linux-stable.git/net/ipv6, branch v5.3.10

net: ensure correct skb->tstamp in various fragmenters

2019-11-10T10:34:52+00:00

[ Upstream commit 9669fffc1415bb0c30e5d2ec98a8e1c3a418cb9c ]

Thomas found that some forwarded packets would be stuck
in FQ packet scheduler because their skb->tstamp contained
timestamps far in the future.

We thought we addressed this point in commit 8203e2d844d3
("net: clear skb->tstamp in forwarding paths") but there
is still an issue when/if a packet needs to be fragmented.

In order to meet EDT requirements, we have to make sure all
fragments get the original skb->tstamp.

Note that this original skb->tstamp should be zero in
forwarding path, but might have a non zero value in
output path if user decided so.

Fixes: fb420d5d91c1 ("tcp/fq: move back to CLOCK_MONOTONIC")
Signed-off-by: Eric Dumazet 
Reported-by: Thomas Bartschies 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: annotate accesses to sk->sk_incoming_cpu

2019-11-10T10:34:33+00:00

[ Upstream commit 7170a977743b72cf3eb46ef6ef89885dc7ad3621 ]

This socket field can be read and written by concurrent cpus.

Use READ_ONCE() and WRITE_ONCE() annotations to document this,
and avoid some compiler 'optimizations'.

KCSAN reported :

BUG: KCSAN: data-race in tcp_v4_rcv / tcp_v4_rcv

write to 0xffff88812220763c of 4 bytes by interrupt on cpu 0:
 sk_incoming_cpu_update include/net/sock.h:953 [inline]
 tcp_v4_rcv+0x1b3c/0x1bb0 net/ipv4/tcp_ipv4.c:1934
 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
 process_backlog+0x1d3/0x420 net/core/dev.c:5955
 napi_poll net/core/dev.c:6392 [inline]
 net_rx_action+0x3ae/0xa90 net/core/dev.c:6460
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082
 do_softirq.part.0+0x6b/0x80 kernel/softirq.c:337
 do_softirq kernel/softirq.c:329 [inline]
 __local_bh_enable_ip+0x76/0x80 kernel/softirq.c:189

read to 0xffff88812220763c of 4 bytes by interrupt on cpu 1:
 sk_incoming_cpu_update include/net/sock.h:952 [inline]
 tcp_v4_rcv+0x181a/0x1bb0 net/ipv4/tcp_ipv4.c:1934
 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
 process_backlog+0x1d3/0x420 net/core/dev.c:5955
 napi_poll net/core/dev.c:6392 [inline]
 net_rx_action+0x3ae/0xa90 net/core/dev.c:6460
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 run_ksoftirqd+0x46/0x60 kernel/softirq.c:603
 smpboot_thread_fn+0x37d/0x4a0 kernel/smpboot.c:165

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

erspan: fix the tun_info options_len check for erspan

2019-11-10T10:34:32+00:00

[ Upstream commit 2eb8d6d2910cfe3dc67dc056f26f3dd9c63d47cd ]

The check for !md doens't really work for ip_tunnel_info_opts(info) which
only does info + 1. Also to avoid out-of-bounds access on info, it should
ensure options_len is not less than erspan_metadata in both erspan_xmit()
and ip6erspan_tunnel_xmit().

Fixes: 1a66a836da ("gre: add collect_md mode to ERSPAN tunnel")
Signed-off-by: Xin Long 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipv6: fix listify ip6_rcv_finish in case of forwarding

2019-10-29T08:21:53+00:00

[ Upstream commit c7a42eb49212f93a800560662d17d5293960d3c3 ]

We need a similar fix for ipv6 as Commit 0761680d5215 ("net: ipv4: fix
listify ip_rcv_finish in case of forwarding") does for ipv4.

This issue can be reprocuded by syzbot since Commit 323ebb61e32b ("net:
use listified RX for handling GRO_NORMAL skbs") on net-next. The call
trace was:

  kernel BUG at include/linux/skbuff.h:2225!
  RIP: 0010:__skb_pull include/linux/skbuff.h:2225 [inline]
  RIP: 0010:skb_pull+0xea/0x110 net/core/skbuff.c:1902
  Call Trace:
    sctp_inq_pop+0x2f1/0xd80 net/sctp/inqueue.c:202
    sctp_endpoint_bh_rcv+0x184/0x8d0 net/sctp/endpointola.c:385
    sctp_inq_push+0x1e4/0x280 net/sctp/inqueue.c:80
    sctp_rcv+0x2807/0x3590 net/sctp/input.c:256
    sctp6_rcv+0x17/0x30 net/sctp/ipv6.c:1049
    ip6_protocol_deliver_rcu+0x2fe/0x1660 net/ipv6/ip6_input.c:397
    ip6_input_finish+0x84/0x170 net/ipv6/ip6_input.c:438
    NF_HOOK include/linux/netfilter.h:305 [inline]
    NF_HOOK include/linux/netfilter.h:299 [inline]
    ip6_input+0xe4/0x3f0 net/ipv6/ip6_input.c:447
    dst_input include/net/dst.h:442 [inline]
    ip6_sublist_rcv_finish+0x98/0x1e0 net/ipv6/ip6_input.c:84
    ip6_list_rcv_finish net/ipv6/ip6_input.c:118 [inline]
    ip6_sublist_rcv+0x80c/0xcf0 net/ipv6/ip6_input.c:282
    ipv6_list_rcv+0x373/0x4b0 net/ipv6/ip6_input.c:316
    __netif_receive_skb_list_ptype net/core/dev.c:5049 [inline]
    __netif_receive_skb_list_core+0x5fc/0x9d0 net/core/dev.c:5097
    __netif_receive_skb_list net/core/dev.c:5149 [inline]
    netif_receive_skb_list_internal+0x7eb/0xe60 net/core/dev.c:5244
    gro_normal_list.part.0+0x1e/0xb0 net/core/dev.c:5757
    gro_normal_list net/core/dev.c:5755 [inline]
    gro_normal_one net/core/dev.c:5769 [inline]
    napi_frags_finish net/core/dev.c:5782 [inline]
    napi_gro_frags+0xa6a/0xea0 net/core/dev.c:5855
    tun_get_user+0x2e98/0x3fa0 drivers/net/tun.c:1974
    tun_chr_write_iter+0xbd/0x156 drivers/net/tun.c:2020

Fixes: d8269e2cbf90 ("net: ipv6: listify ipv6_rcv() and ip6_rcv_finish()")
Fixes: 323ebb61e32b ("net: use listified RX for handling GRO_NORMAL skbs")
Reported-by: syzbot+eb349eeee854e389c36d@syzkaller.appspotmail.com
Reported-by: syzbot+4a0643a653ac375612d1@syzkaller.appspotmail.com
Signed-off-by: Xin Long 
Acked-by: Edward Cree 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

udp: only do GSO if # of segs > 1

2019-10-07T17:01:51+00:00

[ Upstream commit 4094871db1d65810acab3d57f6089aa39ef7f648 ]

Prior to this change an application sending <= 1MSS worth of data and
enabling UDP GSO would fail if the system had SW GSO enabled, but the
same send would succeed if HW GSO offload is enabled. In addition to this
inconsistency the error in the SW GSO case does not get back to the
application if sending out of a real device so the user is unaware of this
failure.

With this change we only perform GSO if the # of segments is > 1 even
if the application has enabled segmentation. I've also updated the
relevant udpgso selftests.

Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT")
Signed-off-by: Josh Hunt 
Reviewed-by: Willem de Bruijn 
Reviewed-by: Alexander Duyck 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

udp: fix gso_segs calculations

2019-10-07T17:01:50+00:00

[ Upstream commit 44b321e5020d782ad6e8ae8183f09b163be6e6e2 ]

Commit dfec0ee22c0a ("udp: Record gso_segs when supporting UDP segmentation offload")
added gso_segs calculation, but incorrectly got sizeof() the pointer and
not the underlying data type. In addition let's fix the v6 case.

Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT")
Fixes: dfec0ee22c0a ("udp: Record gso_segs when supporting UDP segmentation offload")
Signed-off-by: Josh Hunt 
Reviewed-by: Alexander Duyck 
Acked-by: Willem de Bruijn 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: Handle missing host route in __ipv6_ifa_notify

2019-10-07T17:01:47+00:00

[ Upstream commit 2d819d250a1393a3e725715425ab70a0e0772a71 ]

Rajendra reported a kernel panic when a link was taken down:

    [ 6870.263084] BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8
    [ 6870.271856] IP: [] __ipv6_ifa_notify+0x154/0x290

    

    [ 6870.570501] Call Trace:
    [ 6870.573238] [] ? ipv6_ifa_notify+0x26/0x40
    [ 6870.579665] [] ? addrconf_dad_completed+0x4c/0x2c0
    [ 6870.586869] [] ? ipv6_dev_mc_inc+0x196/0x260
    [ 6870.593491] [] ? addrconf_dad_work+0x10a/0x430
    [ 6870.600305] [] ? __switch_to_asm+0x34/0x70
    [ 6870.606732] [] ? process_one_work+0x18a/0x430
    [ 6870.613449] [] ? worker_thread+0x4d/0x490
    [ 6870.619778] [] ? process_one_work+0x430/0x430
    [ 6870.626495] [] ? kthread+0xd9/0xf0
    [ 6870.632145] [] ? __switch_to_asm+0x34/0x70
    [ 6870.638573] [] ? kthread_park+0x60/0x60
    [ 6870.644707] [] ? ret_from_fork+0x57/0x70
    [ 6870.650936] Code: 31 c0 31 d2 41 b9 20 00 08 02 b9 09 00 00 0

addrconf_dad_work is kicked to be scheduled when a device is brought
up. There is a race between addrcond_dad_work getting scheduled and
taking the rtnl lock and a process taking the link down (under rtnl).
The latter removes the host route from the inet6_addr as part of
addrconf_ifdown which is run for NETDEV_DOWN. The former attempts
to use the host route in __ipv6_ifa_notify. If the down event removes
the host route due to the race to the rtnl, then the BUG listed above
occurs.

Since the DAD sequence can not be aborted, add a check for the missing
host route in __ipv6_ifa_notify. The only way this should happen is due
to the previously mentioned race. The host route is created when the
address is added to an interface; it is only removed on a down event
where the address is kept. Add a warning if the host route is missing
AND the device is up; this is a situation that should never happen.

Fixes: f1705ec197e7 ("net: ipv6: Make address flushing on ifdown optional")
Reported-by: Rajendra Dendukuri 
Signed-off-by: David Ahern 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: drop incoming packets having a v4mapped source address

2019-10-07T17:01:46+00:00

[ Upstream commit 6af1799aaf3f1bc8defedddfa00df3192445bbf3 ]

This began with a syzbot report. syzkaller was injecting
IPv6 TCP SYN packets having a v4mapped source address.

After an unsuccessful 4-tuple lookup, TCP creates a request
socket (SYN_RECV) and calls reqsk_queue_hash_req()

reqsk_queue_hash_req() calls sk_ehashfn(sk)

At this point we have AF_INET6 sockets, and the heuristic
used by sk_ehashfn() to either hash the IPv4 or IPv6 addresses
is to use ipv6_addr_v4mapped(&sk->sk_v6_daddr)

For the particular spoofed packet, we end up hashing V4 addresses
which were not initialized by the TCP IPv6 stack, so KMSAN fired
a warning.

I first fixed sk_ehashfn() to test both source and destination addresses,
but then faced various problems, including user-space programs
like packetdrill that had similar assumptions.

Instead of trying to fix the whole ecosystem, it is better
to admit that we have a dual stack behavior, and that we
can not build linux kernels without V4 stack anyway.

The dual stack API automatically forces the traffic to be IPv4
if v4mapped addresses are used at bind() or connect(), so it makes
no sense to allow IPv6 traffic to use the same v4mapped class.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet 
Cc: Florian Westphal 
Cc: Hannes Frederic Sowa 
Reported-by: syzbot 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: fix a typo in fib6_rule_lookup()

2019-10-05T13:11:19+00:00

[ Upstream commit 7b09c2d052db4b4ad0b27b97918b46a7746966fa ]

Yi Ren reported an issue discovered by syzkaller, and bisected
to the cited commit.

Many thanks to Yi, this trivial patch does not reflect the patient
work that has been done.

Fixes: d64a1f574a29 ("ipv6: honor RT6_LOOKUP_F_DST_NOREF in rule lookup logic")
Signed-off-by: Eric Dumazet 
Acked-by: Wei Wang 
Bisected-and-reported-by: Yi Ren 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

ipv6: do not free rt if FIB_LOOKUP_NOREF is set on suppress rule

2019-10-05T13:11:13+00:00

[ Upstream commit ca7a03c4175366a92cee0ccc4fec0038c3266e26 ]

Commit 7d9e5f422150 removed references from certain dsts, but accounting
for this never translated down into the fib6 suppression code. This bug
was triggered by WireGuard users who use wg-quick(8), which uses the
"suppress-prefix" directive to ip-rule(8) for routing all of their
internet traffic without routing loops. The test case added here
causes the reference underflow by causing packets to evaluate a suppress
rule.

Fixes: 7d9e5f422150 ("ipv6: convert major tx path to use RT6_LOOKUP_F_DST_NOREF")
Signed-off-by: Jason A. Donenfeld 
Acked-by: Wei Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman