Commit Graph

7194 Commits

Author SHA1 Message Date
AuxXxilium
5fa3ea047a init: add dsm gpl source
Signed-off-by: AuxXxilium <info@auxxxilium.tech>
2024-07-05 18:00:04 +02:00
Vasily Averin
984e93b8e2 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 08:16:13 +02:00
Vasily Averin
2323690eb0 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 08:16:12 +02:00
Paolo Abeni
ce8fafb680 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: f88d8ea67f ("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 14:35:40 +02:00
Nicolas Dichtel
79ec7b5b2f ipv6: fix 'disable_policy' for fwd packets
[ Upstream commit ccd27f05ae7b8ebc40af5b004e94517a919aa862 ]

The goal of commit df789fe752 ("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: df789fe752 ("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 14:35:33 +02:00
Eric Dumazet
6cd9bd2a2d 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: bec1f6f697 ("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 14:36:22 +02:00
Eric Dumazet
2fee3cf4c9 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: 1da177e4c3 ("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 14:36:21 +02:00
Eric Dumazet
d60f07bcb7 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: 563d34d057 ("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 14:36:21 +02:00
Alexander Ovechkin
b61d8814c4 net: send SYNACK packet with accepted fwmark
commit 43b90bfad34bcb81b8a5bc7dc650800f4be1787e upstream.

commit e05a90ec9e ("net: reflect mark on tcp syn ack packets")
fixed IPv4 only.

This part is for the IPv6 side.

Fixes: e05a90ec9e ("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 14:36:20 +02:00
Vadim Fedorenko
34365de508 net: ipv6: fix return value of ip6_skb_dst_mtu
commit 40fc3054b45820c28ea3c65e2c86d041dc244a8a upstream.

Commit 628a5c5618 ("[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: 628a5c5618 ("[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 14:36:18 +02:00
Jakub Kicinski
a8585fdf42 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 09:44:53 +02:00
Willy Tarreau
8f939b7957 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 09:44:44 +02:00
Eric Dumazet
cebff3d9f7 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: 1da177e4c3 ("Linux-2.6.12-rc2")
Fixes: c1412fce7e ("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 16:56:28 +02:00
Eric Dumazet
2d58a38275 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: 47d3d7ac65 ("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 16:56:27 +02:00
Jakub Kicinski
c3fcfc4e36 ip6_tunnel: fix GRE6 segmentation
[ Upstream commit a6e3f2985a80ef6a45a17d2d9d9151f17ea3ce07 ]

Commit 6c11fbf97e ("ip6_tunnel: add MPLS transmit support")
moved assiging inner_ipproto down from ipxip6_tnl_xmit() to
its callee ip6_tnl_xmit(). The latter is also used by GRE.

Since commit 3872035241 ("gre: Use inner_proto to obtain inner
header protocol") GRE had been depending on skb->inner_protocol
during segmentation. It sets it in gre_build_header() and reads
it in gre_gso_segment(). Changes to ip6_tnl_xmit() overwrite
the protocol, resulting in GSO skbs getting dropped.

Note that inner_protocol is a union with inner_ipproto,
GRE uses the former while the change switched it to the latter
(always setting it to just IPPROTO_GRE).

Restore the original location of skb_set_inner_ipproto(),
it is unclear why it was moved in the first place.

Fixes: 6c11fbf97e ("ip6_tunnel: add MPLS transmit support")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Tested-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:56:25 +02:00
Sabrina Dubroca
1de9425286 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: 91657eafb6 ("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 16:56:14 +02:00
Zheng Yongjun
fedc4d4f54 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 08:47:20 -04:00
Paolo Abeni
8729ec8a22 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: 5d77dca828 ("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 14:42:42 +02:00
Florian Westphal
27e3d7da65 netfilter: nft_fib_ipv6: skip ipv6 packets from any to link-local
[ Upstream commit 12f36e9bf678a81d030ca1b693dcda62b55af7c5 ]

The ip6tables rpfilter match has an extra check to skip packets with
"::" source address.

Extend this to ipv6 fib expression.  Else ipv6 duplicate address detection
packets will fail rpf route check -- lookup returns -ENETUNREACH.

While at it, extend the prerouting check to also cover the ingress hook.

Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1543
Fixes: f6d0cbcf09 ("netfilter: nf_tables: add fib expression")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-23 14:42:42 +02:00
Coco Li
0987023582 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: f88d8ea67f ("ipv6: Plumb support for nexthop object in a fib6_info")
Fixes: 706ec91916 ("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 13:39:20 +02:00
Francesco Ruggeri
5a2e1ce7ab ipv6: record frag_max_size in atomic fragments in input path
[ Upstream commit e29f011e8fc04b2cdc742a2b9bbfa1b62518381a ]

Commit dbd1759e6a ("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: dbd1759e6a ('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 09:00:50 +02:00
Taehee Yoo
beb39adb15 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: 72e09ad107 ("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 09:00:48 +02:00
Eric Dumazet
ccecbcc9c5 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 11:40:55 +02:00
Eric Dumazet
019c426b53 ip6_tunnel: sit: proper dev_{hold|put} in ndo_[un]init methods
commit 48bb5697269a7cbe5194dbb044dc38c517e34c58 upstream.

Same reasons than for the previous commits :
6289a98f0817 ("sit: proper dev_{hold|put} in ndo_[un]init methods")
40cb881b5aaa ("ip6_vti: proper dev_{hold|put} in ndo_[un]init methods")
7f700334be9a ("ip6_gre: proper dev_{hold|put} in ndo_[un]init methods")

After adopting CONFIG_PCPU_DEV_REFCNT=n option, syzbot was able to trigger
a warning [1]

Issue here is that:

- all dev_put() should be paired with a corresponding prior dev_hold().

- A driver doing a dev_put() in its ndo_uninit() MUST also
  do a dev_hold() in its ndo_init(), only when ndo_init()
  is returning 0.

Otherwise, register_netdevice() would call ndo_uninit()
in its error path and release a refcount too soon.

[1]
WARNING: CPU: 1 PID: 21059 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Modules linked in:
CPU: 1 PID: 21059 Comm: syz-executor.4 Not tainted 5.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Code: 1d 6a 5a e8 09 31 ff 89 de e8 8d 1a ab fd 84 db 75 e0 e8 d4 13 ab fd 48 c7 c7 a0 e1 c1 89 c6 05 4a 5a e8 09 01 e8 2e 36 fb 04 <0f> 0b eb c4 e8 b8 13 ab fd 0f b6 1d 39 5a e8 09 31 ff 89 de e8 58
RSP: 0018:ffffc900025aefe8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff815c51f5 RDI: fffff520004b5def
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815bdf8e R11: 0000000000000000 R12: ffff888023488568
R13: ffff8880254e9000 R14: 00000000dfd82cfd R15: ffff88802ee2d7c0
FS:  00007f13bc590700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0943e74000 CR3: 0000000025273000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __refcount_dec include/linux/refcount.h:344 [inline]
 refcount_dec include/linux/refcount.h:359 [inline]
 dev_put include/linux/netdevice.h:4135 [inline]
 ip6_tnl_dev_uninit+0x370/0x3d0 net/ipv6/ip6_tunnel.c:387
 register_netdevice+0xadf/0x1500 net/core/dev.c:10308
 ip6_tnl_create2+0x1b5/0x400 net/ipv6/ip6_tunnel.c:263
 ip6_tnl_newlink+0x312/0x580 net/ipv6/ip6_tunnel.c:2052
 __rtnl_newlink+0x1062/0x1710 net/core/rtnetlink.c:3443
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3491
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Fixes: 919067cc845f ("net: add CONFIG_PCPU_DEV_REFCNT")
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 11:40:55 +02:00
Eric Dumazet
3c24dbd358 sit: proper dev_{hold|put} in ndo_[un]init methods
commit 6289a98f0817a4a457750d6345e754838eae9439 upstream.

After adopting CONFIG_PCPU_DEV_REFCNT=n option, syzbot was able to trigger
a warning [1]

Issue here is that:

- all dev_put() should be paired with a corresponding prior dev_hold().

- A driver doing a dev_put() in its ndo_uninit() MUST also
  do a dev_hold() in its ndo_init(), only when ndo_init()
  is returning 0.

Otherwise, register_netdevice() would call ndo_uninit()
in its error path and release a refcount too soon.

Fixes: 919067cc845f ("net: add CONFIG_PCPU_DEV_REFCNT")
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 11:40:55 +02:00
Eric Dumazet
b18b1548cb ip6_gre: proper dev_{hold|put} in ndo_[un]init methods
commit 7f700334be9aeb91d5d86ef9ad2d901b9b453e9b upstream.

After adopting CONFIG_PCPU_DEV_REFCNT=n option, syzbot was able to trigger
a warning [1]

Issue here is that:

- all dev_put() should be paired with a corresponding dev_hold(),
  and vice versa.

- A driver doing a dev_put() in its ndo_uninit() MUST also
  do a dev_hold() in its ndo_init(), only when ndo_init()
  is returning 0.

Otherwise, register_netdevice() would call ndo_uninit()
in its error path and release a refcount too soon.

ip6_gre for example (among others problematic drivers)
has to use dev_hold() in ip6gre_tunnel_init_common()
instead of from ip6gre_newlink_common(), covering
both ip6gre_tunnel_init() and ip6gre_tap_init()/

Note that ip6gre_tunnel_init_common() is not called from
ip6erspan_tap_init() thus we also need to add a dev_hold() there,
as ip6erspan_tunnel_uninit() does call dev_put()

[1]
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 0 PID: 8422 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Modules linked in:
CPU: 1 PID: 8422 Comm: syz-executor854 Not tainted 5.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Code: 1d 6a 5a e8 09 31 ff 89 de e8 8d 1a ab fd 84 db 75 e0 e8 d4 13 ab fd 48 c7 c7 a0 e1 c1 89 c6 05 4a 5a e8 09 01 e8 2e 36 fb 04 <0f> 0b eb c4 e8 b8 13 ab fd 0f b6 1d 39 5a e8 09 31 ff 89 de e8 58
RSP: 0018:ffffc900018befd0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88801ef19c40 RSI: ffffffff815c51f5 RDI: fffff52000317dec
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815bdf8e R11: 0000000000000000 R12: ffff888018cf4568
R13: ffff888018cf4c00 R14: ffff8880228f2000 R15: ffffffff8d659b80
FS:  00000000014eb300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d7bf2b3138 CR3: 0000000014933000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __refcount_dec include/linux/refcount.h:344 [inline]
 refcount_dec include/linux/refcount.h:359 [inline]
 dev_put include/linux/netdevice.h:4135 [inline]
 ip6gre_tunnel_uninit+0x3d7/0x440 net/ipv6/ip6_gre.c:420
 register_netdevice+0xadf/0x1500 net/core/dev.c:10308
 ip6gre_newlink_common.constprop.0+0x158/0x410 net/ipv6/ip6_gre.c:1984
 ip6gre_newlink+0x275/0x7a0 net/ipv6/ip6_gre.c:2017
 __rtnl_newlink+0x1062/0x1710 net/core/rtnetlink.c:3443
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3491
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46

Fixes: 919067cc845f ("net: add CONFIG_PCPU_DEV_REFCNT")
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 11:40:55 +02:00
Eric Dumazet
7bd851a6d3 ip6_vti: proper dev_{hold|put} in ndo_[un]init methods
[ Upstream commit 40cb881b5aaa0b69a7d93dec8440d5c62dae299f ]

After adopting CONFIG_PCPU_DEV_REFCNT=n option, syzbot was able to trigger
a warning [1]

Issue here is that:

- all dev_put() should be paired with a corresponding prior dev_hold().

- A driver doing a dev_put() in its ndo_uninit() MUST also
  do a dev_hold() in its ndo_init(), only when ndo_init()
  is returning 0.

Otherwise, register_netdevice() would call ndo_uninit()
in its error path and release a refcount too soon.

Therefore, we need to move dev_hold() call from
vti6_tnl_create2() to vti6_dev_init_gen()

[1]
WARNING: CPU: 0 PID: 15951 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Modules linked in:
CPU: 0 PID: 15951 Comm: syz-executor.3 Not tainted 5.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Code: 1d 6a 5a e8 09 31 ff 89 de e8 8d 1a ab fd 84 db 75 e0 e8 d4 13 ab fd 48 c7 c7 a0 e1 c1 89 c6 05 4a 5a e8 09 01 e8 2e 36 fb 04 <0f> 0b eb c4 e8 b8 13 ab fd 0f b6 1d 39 5a e8 09 31 ff 89 de e8 58
RSP: 0018:ffffc90001eaef28 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff815c51f5 RDI: fffff520003d5dd7
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815bdf8e R11: 0000000000000000 R12: ffff88801bb1c568
R13: ffff88801f69e800 R14: 00000000ffffffff R15: ffff888050889d40
FS:  00007fc79314e700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1c1ff47108 CR3: 0000000020fd5000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __refcount_dec include/linux/refcount.h:344 [inline]
 refcount_dec include/linux/refcount.h:359 [inline]
 dev_put include/linux/netdevice.h:4135 [inline]
 vti6_dev_uninit+0x31a/0x360 net/ipv6/ip6_vti.c:297
 register_netdevice+0xadf/0x1500 net/core/dev.c:10308
 vti6_tnl_create2+0x1b5/0x400 net/ipv6/ip6_vti.c:190
 vti6_newlink+0x9d/0xd0 net/ipv6/ip6_vti.c:1020
 __rtnl_newlink+0x1062/0x1710 net/core/rtnetlink.c:3443
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3491
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x331/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmmsg+0x195/0x470 net/socket.c:2490
 __do_sys_sendmmsg net/socket.c:2519 [inline]
 __se_sys_sendmmsg net/socket.c:2516 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2516

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-19 10:12:54 +02:00
Linus Lüssing
e2c34cacff net: bridge: mcast: fix broken length + header check for MRDv6 Adv.
[ Upstream commit 99014088156cd78867d19514a0bc771c4b86b93b ]

The IPv6 Multicast Router Advertisements parsing has the following two
issues:

For one thing, ICMPv6 MRD Advertisements are smaller than ICMPv6 MLD
messages (ICMPv6 MRD Adv.: 8 bytes vs. ICMPv6 MLDv1/2: >= 24 bytes,
assuming MLDv2 Reports with at least one multicast address entry).
When ipv6_mc_check_mld_msg() tries to parse an Multicast Router
Advertisement its MLD length check will fail - and it will wrongly
return -EINVAL, even if we have a valid MRD Advertisement. With the
returned -EINVAL the bridge code will assume a broken packet and will
wrongly discard it, potentially leading to multicast packet loss towards
multicast routers.

The second issue is the MRD header parsing in
br_ip6_multicast_mrd_rcv(): It wrongly checks for an ICMPv6 header
immediately after the IPv6 header (IPv6 next header type). However
according to RFC4286, section 2 all MRD messages contain a Router Alert
option (just like MLD). So instead there is an IPv6 Hop-by-Hop option
for the Router Alert between the IPv6 and ICMPv6 header, again leading
to the bridge wrongly discarding Multicast Router Advertisements.

To fix these two issues, introduce a new return value -ENODATA to
ipv6_mc_check_mld() to indicate a valid ICMPv6 packet with a hop-by-hop
option which is not an MLD but potentially an MRD packet. This also
simplifies further parsing in the bridge code, as ipv6_mc_check_mld()
already fully checks the ICMPv6 header and hop-by-hop option.

These issues were found and fixed with the help of the mrdisc tool
(https://github.com/troglobit/mrdisc).

Fixes: 4b3087c7e3 ("bridge: Snoop Multicast Router Advertisements")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-14 09:50:44 +02:00
Hristo Venev
33f3dab42a net: ip6_tunnel: Unregister catch-all devices
commit 941ea91e87a6e879ed82dad4949f6234f2702bec upstream.

Similarly to the sit case, we need to remove the tunnels with no
addresses that have been moved to another network namespace.

Fixes: 0bd8762824 ("ip6tnl: add x-netns support")
Signed-off-by: Hristo Venev <hristo@venev.name>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-21 13:00:57 +02:00
Hristo Venev
ea0340e632 net: sit: Unregister catch-all devices
commit 610f8c0fc8d46e0933955ce13af3d64484a4630a upstream.

A sit interface created without a local or a remote address is linked
into the `sit_net::tunnels_wc` list of its original namespace. When
deleting a network namespace, delete the devices that have been moved.

The following script triggers a null pointer dereference if devices
linked in a deleted `sit_net` remain:

    for i in `seq 1 30`; do
        ip netns add ns-test
        ip netns exec ns-test ip link add dev veth0 type veth peer veth1
        ip netns exec ns-test ip link add dev sit$i type sit dev veth0
        ip netns exec ns-test ip link set dev sit$i netns $$
        ip netns del ns-test
    done
    for i in `seq 1 30`; do
        ip link del dev sit$i
    done

Fixes: 5e6700b3bf ("sit: add support of x-netns")
Signed-off-by: Hristo Venev <hristo@venev.name>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-21 13:00:57 +02:00
Florian Westphal
1f3b9000cb netfilter: x_tables: fix compat match/target pad out-of-bound write
commit b29c457a6511435960115c0f548c4360d5f4801d upstream.

xt_compat_match/target_from_user doesn't check that zeroing the area
to start of next rule won't write past end of allocated ruleset blob.

Remove this code and zero the entire blob beforehand.

Reported-by: syzbot+cfc0247ac173f597aaaa@syzkaller.appspotmail.com
Reported-by: Andy Nguyen <theflow@google.com>
Fixes: 9fa492cdc1 ("[NETFILTER]: x_tables: simplify compat API")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-16 11:43:21 +02:00
Steffen Klassert
58f8f10740 xfrm: Provide private skb extensions for segmented and hw offloaded ESP packets
[ Upstream commit c7dbf4c08868d9db89b8bfe8f8245ca61b01ed2f ]

Commit 94579ac3f6 ("xfrm: Fix double ESP trailer insertion in IPsec
crypto offload.") added a XFRM_XMIT flag to avoid duplicate ESP trailer
insertion on HW offload. This flag is set on the secpath that is shared
amongst segments. This lead to a situation where some segments are
not transformed correctly when segmentation happens at layer 3.

Fix this by using private skb extensions for segmented and hw offloaded
ESP packets.

Fixes: 94579ac3f6 ("xfrm: Fix double ESP trailer insertion in IPsec crypto offload.")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-14 08:42:07 +02:00
Xin Long
ef4ddd1d6d esp: delete NETIF_F_SCTP_CRC bit from features for esp offload
[ Upstream commit 154deab6a3ba47792936edf77f2f13a1cbc4351d ]

Now in esp4/6_gso_segment(), before calling inner proto .gso_segment,
NETIF_F_CSUM_MASK bits are deleted, as HW won't be able to do the
csum for inner proto due to the packet encrypted already.

So the UDP/TCP packet has to do the checksum on its own .gso_segment.
But SCTP is using CRC checksum, and for that NETIF_F_SCTP_CRC should
be deleted to make SCTP do the csum in own .gso_segment as well.

In Xiumei's testing with SCTP over IPsec/veth, the packets are kept
dropping due to the wrong CRC checksum.

Reported-by: Xiumei Mu <xmu@redhat.com>
Fixes: 7862b4058b ("esp: Add gso handlers for esp4 and esp6")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-14 08:42:06 +02:00
Evan Nimmo
c7a175a24b xfrm: Use actual socket sk instead of skb socket for xfrm_output_resume
[ Upstream commit 9ab1265d52314fce1b51e8665ea6dbc9ac1a027c ]

A situation can occur where the interface bound to the sk is different
to the interface bound to the sk attached to the skb. The interface
bound to the sk is the correct one however this information is lost inside
xfrm_output2 and instead the sk on the skb is used in xfrm_output_resume
instead. This assumes that the sk bound interface and the bound interface
attached to the sk within the skb are the same which can lead to lookup
failures inside ip_route_me_harder resulting in the packet being dropped.

We have an l2tp v3 tunnel with ipsec protection. The tunnel is in the
global VRF however we have an encapsulated dot1q tunnel interface that
is within a different VRF. We also have a mangle rule that marks the
packets causing them to be processed inside ip_route_me_harder.

Prior to commit 31c70d5956 ("l2tp: keep original skb ownership") this
worked fine as the sk attached to the skb was changed from the dot1q
encapsulated interface to the sk for the tunnel which meant the interface
bound to the sk and the interface bound to the skb were identical.
Commit 46d6c5ae95 ("netfilter: use actual socket sk rather than skb sk
when routing harder") fixed some of these issues however a similar
problem existed in the xfrm code.

Fixes: 31c70d5956 ("l2tp: keep original skb ownership")
Signed-off-by: Evan Nimmo <evan.nimmo@alliedtelesis.co.nz>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-14 08:42:05 +02:00
Maciej Żenczykowski
5d9216b851 net-ipv6: bugfix - raw & sctp - switch to ipv6_can_nonlocal_bind()
commit 630e4576f83accf90366686f39808d665d8dbecc upstream.

Found by virtue of ipv6 raw sockets not honouring the per-socket
IP{,V6}_FREEBIND setting.

Based on hits found via:
  git grep '[.]ip_nonlocal_bind'
We fix both raw ipv6 sockets to honour IP{,V6}_FREEBIND and IP{,V6}_TRANSPARENT,
and we fix sctp sockets to honour IP{,V6}_TRANSPARENT (they already honoured
FREEBIND), and not just the ipv6 'ip_nonlocal_bind' sysctl.

The helper is defined as:
  static inline bool ipv6_can_nonlocal_bind(struct net *net, struct inet_sock *inet) {
    return net->ipv6.sysctl.ip_nonlocal_bind || inet->freebind || inet->transparent;
  }
so this change only widens the accepted opt-outs and is thus a clean bugfix.

I'm not entirely sure what 'fixes' tag to add, since this is AFAICT an ancient bug,
but IMHO this should be applied to stable kernels as far back as possible.
As such I'm adding a 'fixes' tag with the commit that originally added the helper,
which happened in 4.19.  Backporting to older LTS kernels (at least 4.9 and 4.14)
would presumably require open-coding it or backporting the helper as well.

Other possibly relevant commits:
  v4.18-rc6-1502-g83ba4645152d net: add helpers checking if socket can be bound to nonlocal address
  v4.18-rc6-1431-gd0c1f01138c4 net/ipv6: allow any source address for sendmsg pktinfo with ip_nonlocal_bind
  v4.14-rc5-271-gb71d21c274ef sctp: full support for ipv6 ip_nonlocal_bind & IP_FREEBIND
  v4.7-rc7-1883-g9b9742022888 sctp: support ipv6 nonlocal bind
  v4.1-12247-g35a256fee52c ipv6: Nonlocal bind

Cc: Lorenzo Colitti <lorenzo@google.com>
Fixes: 83ba464515 ("net: add helpers checking if socket can be bound to nonlocal address")
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Reviewed-By: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14 08:42:02 +02:00
Muhammad Usama Anjum
40375bc3d0 net: ipv6: check for validity before dereferencing cfg->fc_nlinfo.nlh
commit 864db232dc7036aa2de19749c3d5be0143b24f8f upstream.

nlh is being checked for validtity two times when it is dereferenced in
this function. Check for validity again when updating the flags through
nlh pointer to make the dereferencing safe.

CC: <stable@vger.kernel.org>
Addresses-Coverity: ("NULL pointer dereference")
Signed-off-by: Muhammad Usama Anjum <musamaanjum@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14 08:41:57 +02:00
Mark Tomlinson
c33f918758 Revert "netfilter: x_tables: Update remaining dereference to RCU"
[ Upstream commit abe7034b9a8d57737e80cc16d60ed3666990bdbf ]

This reverts commit 443d6e86f821a165fae3fc3fc13086d27ac140b1.

This (and the following) patch basically re-implemented the RCU
mechanisms of patch 784544739a. That patch was replaced because of the
performance problems that it created when replacing tables. Now, we have
the same issue: the call to synchronize_rcu() makes replacing tables
slower by as much as an order of magnitude.

Revert these patches and fix the issue in a different way.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:32:06 +02:00
Mark Tomlinson
520be4d1af Revert "netfilter: x_tables: Switch synchronization to RCU"
[ Upstream commit d3d40f237480abf3268956daf18cdc56edd32834 ]

This reverts commit cc00bcaa58.

This (and the preceding) patch basically re-implemented the RCU
mechanisms of patch 784544739a. That patch was replaced because of the
performance problems that it created when replacing tables. Now, we have
the same issue: the call to synchronize_rcu() makes replacing tables
slower by as much as an order of magnitude.

Prior to using RCU a script calling "iptables" approx. 200 times was
taking 1.16s. With RCU this increased to 11.59s.

Revert these patches and fix the issue in a different way.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:32:05 +02:00
Daniel Borkmann
0a245acbce net: Consolidate common blackhole dst ops
[ Upstream commit c4c877b2732466b4c63217baad05c96f775912c7 ]

Move generic blackhole dst ops to the core and use them from both
ipv4_dst_blackhole_ops and ip6_dst_blackhole_ops where possible. No
functional change otherwise. We need these also in other locations
and having to define them over and over again is not great.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:32:05 +02:00
Jakub Kicinski
5f64c4c550 ipv6: weaken the v4mapped source check
[ Upstream commit dcc32f4f183ab8479041b23a1525d48233df1d43 ]

This reverts commit 6af1799aaf.

Commit 6af1799aaf ("ipv6: drop incoming packets having a v4mapped
source address") introduced an input check against v4mapped addresses.
Use of such addresses on the wire is indeed questionable and not
allowed on public Internet. As the commit pointed out

  https://tools.ietf.org/html/draft-itojun-v6ops-v4mapped-harmful-02

lists potential issues.

Unfortunately there are applications which use v4mapped addresses,
and breaking them is a clear regression. For example v4mapped
addresses (or any semi-valid addresses, really) may be used
for uni-direction event streams or packet export.

Since the issue which sparked the addition of the check was with
TCP and request_socks in particular push the check down to TCPv6
and DCCP. This restores the ability to receive UDPv6 packets with
v4mapped address as the source.

Keep using the IPSTATS_MIB_INHDRERRORS statistic to minimize the
user-visible changes.

Fixes: 6af1799aaf ("ipv6: drop incoming packets having a v4mapped source address")
Reported-by: Sunyi Shao <sunyishao@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:32:01 +02:00
Wei Wang
7f041ee8ef ipv6: fix suspecious RCU usage warning
[ Upstream commit 28259bac7f1dde06d8ba324e222bbec9d4e92f2b ]

Syzbot reported the suspecious RCU usage in nexthop_fib6_nh() when
called from ipv6_route_seq_show(). The reason is ipv6_route_seq_start()
calls rcu_read_lock_bh(), while nexthop_fib6_nh() calls
rcu_dereference_rtnl().
The fix proposed is to add a variant of nexthop_fib6_nh() to use
rcu_dereference_bh_rtnl() for ipv6_route_seq_show().

The reported trace is as follows:
./include/net/nexthop.h:416 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
2 locks held by syz-executor.0/17895:
     at: seq_read+0x71/0x12a0 fs/seq_file.c:169
     at: seq_file_net include/linux/seq_file_net.h:19 [inline]
     at: ipv6_route_seq_start+0xaf/0x300 net/ipv6/ip6_fib.c:2616

stack backtrace:
CPU: 1 PID: 17895 Comm: syz-executor.0 Not tainted 4.15.0-syzkaller #0
Call Trace:
 [<ffffffff849edf9e>] __dump_stack lib/dump_stack.c:17 [inline]
 [<ffffffff849edf9e>] dump_stack+0xd8/0x147 lib/dump_stack.c:53
 [<ffffffff8480b7fa>] lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5745
 [<ffffffff8459ada6>] nexthop_fib6_nh include/net/nexthop.h:416 [inline]
 [<ffffffff8459ada6>] ipv6_route_native_seq_show net/ipv6/ip6_fib.c:2488 [inline]
 [<ffffffff8459ada6>] ipv6_route_seq_show+0x436/0x7a0 net/ipv6/ip6_fib.c:2673
 [<ffffffff81c556df>] seq_read+0xccf/0x12a0 fs/seq_file.c:276
 [<ffffffff81dbc62c>] proc_reg_read+0x10c/0x1d0 fs/proc/inode.c:231
 [<ffffffff81bc28ae>] do_loop_readv_writev fs/read_write.c:714 [inline]
 [<ffffffff81bc28ae>] do_loop_readv_writev fs/read_write.c:701 [inline]
 [<ffffffff81bc28ae>] do_iter_read+0x49e/0x660 fs/read_write.c:935
 [<ffffffff81bc81ab>] vfs_readv+0xfb/0x170 fs/read_write.c:997
 [<ffffffff81c88847>] kernel_readv fs/splice.c:361 [inline]
 [<ffffffff81c88847>] default_file_splice_read+0x487/0x9c0 fs/splice.c:416
 [<ffffffff81c86189>] do_splice_to+0x129/0x190 fs/splice.c:879
 [<ffffffff81c86f66>] splice_direct_to_actor+0x256/0x890 fs/splice.c:951
 [<ffffffff81c8777d>] do_splice_direct+0x1dd/0x2b0 fs/splice.c:1060
 [<ffffffff81bc4747>] do_sendfile+0x597/0xce0 fs/read_write.c:1459
 [<ffffffff81bca205>] SYSC_sendfile64 fs/read_write.c:1520 [inline]
 [<ffffffff81bca205>] SyS_sendfile64+0x155/0x170 fs/read_write.c:1506
 [<ffffffff81015fcf>] do_syscall_64+0x1ff/0x310 arch/x86/entry/common.c:305
 [<ffffffff84a00076>] entry_SYSCALL_64_after_hwframe+0x42/0xb7

Fixes: f88d8ea67f ("ipv6: Plumb support for nexthop object in a fib6_info")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Cc: David Ahern <dsahern@kernel.org>
Cc: Ido Schimmel <idosch@idosch.org>
Cc: Petr Machata <petrm@nvidia.com>
Cc: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.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>
2021-03-30 14:31:57 +02:00
Paul Moore
85178d76fe cipso,calipso: resolve a number of problems with the DOI refcounts
commit ad5d07f4a9cd671233ae20983848874731102c08 upstream.

The current CIPSO and CALIPSO refcounting scheme for the DOI
definitions is a bit flawed in that we:

1. Don't correctly match gets/puts in netlbl_cipsov4_list().
2. Decrement the refcount on each attempt to remove the DOI from the
   DOI list, only removing it from the list once the refcount drops
   to zero.

This patch fixes these problems by adding the missing "puts" to
netlbl_cipsov4_list() and introduces a more conventional, i.e.
not-buggy, refcounting mechanism to the DOI definitions.  Upon the
addition of a DOI to the DOI list, it is initialized with a refcount
of one, removing a DOI from the list removes it from the list and
drops the refcount by one; "gets" and "puts" behave as expected with
respect to refcounts, increasing and decreasing the DOI's refcount by
one.

Fixes: b1edeb1023 ("netlabel: Replace protocol/NetLabel linking with refrerence counts")
Fixes: d7cce01504 ("netlabel: Add support for removing a CALIPSO DOI.")
Reported-by: syzbot+9ec037722d2603a9f52e@syzkaller.appspotmail.com
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:15 +01:00
Jason A. Donenfeld
91796b6556 net: always use icmp{,v6}_ndo_send from ndo_start_xmit
commit 4372339efc06bc2a796f4cc9d0a7a929dfda4967 upstream.

There were a few remaining tunnel drivers that didn't receive the prior
conversion to icmp{,v6}_ndo_send. Knowing now that this could lead to
memory corrution (see ee576c47db60 ("net: icmp: pass zeroed opts from
icmp{,v6}_ndo_send before sending") for details), there's even more
imperative to have these all converted. So this commit goes through the
remaining cases that I could find and does a boring translation to the
ndo variety.

The Fixes: line below is the merge that originally added icmp{,v6}_
ndo_send and converted the first batch of icmp{,v6}_send users. The
rationale then for the change applies equally to this patch. It's just
that these drivers were left out of the initial conversion because these
network devices are hiding in net/ rather than in drivers/net/.

Cc: Florian Westphal <fw@strlen.de>
Cc: Willem de Bruijn <willemb@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Fixes: 803381f9f1 ("Merge branch 'icmp-account-for-NAT-when-sending-icmps-from-ndo-layer'")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-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>
2021-03-17 17:06:12 +01:00
Jason A. Donenfeld
ce4feb0111 net: icmp: pass zeroed opts from icmp{,v6}_ndo_send before sending
commit ee576c47db60432c37e54b1e2b43a8ca6d3a8dca upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:46 +01:00
Dongseok Yi
3d6df63a5c udp: ipv4: manipulate network header of NATed UDP GRO fraglist
commit c3df39ac9b0e3747bf8233ea9ce4ed5ceb3199d3 upstream.

UDP/IP header of UDP GROed frag_skbs are not updated even after NAT
forwarding. Only the header of head_skb from ip_finish_output_gso ->
skb_gso_segment is updated but following frag_skbs are not updated.

A call path skb_mac_gso_segment -> inet_gso_segment ->
udp4_ufo_fragment -> __udp_gso_segment -> __udp_gso_segment_list
does not try to update UDP/IP header of the segment list but copy
only the MAC header.

Update port, addr and check of each skb of the segment list in
__udp_gso_segment_list. It covers both SNAT and DNAT.

Fixes: 9fd1ff5d2a (udp: Support UDP fraglist GRO/GSO.)
Signed-off-by: Dongseok Yi <dseok.yi@samsung.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Link: https://lore.kernel.org/r/1611962007-80092-1-git-send-email-dseok.yi@samsung.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10 09:29:23 +01:00
Matteo Croce
9898801780 ipv6: set multicast flag on the multicast route
commit ceed9038b2783d14e0422bdc6fd04f70580efb4c upstream.

The multicast route ff00::/8 is created with type RTN_UNICAST:

  $ ip -6 -d route
  unicast ::1 dev lo proto kernel scope global metric 256 pref medium
  unicast fe80::/64 dev eth0 proto kernel scope global metric 256 pref medium
  unicast ff00::/8 dev eth0 proto kernel scope global metric 256 pref medium

Set the type to RTN_MULTICAST which is more appropriate.

Fixes: e8478e80e5 ("net/ipv6: Save route type in rt6_info")
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27 11:55:24 +01:00
Matteo Croce
3cb2de5242 ipv6: create multicast route with RTPROT_KERNEL
commit a826b04303a40d52439aa141035fca5654ccaccd upstream.

The ff00::/8 multicast route is created without specifying the fc_protocol
field, so the default RTPROT_BOOT value is used:

  $ ip -6 -d route
  unicast ::1 dev lo proto kernel scope global metric 256 pref medium
  unicast fe80::/64 dev eth0 proto kernel scope global metric 256 pref medium
  unicast ff00::/8 dev eth0 proto boot scope global metric 256 pref medium

As the documentation says, this value identifies routes installed during
boot, but the route is created when interface is set up.
Change the value to RTPROT_KERNEL which is a better value.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27 11:55:24 +01:00
Jakub Kicinski
00442a9621 net: sit: unregister_netdevice on newlink's error path
[ Upstream commit 47e4bb147a96f1c9b4e7691e7e994e53838bfff8 ]

We need to unregister the netdevice if config failed.
.ndo_uninit takes care of most of the heavy lifting.

This was uncovered by recent commit c269a24ce057 ("net: make
free_netdev() more lenient with unregistering devices").
Previously the partially-initialized device would be left
in the system.

Reported-and-tested-by: syzbot+2393580080a2da190f04@syzkaller.appspotmail.com
Fixes: e2f1f072db ("sit: allow to configure 6rd tunnels via netlink")
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20210114012947.2515313-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-23 16:04:02 +01:00
Willem de Bruijn
26413630f4 esp: avoid unneeded kmap_atomic call
[ Upstream commit 9bd6b629c39e3fa9e14243a6d8820492be1a5b2e ]

esp(6)_output_head uses skb_page_frag_refill to allocate a buffer for
the esp trailer.

It accesses the page with kmap_atomic to handle highmem. But
skb_page_frag_refill can return compound pages, of which
kmap_atomic only maps the first underlying page.

skb_page_frag_refill does not return highmem, because flag
__GFP_HIGHMEM is not set. ESP uses it in the same manner as TCP.
That also does not call kmap_atomic, but directly uses page_address,
in skb_copy_to_page_nocache. Do the same for ESP.

This issue has become easier to trigger with recent kmap local
debugging feature CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP.

Fixes: cac2661c53 ("esp4: Avoid skb_cow_data whenever possible")
Fixes: 03e2a30f6a ("esp6: Avoid skb_cow_data whenever possible")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-23 16:04:01 +01:00
Aya Levin
bbcb4746a6 net: ipv6: Validate GSO SKB before finish IPv6 processing
[ Upstream commit b210de4f8c97d57de051e805686248ec4c6cfc52 ]

There are cases where GSO segment's length exceeds the egress MTU:
 - Forwarding of a TCP GRO skb, when DF flag is not set.
 - Forwarding of an skb that arrived on a virtualisation interface
   (virtio-net/vhost/tap) with TSO/GSO size set by other network
   stack.
 - Local GSO skb transmitted on an NETIF_F_TSO tunnel stacked over an
   interface with a smaller MTU.
 - Arriving GRO skb (or GSO skb in a virtualised environment) that is
   bridged to a NETIF_F_TSO tunnel stacked over an interface with an
   insufficient MTU.

If so:
 - Consume the SKB and its segments.
 - Issue an ICMP packet with 'Packet Too Big' message containing the
   MTU, allowing the source host to reduce its Path MTU appropriately.

Note: These cases are handled in the same manner in IPv4 output finish.
This patch aligns the behavior of IPv6 and the one of IPv4.

Fixes: 9e50849054 ("netfilter: ipv6: move POSTROUTING invocation before fragmentation")
Signed-off-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/1610027418-30438-1-git-send-email-ayal@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-23 16:04:00 +01:00