796dd099 ("nexthops: add support for replace")
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01 09:23:33 +01:00
Eric Dumazet
b638eb32c6 ipv6: fix typos in __ip6_finish_output()
[ Upstream commit 19d36c5f294879949c9d6f57cb61d39cc4c48553 ]

We deal with IPv6 packets, so we need to use IP6CB(skb)->flags and
IP6SKB_REROUTED, instead of IPCB(skb)->flags and IPSKB_REROUTED

Found by code inspection, please double check that fixing this bug
does not surface other bugs.

Fixes: 09ee9dba9611 ("ipv6: Reinject IPv6 packets if IPsec policy matches after SNAT")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tobias Brunner <tobias@strongswan.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: David Ahern <dsahern@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Tested-by: Tobias Brunner <tobias@strongswan.org>
Acked-by: Tobias Brunner <tobias@strongswan.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01 09:23:32 +01:00
Jakub Kicinski
a91c8ee2ed udp6: allow SO_MARK ctrl msg to affect routing
[ Upstream commit 42dcfd850e514b229d616a53dec06d0f2533217c ]

Commit c6af0c227a22 ("ip: support SO_MARK cmsg")
added propagation of SO_MARK from cmsg to skb->mark.
For IPv4 and raw sockets the mark also affects route
lookup, but in case of IPv6 the flow info is
initialized before cmsg is parsed.

Fixes: c6af0c227a22 ("ip: support SO_MARK cmsg")
Reported-and-tested-by: Xintong Hu <huxintong@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-17 09:48:40 +01:00
Stephen Suryaputra
d99f320a1b gre/sit: Don't generate link-local addr if addr_gen_mode is IN6_ADDR_GEN_MODE_NONE
[ Upstream commit 61e18ce7348bfefb5688a8bcd4b4d6b37c0f9b2a ]

When addr_gen_mode is set to IN6_ADDR_GEN_MODE_NONE, the link-local addr
should not be generated. But it isn't the case for GRE (as well as GRE6)
and SIT tunnels. Make it so that tunnels consider the addr_gen_mode,
especially for IN6_ADDR_GEN_MODE_NONE.

Do this in add_v4_addrs() to cover both GRE and SIT only if the addr
scope is link.

Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Acked-by: Antonio Quartulli <a@unstable.cc>
Link: https://lore.kernel.org/r/20211020200618.467342-1-ssuryaextr@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-17 09:48:32 +01:00
Eric Dumazet
3f439c231a ipv6: use siphash in rt6_exception_hash()
commit 4785305c05b25a242e5314cc821f54ade4c18810 upstream.

A group of security researchers brought to our attention
the weakness of hash function used in rt6_exception_hash()

Lets use siphash instead of Jenkins Hash, to considerably
reduce security risks.

Following patch deals with IPv4.

Fixes: 35732d01fe31 ("ipv6: introduce a hash table to store dst cache")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Cc: Wei Wang <weiwan@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Acked-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[OP: adjusted context for 5.4 stable]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-02 19:46:11 +01:00
Jeremy Sowden
8c6680025b netfilter: ip6_tables: zero-initialize fragment offset
[ Upstream commit 310e2d43c3ad429c1fba4b175806cf1f55ed73a6 ]

ip6tables only sets the `IP6T_F_PROTO` flag on a rule if a protocol is
specified (`-p tcp`, for example).  However, if the flag is not set,
`ip6_packet_match` doesn't call `ipv6_find_hdr` for the skb, in which
case the fragment offset is left uninitialized and a garbage value is
passed to each matcher.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-17 10:42:33 +02:00
Mike Manning
b723b34a98 net: prefer socket bound to interface when not in VRF
[ Upstream commit 8d6c414cd2fb74aa6812e9bfec6178f8246c4f3a ]

The commit 6da5b0f027a8 ("net: ensure unbound datagram socket to be
chosen when not in a VRF") modified compute_score() so that a device
match is always made, not just in the case of an l3mdev skb, then
increments the score also for unbound sockets. This ensures that
sockets bound to an l3mdev are never selected when not in a VRF.
But as unbound and bound sockets are now scored equally, this results
in the last opened socket being selected if there are matches in the
default VRF for an unbound socket and a socket bound to a dev that is
not an l3mdev. However, handling prior to this commit was to always
select the bound socket in this case. Reinstate this handling by
incrementing the score only for bound sockets. The required isolation
due to choosing between an unbound socket and a socket bound to an
l3mdev remains in place due to the device match always being made.
The same approach is taken for compute_score() for stream sockets.

Fixes: 6da5b0f027a8 ("net: ensure unbound datagram socket to be chosen when not in a VRF")
Fixes: e78190581aff ("net: ensure unbound stream socket to be chosen when not in a VRF")
Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/cf0a8523-b362-1edf-ee78-eef63cbbb428@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-13 10:08:20 +02:00
Eric Dumazet
f8ffde0bb9 net: udp: annotate data race around udp_sk(sk)->corkflag
commit a9f5970767d11eadc805d5283f202612c7ba1f59 upstream.

up->corkflag field can be read or written without any lock.
Annotate accesses to avoid possible syzbot/KCSAN reports.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06 15:42:37 +02:00
Xiao Liang
a2624e0934 net: ipv4: Fix rtnexthop len when RTA_FLOW is present
[ Upstream commit 597aa16c782496bf74c5dc3b45ff472ade6cee64 ]

Multipath RTA_FLOW is embedded in nexthop. Dump it in fib_add_nexthop()
to get the length of rtnexthop correct.

Fixes: b0f60193632e ("ipv4: Refactor nexthop attributes in fib_dump_info")
Signed-off-by: Xiao Liang <shaw.leon@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-06 15:42:33 +02:00
zhang kai
7273cb182f ipv6: delay fib6_sernum increase in fib6_add
[ Upstream commit e87b5052271e39d62337ade531992b7e5d8c2cfa ]

only increase fib6_sernum in net namespace after add fib6_info
successfully.

Signed-off-by: zhang kai <zhangkaiheb@126.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30 10:09:24 +02:00
Benjamin Hesmans
d448b240b1 netfilter: socket: icmp6: fix use-after-scope
[ Upstream commit 730affed24bffcd1eebd5903171960f5ff9f1f22 ]

Bug reported by KASAN:

BUG: KASAN: use-after-scope in inet6_ehashfn (net/ipv6/inet6_hashtables.c:40)
Call Trace:
(...)
inet6_ehashfn (net/ipv6/inet6_hashtables.c:40)
(...)
nf_sk_lookup_slow_v6 (net/ipv6/netfilter/nf_socket_ipv6.c:91
net/ipv6/netfilter/nf_socket_ipv6.c:146)

It seems that this bug has already been fixed by Eric Dumazet in the
past in:
commit 78296c97ca1f ("netfilter: xt_socket: fix a stack corruption bug")

But a variant of the same issue has been introduced in
commit d64d80a2cde9 ("netfilter: x_tables: don't extract flow keys on early demuxed sks in socket match")

`daddr` and `saddr` potentially hold a reference to ipv6_var that is no
longer in scope when the call to `nf_socket_get_sock_v6` is made.

Fixes: d64d80a2cde9 ("netfilter: x_tables: don't extract flow keys on early demuxed sks in socket match")
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Benjamin Hesmans <benjamin.hesmans@tessares.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-22 12:26:45 +02:00
Eric Dumazet
f73cbdd1b8 ipv6: make exception cache less predictible
[ Upstream commit a00df2caffed3883c341d5685f830434312e4a43 ]

Even after commit 4785305c05b2 ("ipv6: use siphash in rt6_exception_hash()"),
an attacker can still use brute force to learn some secrets from a victim
linux host.

One way to defeat these attacks is to make the max depth of the hash
table bucket a random value.

Before this patch, each bucket of the hash table used to store exceptions
could contain 6 items under attack.

After the patch, each bucket would contains a random number of items,
between 6 and 10. The attacker can no longer infer secrets.

This is slightly increasing memory size used by the hash table,
we do not expect this to be a problem.

Following patch is dealing with the same issue in IPv4.

Fixes: 35732d01fe31 ("ipv6: introduce a hash table to store dst cache")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Cc: Wei Wang <weiwan@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15 09:47:37 +02:00
Vasily Averin
ebb1b38be0 ipv6: ip6_finish_output2: set sk into newly allocated nskb
[ Upstream commit 2d85a1b31dde84038ea07ad825c3d8d3e71f4344 ]

skb_set_owner_w() should set sk not to old skb but to new nskb.

Fixes: 5796015fa968 ("ipv6: allocate enough headroom in ip6_finish_output2()")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Link: https://lore.kernel.org/r/70c0744f-89ae-1869-7e3e-4fa292158f4b@virtuozzo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-31 08:19:39 +02:00
Vasily Averin
ded37d0344 ipv6: allocate enough headroom in ip6_finish_output2()
[ Upstream commit 5796015fa968a3349027a27dcd04c71d95c53ba5 ]

When TEE target mirrors traffic to another interface, sk_buff may
not have enough headroom to be processed correctly.
ip_finish_output2() detect this situation for ipv4 and allocates
new skb with enogh headroom. However ipv6 lacks this logic in
ip_finish_output2 and it leads to skb_under_panic:

 skbuff: skb_under_panic: text:ffffffffc0866ad4 len:96 put:24
 head:ffff97be85e31800 data:ffff97be85e317f8 tail:0x58 end:0xc0 dev:gre0
 ------------[ cut here ]------------
 kernel BUG at net/core/skbuff.c:110!
 invalid opcode: 0000 [#1] SMP PTI
 CPU: 2 PID: 393 Comm: kworker/2:2 Tainted: G           OE     5.13.0 #13
 Hardware name: Virtuozzo KVM, BIOS 1.11.0-2.vz7.4 04/01/2014
 Workqueue: ipv6_addrconf addrconf_dad_work
 RIP: 0010:skb_panic+0x48/0x4a
 Call Trace:
  skb_push.cold.111+0x10/0x10
  ipgre_header+0x24/0xf0 [ip_gre]
  neigh_connected_output+0xae/0xf0
  ip6_finish_output2+0x1a8/0x5a0
  ip6_output+0x5c/0x110
  nf_dup_ipv6+0x158/0x1000 [nf_dup_ipv6]
  tee_tg6+0x2e/0x40 [xt_TEE]
  ip6t_do_table+0x294/0x470 [ip6_tables]
  nf_hook_slow+0x44/0xc0
  nf_hook.constprop.34+0x72/0xe0
  ndisc_send_skb+0x20d/0x2e0
  ndisc_send_ns+0xd1/0x210
  addrconf_dad_work+0x3c8/0x540
  process_one_work+0x1d1/0x370
  worker_thread+0x30/0x390
  kthread+0x116/0x130
  ret_from_fork+0x22/0x30

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-31 08:19:38 +02:00
Paolo Abeni
8302513614 ipv6: fix another slab-out-of-bounds in fib6_nh_flush_exceptions
[ Upstream commit 8fb4792f091e608a0a1d353dfdf07ef55a719db5 ]

While running the self-tests on a KASAN enabled kernel, I observed a
slab-out-of-bounds splat very similar to the one reported in
commit 821bbf79fe46 ("ipv6: Fix KASAN: slab-out-of-bounds Read in
 fib6_nh_flush_exceptions").

We additionally need to take care of fib6_metrics initialization
failure when the caller provides an nh.

The fix is similar, explicitly free the route instead of calling
fib6_info_release on a half-initialized object.

Fixes: f88d8ea67fbdb ("ipv6: Plumb support for nexthop object in a fib6_info")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28 13:30:57 +02:00
Nicolas Dichtel
7f4848229e ipv6: fix 'disable_policy' for fwd packets
[ Upstream commit ccd27f05ae7b8ebc40af5b004e94517a919aa862 ]

The goal of commit df789fe75206 ("ipv6: Provide ipv6 version of
"disable_policy" sysctl") was to have the disable_policy from ipv4
available on ipv6.
However, it's not exactly the same mechanism. On IPv4, all packets coming
from an interface, which has disable_policy set, bypass the policy check.
For ipv6, this is done only for local packets, ie for packets destinated to
an address configured on the incoming interface.

Let's align ipv6 with ipv4 so that the 'disable_policy' sysctl has the same
effect for both protocols.

My first approach was to create a new kind of route cache entries, to be
able to set DST_NOPOLICY without modifying routes. This would have added a
lot of code. Because the local delivery path is already handled, I choose
to focus on the forwarding path to minimize code churn.

Fixes: df789fe75206 ("ipv6: Provide ipv6 version of "disable_policy" sysctl")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28 13:30:53 +02:00
Eric Dumazet
d2f7b384a7 udp: annotate data races around unix_sk(sk)->gso_size
commit 18a419bad63b7f68a1979e28459782518e7b6bbe upstream.

Accesses to unix_sk(sk)->gso_size are lockless.
Add READ_ONCE()/WRITE_ONCE() around them.

BUG: KCSAN: data-race in udp_lib_setsockopt / udpv6_sendmsg

write to 0xffff88812d78f47c of 2 bytes by task 10849 on cpu 1:
 udp_lib_setsockopt+0x3b3/0x710 net/ipv4/udp.c:2696
 udpv6_setsockopt+0x63/0x90 net/ipv6/udp.c:1630
 sock_common_setsockopt+0x5d/0x70 net/core/sock.c:3265
 __sys_setsockopt+0x18f/0x200 net/socket.c:2104
 __do_sys_setsockopt net/socket.c:2115 [inline]
 __se_sys_setsockopt net/socket.c:2112 [inline]
 __x64_sys_setsockopt+0x62/0x70 net/socket.c:2112
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88812d78f47c of 2 bytes by task 10852 on cpu 0:
 udpv6_sendmsg+0x161/0x16b0 net/ipv6/udp.c:1299
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:642
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2337
 ___sys_sendmsg net/socket.c:2391 [inline]
 __sys_sendmmsg+0x315/0x4b0 net/socket.c:2477
 __do_sys_sendmmsg net/socket.c:2506 [inline]
 __se_sys_sendmmsg net/socket.c:2503 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2503
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000 -> 0x0005

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10852 Comm: syz-executor.0 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-25 14:35:15 +02:00
Eric Dumazet
84ed834094 ipv6: tcp: drop silly ICMPv6 packet too big messages
commit c7bb4b89033b764eb07db4e060548a6311d801ee upstream.

While TCP stack scales reasonably well, there is still one part that
can be used to DDOS it.

IPv6 Packet too big messages have to lookup/insert a new route,
and if abused by attackers, can easily put hosts under high stress,
with many cpus contending on a spinlock while one is stuck in fib6_run_gc()

ip6_protocol_deliver_rcu()
 icmpv6_rcv()
  icmpv6_notify()
   tcp_v6_err()
    tcp_v6_mtu_reduced()
     inet6_csk_update_pmtu()
      ip6_rt_update_pmtu()
       __ip6_rt_update_pmtu()
        ip6_rt_cache_alloc()
         ip6_dst_alloc()
          dst_alloc()
           ip6_dst_gc()
            fib6_run_gc()
             spin_lock_bh() ...

Some of our servers have been hit by malicious ICMPv6 packets
trying to _increase_ the MTU/MSS of TCP flows.

We believe these ICMPv6 packets are a result of a bug in one ISP stack,
since they were blindly sent back for _every_ (small) packet sent to them.

These packets are for one TCP flow:
09:24:36.266491 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.266509 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.316688 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.316704 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.608151 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240

TCP stack can filter some silly requests :

1) MTU below IPV6_MIN_MTU can be filtered early in tcp_v6_err()
2) tcp_v6_mtu_reduced() can drop requests trying to increase current MSS.

This tests happen before the IPv6 routing stack is entered, thus
removing the potential contention and route exhaustion.

Note that IPv6 stack was performing these checks, but too late
(ie : after the route has been added, and after the potential
garbage collect war)

v2: fix typo caught by Martin, thanks !
v3: exports tcp_mtu_to_mss(), caught by David, thanks !

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-25 14:35:15 +02:00
Eric Dumazet
315033cab3 tcp: annotate data races around tp->mtu_info
commit 561022acb1ce62e50f7a8258687a21b84282a4cb upstream.

While tp->mtu_info is read while socket is owned, the write
sides happen from err handlers (tcp_v[46]_mtu_reduced)
which only own the socket spinlock.

Fixes: 563d34d05786 ("tcp: dont drop MTU reduction indications")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-25 14:35:15 +02:00
Alexander Ovechkin
8cff7b28ab net: send SYNACK packet with accepted fwmark
commit 43b90bfad34bcb81b8a5bc7dc650800f4be1787e upstream.

commit e05a90ec9e16 ("net: reflect mark on tcp syn ack packets")
fixed IPv4 only.

This part is for the IPv6 side.

Fixes: e05a90ec9e16 ("net: reflect mark on tcp syn ack packets")
Signed-off-by: Alexander Ovechkin <ovov@yandex-team.ru>
Acked-by: Dmitry Yakunin <zeil@yandex-team.ru>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-25 14:35:15 +02:00
Vadim Fedorenko
c6f4a71153 net: ipv6: fix return value of ip6_skb_dst_mtu
commit 40fc3054b45820c28ea3c65e2c86d041dc244a8a upstream.

Commit 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE") introduced
ip6_skb_dst_mtu with return value of signed int which is inconsistent
with actually returned values. Also 2 users of this function actually
assign its value to unsigned int variable and only __xfrm6_output
assigns result of this function to signed variable but actually uses
as unsigned in further comparisons and calls. Change this function
to return unsigned int value.

Fixes: 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE")
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-25 14:35:14 +02:00
Jakub Kicinski
d27483b844 net: ip: avoid OOM kills with large UDP sends over loopback
[ Upstream commit 6d123b81ac615072a8525c13c6c41b695270a15d ]

Dave observed number of machines hitting OOM on the UDP send
path. The workload seems to be sending large UDP packets over
loopback. Since loopback has MTU of 64k kernel will try to
allocate an skb with up to 64k of head space. This has a good
chance of failing under memory pressure. What's worse if
the message length is <32k the allocation may trigger an
OOM killer.

This is entirely avoidable, we can use an skb with page frags.

af_unix solves a similar problem by limiting the head
length to SKB_MAX_ALLOC. This seems like a good and simple
approach. It means that UDP messages > 16kB will now
use fragments if underlying device supports SG, if extra
allocator pressure causes regressions in real workloads
we can switch to trying the large allocation first and
falling back.

v4: pre-calculate all the additions to alloclen so
    we can be sure it won't go over order-2

Reported-by: Dave Jones <dsj@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-19 08:53:13 +02:00
Willy Tarreau
ccde03a6a0 ipv6: use prandom_u32() for ID generation
[ Upstream commit 62f20e068ccc50d6ab66fdb72ba90da2b9418c99 ]

This is a complement to commit aa6dd211e4b1 ("inet: use bigger hash
table for IP ID generation"), but focusing on some specific aspects
of IPv6.

Contary to IPv4, IPv6 only uses packet IDs with fragments, and with a
minimum MTU of 1280, it's much less easy to force a remote peer to
produce many fragments to explore its ID sequence. In addition packet
IDs are 32-bit in IPv6, which further complicates their analysis. On
the other hand, it is often easier to choose among plenty of possible
source addresses and partially work around the bigger hash table the
commit above permits, which leaves IPv6 partially exposed to some
possibilities of remote analysis at the risk of weakening some
protocols like DNS if some IDs can be predicted with a good enough
probability.

Given the wide range of permitted IDs, the risk of collision is extremely
low so there's no need to rely on the positive increment algorithm that
is shared with the IPv4 code via ip_idents_reserve(). We have a fast
PRNG, so let's simply call prandom_u32() and be done with it.

Performance measurements at 10 Gbps couldn't show any difference with
the previous code, even when using a single core, because due to the
large fragments, we're limited to only ~930 kpps at 10 Gbps and the cost
of the random generation is completely offset by other operations and by
the network transfer time. In addition, this change removes the need to
update a shared entry in the idents table so it may even end up being
slightly faster on large scale systems where this matters.

The risk of at least one collision here is about 1/80 million among
10 IDs, 1/850k among 100 IDs, and still only 1/8.5k among 1000 IDs,
which remains very low compared to IPv4 where all IDs are reused
every 4 to 80ms on a 10 Gbps flow depending on packet sizes.

Reported-by: Amit Klein <aksecurity@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20210529110746.6796-1-w@1wt.eu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-19 08:53:09 +02:00
Eric Dumazet
48fa874498 ipv6: fix out-of-bound access in ip6_parse_tlv()
[ Upstream commit 624085a31c1ad6a80b1e53f686bf6ee92abbf6e8 ]

First problem is that optlen is fetched without checking
there is more than one byte to parse.

Fix this by taking care of IPV6_TLV_PAD1 before
fetching optlen (under appropriate sanity checks against len)

Second problem is that IPV6_TLV_PADN checks of zero
padding are performed before the check of remaining length.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Fixes: c1412fce7ecc ("net/ipv6/exthdrs.c: Strict PadN option checking")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:53:33 +02:00
Eric Dumazet
bc54d98bd2 ipv6: exthdrs: do not blindly use init_net
[ Upstream commit bcc3f2a829b9edbe3da5fb117ee5a63686d31834 ]

I see no reason why max_dst_opts_cnt and max_hbh_opts_cnt
are fetched from the initial net namespace.

The other sysctls (max_dst_opts_len & max_hbh_opts_len)
are in fact already using the current ns.

Note: it is not clear why ipv6_destopt_rcv() use two ways to
get to the netns :

 1) dev_net(dst->dev)
    Originally used to increment IPSTATS_MIB_INHDRERRORS

 2) dev_net(skb->dev)
     Tom used this variant in his patch.

Maybe this calls to use ipv6_skb_net() instead ?

Fixes: 47d3d7ac656a ("ipv6: Implement limits on Hop-by-Hop and Destination options")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@quantonium.net>
Cc: Coco Li <lixiaoyan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:53:32 +02:00
Sabrina Dubroca
08a7306e11 xfrm: xfrm_state_mtu should return at least 1280 for ipv6
[ Upstream commit b515d2637276a3810d6595e10ab02c13bfd0b63a ]

Jianwen reported that IPv6 Interoperability tests are failing in an
IPsec case where one of the links between the IPsec peers has an MTU
of 1280. The peer generates a packet larger than this MTU, the router
replies with a "Packet too big" message indicating an MTU of 1280.
When the peer tries to send another large packet, xfrm_state_mtu
returns 1280 - ipsec_overhead, which causes ip6_setup_cork to fail
with EINVAL.

We can fix this by forcing xfrm_state_mtu to return IPV6_MIN_MTU when
IPv6 is used. After going through IPsec, the packet will then be
fragmented to obey the actual network's PMTU, just before leaving the
host.

Currently, TFC padding is capped to PMTU - overhead to avoid
fragementation: after padding and encapsulation, we still fit within
the PMTU. That behavior is preserved in this patch.

Fixes: 91657eafb64b ("xfrm: take net hdr len into account for esp payload size calculation")
Reported-by: Jianwen Ji <jiji@redhat.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:53:26 +02:00
Zheng Yongjun
eb2b1216bc net: ipv4: Remove unneed BUG() function
[ Upstream commit 5ac6b198d7e312bd10ebe7d58c64690dc59cc49a ]

When 'nla_parse_nested_deprecated' failed, it's no need to
BUG() here, return -EINVAL is ok.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-30 08:47:46 -04:00
Paolo Abeni
5a88477c1c udp: fix race between close() and udp_abort()
[ Upstream commit a8b897c7bcd47f4147d066e22cc01d1026d7640e ]

Kaustubh reported and diagnosed a panic in udp_lib_lookup().
The root cause is udp_abort() racing with close(). Both
racing functions acquire the socket lock, but udp{v6}_destroy_sock()
release it before performing destructive actions.

We can't easily extend the socket lock scope to avoid the race,
instead use the SOCK_DEAD flag to prevent udp_abort from doing
any action when the critical race happens.

Diagnosed-and-tested-by: Kaustubh Pandey <kapandey@codeaurora.org>
Fixes: 5d77dca82839 ("net: diag: support SOCK_DESTROY for UDP sockets")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-23 14:41:24 +02:00
Coco Li
7ba7fa78a9 ipv6: Fix KASAN: slab-out-of-bounds Read in fib6_nh_flush_exceptions
[ Upstream commit 821bbf79fe46a8b1d18aa456e8ed0a3c208c3754 ]

Reported by syzbot:
HEAD commit:    90c911ad Merge tag 'fixes' of git://git.kernel.org/pub/scm..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
dashboard link: https://syzkaller.appspot.com/bug?extid=123aa35098fd3c000eb7
compiler:       Debian clang version 11.0.1-2

==================================================================
BUG: KASAN: slab-out-of-bounds in fib6_nh_get_excptn_bucket net/ipv6/route.c:1604 [inline]
BUG: KASAN: slab-out-of-bounds in fib6_nh_flush_exceptions+0xbd/0x360 net/ipv6/route.c:1732
Read of size 8 at addr ffff8880145c78f8 by task syz-executor.4/17760

CPU: 0 PID: 17760 Comm: syz-executor.4 Not tainted 5.12.0-rc8-syzkaller #0
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x202/0x31e lib/dump_stack.c:120
 print_address_description+0x5f/0x3b0 mm/kasan/report.c:232
 __kasan_report mm/kasan/report.c:399 [inline]
 kasan_report+0x15c/0x200 mm/kasan/report.c:416
 fib6_nh_get_excptn_bucket net/ipv6/route.c:1604 [inline]
 fib6_nh_flush_exceptions+0xbd/0x360 net/ipv6/route.c:1732
 fib6_nh_release+0x9a/0x430 net/ipv6/route.c:3536
 fib6_info_destroy_rcu+0xcb/0x1c0 net/ipv6/ip6_fib.c:174
 rcu_do_batch kernel/rcu/tree.c:2559 [inline]
 rcu_core+0x8f6/0x1450 kernel/rcu/tree.c:2794
 __do_softirq+0x372/0x7a6 kernel/softirq.c:345
 invoke_softirq kernel/softirq.c:221 [inline]
 __irq_exit_rcu+0x22c/0x260 kernel/softirq.c:422
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:434
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:lock_acquire+0x1f6/0x720 kernel/locking/lockdep.c:5515
Code: f6 84 24 a1 00 00 00 02 0f 85 8d 02 00 00 f7 c3 00 02 00 00 49 bd 00 00 00 00 00 fc ff df 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 4b c7 44 3d 09 00 00 00 00 43 c7 44 3d
RSP: 0018:ffffc90009e06560 EFLAGS: 00000206
RAX: 1ffff920013c0cc0 RBX: 0000000000000246 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90009e066e0 R08: dffffc0000000000 R09: fffffbfff1f992b1
R10: fffffbfff1f992b1 R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff920013c0cb4
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:267
 rcu_read_lock include/linux/rcupdate.h:656 [inline]
 ext4_get_group_info+0xea/0x340 fs/ext4/ext4.h:3231
 ext4_mb_prefetch+0x123/0x5d0 fs/ext4/mballoc.c:2212
 ext4_mb_regular_allocator+0x8a5/0x28f0 fs/ext4/mballoc.c:2379
 ext4_mb_new_blocks+0xc6e/0x24f0 fs/ext4/mballoc.c:4982
 ext4_ext_map_blocks+0x2be3/0x7210 fs/ext4/extents.c:4238
 ext4_map_blocks+0xab3/0x1cb0 fs/ext4/inode.c:638
 ext4_getblk+0x187/0x6c0 fs/ext4/inode.c:848
 ext4_bread+0x2a/0x1c0 fs/ext4/inode.c:900
 ext4_append+0x1a4/0x360 fs/ext4/namei.c:67
 ext4_init_new_dir+0x337/0xa10 fs/ext4/namei.c:2768
 ext4_mkdir+0x4b8/0xc00 fs/ext4/namei.c:2814
 vfs_mkdir+0x45b/0x640 fs/namei.c:3819
 ovl_do_mkdir fs/overlayfs/overlayfs.h:161 [inline]
 ovl_mkdir_real+0x53/0x1a0 fs/overlayfs/dir.c:146
 ovl_create_real+0x280/0x490 fs/overlayfs/dir.c:193
 ovl_workdir_create+0x425/0x600 fs/overlayfs/super.c:788
 ovl_make_workdir+0xed/0x1140 fs/overlayfs/super.c:1355
 ovl_get_workdir fs/overlayfs/super.c:1492 [inline]
 ovl_fill_super+0x39ee/0x5370 fs/overlayfs/super.c:2035
 mount_nodev+0x52/0xe0 fs/super.c:1413
 legacy_get_tree+0xea/0x180 fs/fs_context.c:592
 vfs_get_tree+0x86/0x270 fs/super.c:1497
 do_new_mount fs/namespace.c:2903 [inline]
 path_mount+0x196f/0x2be0 fs/namespace.c:3233
 do_mount fs/namespace.c:3246 [inline]
 __do_sys_mount fs/namespace.c:3454 [inline]
 __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3431
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665f9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f68f2b87188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9
RDX: 00000000200000c0 RSI: 0000000020000000 RDI: 000000000040000a
RBP: 00000000004bfbb9 R08: 0000000020000100 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffe19002dff R14: 00007f68f2b87300 R15: 0000000000022000

Allocated by task 17768:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:427 [inline]
 ____kasan_kmalloc+0xc2/0xf0 mm/kasan/common.c:506
 kasan_kmalloc include/linux/kasan.h:233 [inline]
 __kmalloc+0xb4/0x380 mm/slub.c:4055
 kmalloc include/linux/slab.h:559 [inline]
 kzalloc include/linux/slab.h:684 [inline]
 fib6_info_alloc+0x2c/0xd0 net/ipv6/ip6_fib.c:154
 ip6_route_info_create+0x55d/0x1a10 net/ipv6/route.c:3638
 ip6_route_add+0x22/0x120 net/ipv6/route.c:3728
 inet6_rtm_newroute+0x2cd/0x2260 net/ipv6/route.c:5352
 rtnetlink_rcv_msg+0xb34/0xe70 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x5a2/0x900 net/socket.c:2350
 ___sys_sendmsg net/socket.c:2404 [inline]
 __sys_sendmsg+0x319/0x400 net/socket.c:2433
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Last potentially related work creation:
 kasan_save_stack+0x27/0x50 mm/kasan/common.c:38
 kasan_record_aux_stack+0xee/0x120 mm/kasan/generic.c:345
 __call_rcu kernel/rcu/tree.c:3039 [inline]
 call_rcu+0x1b1/0xa30 kernel/rcu/tree.c:3114
 fib6_info_release include/net/ip6_fib.h:337 [inline]
 ip6_route_info_create+0x10c4/0x1a10 net/ipv6/route.c:3718
 ip6_route_add+0x22/0x120 net/ipv6/route.c:3728
 inet6_rtm_newroute+0x2cd/0x2260 net/ipv6/route.c:5352
 rtnetlink_rcv_msg+0xb34/0xe70 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x5a2/0x900 net/socket.c:2350
 ___sys_sendmsg net/socket.c:2404 [inline]
 __sys_sendmsg+0x319/0x400 net/socket.c:2433
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Second to last potentially related work creation:
 kasan_save_stack+0x27/0x50 mm/kasan/common.c:38
 kasan_record_aux_stack+0xee/0x120 mm/kasan/generic.c:345
 insert_work+0x54/0x400 kernel/workqueue.c:1331
 __queue_work+0x981/0xcc0 kernel/workqueue.c:1497
 queue_work_on+0x111/0x200 kernel/workqueue.c:1524
 queue_work include/linux/workqueue.h:507 [inline]
 call_usermodehelper_exec+0x283/0x470 kernel/umh.c:433
 kobject_uevent_env+0x1349/0x1730 lib/kobject_uevent.c:617
 kvm_uevent_notify_change+0x309/0x3b0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4809
 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:877 [inline]
 kvm_put_kvm+0x9c/0xd10 arch/x86/kvm/../../../virt/kvm/kvm_main.c:920
 kvm_vcpu_release+0x53/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3120
 __fput+0x352/0x7b0 fs/file_table.c:280
 task_work_run+0x146/0x1c0 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x10b/0x1e0 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x26/0x70 kernel/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff8880145c7800
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 56 bytes to the right of
 192-byte region [ffff8880145c7800, ffff8880145c78c0)
The buggy address belongs to the page:
page:ffffea00005171c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x145c7
flags: 0xfff00000000200(slab)
raw: 00fff00000000200 ffffea00006474c0 0000000200000002 ffff888010c41a00
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880145c7780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8880145c7800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880145c7880: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
                                                                ^
 ffff8880145c7900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880145c7980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

In the ip6_route_info_create function, in the case that the nh pointer
is not NULL, the fib6_nh in fib6_info has not been allocated.
Therefore, when trying to free fib6_info in this error case using
fib6_info_release, the function will call fib6_info_destroy_rcu,
which it will access fib6_nh_release(f6i->fib6_nh);
However, f6i->fib6_nh doesn't have any refcount yet given the lack of allocation
causing the reported memory issue above.
Therefore, releasing the empty pointer directly instead would be the solution.

Fixes: f88d8ea67fbdb ("ipv6: Plumb support for nexthop object in a fib6_info")
Fixes: 706ec91916462 ("ipv6: Fix nexthop refcnt leak when creating ipv6 route info")
Signed-off-by: Coco Li <lixiaoyan@google.com>
Cc: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-10 13:37:05 +02:00
Francesco Ruggeri
3bfb58517d ipv6: record frag_max_size in atomic fragments in input path
[ Upstream commit e29f011e8fc04b2cdc742a2b9bbfa1b62518381a ]

Commit dbd1759e6a9c ("ipv6: on reassembly, record frag_max_size")
filled the frag_max_size field in IP6CB in the input path.
The field should also be filled in case of atomic fragments.

Fixes: dbd1759e6a9c ('ipv6: on reassembly, record frag_max_size')
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-03 08:59:15 +02:00
Taehee Yoo
37d6977599 mld: fix panic in mld_newpack()
[ Upstream commit 020ef930b826d21c5446fdc9db80fd72a791bc21 ]

mld_newpack() doesn't allow to allocate high order page,
only order-0 allocation is allowed.
If headroom size is too large, a kernel panic could occur in skb_put().

Test commands:
    ip netns del A
    ip netns del B
    ip netns add A
    ip netns add B
    ip link add veth0 type veth peer name veth1
    ip link set veth0 netns A
    ip link set veth1 netns B

    ip netns exec A ip link set lo up
    ip netns exec A ip link set veth0 up
    ip netns exec A ip -6 a a 2001:db8:0::1/64 dev veth0
    ip netns exec B ip link set lo up
    ip netns exec B ip link set veth1 up
    ip netns exec B ip -6 a a 2001:db8:0::2/64 dev veth1
    for i in {1..99}
    do
        let A=$i-1
        ip netns exec A ip link add ip6gre$i type ip6gre \
	local 2001:db8:$A::1 remote 2001:db8:$A::2 encaplimit 100
        ip netns exec A ip -6 a a 2001:db8:$i::1/64 dev ip6gre$i
        ip netns exec A ip link set ip6gre$i up

        ip netns exec B ip link add ip6gre$i type ip6gre \
	local 2001:db8:$A::2 remote 2001:db8:$A::1 encaplimit 100
        ip netns exec B ip -6 a a 2001:db8:$i::2/64 dev ip6gre$i
        ip netns exec B ip link set ip6gre$i up
    done

Splat looks like:
kernel BUG at net/core/skbuff.c:110!
invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.12.0+ #891
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:skb_panic+0x15d/0x15f
Code: 92 fe 4c 8b 4c 24 10 53 8b 4d 70 45 89 e0 48 c7 c7 00 ae 79 83
41 57 41 56 41 55 48 8b 54 24 a6 26 f9 ff <0f> 0b 48 8b 6c 24 20 89
34 24 e8 4a 4e 92 fe 8b 34 24 48 c7 c1 20
RSP: 0018:ffff88810091f820 EFLAGS: 00010282
RAX: 0000000000000089 RBX: ffff8881086e9000 RCX: 0000000000000000
RDX: 0000000000000089 RSI: 0000000000000008 RDI: ffffed1020123efb
RBP: ffff888005f6eac0 R08: ffffed1022fc0031 R09: ffffed1022fc0031
R10: ffff888117e00187 R11: ffffed1022fc0030 R12: 0000000000000028
R13: ffff888008284eb0 R14: 0000000000000ed8 R15: 0000000000000ec0
FS:  0000000000000000(0000) GS:ffff888117c00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8b801c5640 CR3: 0000000033c2c006 CR4: 00000000003706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ? ip6_mc_hdr.isra.26.constprop.46+0x12a/0x600
 ? ip6_mc_hdr.isra.26.constprop.46+0x12a/0x600
 skb_put.cold.104+0x22/0x22
 ip6_mc_hdr.isra.26.constprop.46+0x12a/0x600
 ? rcu_read_lock_sched_held+0x91/0xc0
 mld_newpack+0x398/0x8f0
 ? ip6_mc_hdr.isra.26.constprop.46+0x600/0x600
 ? lock_contended+0xc40/0xc40
 add_grhead.isra.33+0x280/0x380
 add_grec+0x5ca/0xff0
 ? mld_sendpack+0xf40/0xf40
 ? lock_downgrade+0x690/0x690
 mld_send_initial_cr.part.34+0xb9/0x180
 ipv6_mc_dad_complete+0x15d/0x1b0
 addrconf_dad_completed+0x8d2/0xbb0
 ? lock_downgrade+0x690/0x690
 ? addrconf_rs_timer+0x660/0x660
 ? addrconf_dad_work+0x73c/0x10e0
 addrconf_dad_work+0x73c/0x10e0

Allowing high order page allocation could fix this problem.

Fixes: 72e09ad107e7 ("ipv6: avoid high order allocations")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-03 08:59:14 +02:00
Eric Dumazet
50e5c93ca6 ipv6: remove extra dev_hold() for fallback tunnels
commit 0d7a7b2014b1a499a0fe24c9f3063d7856b5aaaf upstream.

My previous commits added a dev_hold() in tunnels ndo_init(),
but forgot to remove it from special functions setting up fallback tunnels.

Fallback tunnels do call their respective ndo_init()

This leads to various reports like :

unregister_netdevice: waiting for ip6gre0 to become free. Usage count = 2

Fixes: 48bb5697269a ("ip6_tunnel: sit: proper dev_{hold|put} in ndo_[un]init methods")
Fixes: 6289a98f0817 ("sit: proper dev_{hold|put} in ndo_[un]init methods")
Fixes: 40cb881b5aaa ("ip6_vti: proper dev_{hold|put} in ndo_[un]init methods")
Fixes: 7f700334be9a ("ip6_gre: proper dev_{hold|put} in ndo_[un]init methods")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 11:38:30 +02:00