linux-stable.git/net/ipv6, branch v6.4.6

ipv6/addrconf: fix a potential refcount underflow for idev

2023-07-23T11:53:43+00:00

[ Upstream commit 06a0716949c22e2aefb648526580671197151acc ]

Now in addrconf_mod_rs_timer(), reference idev depends on whether
rs_timer is not pending. Then modify rs_timer timeout.

There is a time gap in [1], during which if the pending rs_timer
becomes not pending. It will miss to hold idev, but the rs_timer
is activated. Thus rs_timer callback function addrconf_rs_timer()
will be executed and put idev later without holding idev. A refcount
underflow issue for idev can be caused by this.

	if (!timer_pending(&idev->rs_timer))
		in6_dev_hold(idev);
		  <--------------[1]
	mod_timer(&idev->rs_timer, jiffies + when);

To fix the issue, hold idev if mod_timer() return 0.

Fixes: b7b1bfce0bb6 ("ipv6: split duplicate address detection and router solicitation timer")
Suggested-by: Eric Dumazet 
Signed-off-by: Ziyang Xuan 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

udp6: fix udp6_ehashfn() typo

2023-07-23T11:53:42+00:00

[ Upstream commit 51d03e2f2203e76ed02d33fb5ffbb5fc85ffaf54 ]

Amit Klein reported that udp6_ehash_secret was initialized but never used.

Fixes: 1bbdceef1e53 ("inet: convert inet_ehash_secret and ipv6_hash_secret to net_get_random_once")
Reported-by: Amit Klein 
Signed-off-by: Eric Dumazet 
Cc: Willy Tarreau 
Cc: Willem de Bruijn 
Cc: David Ahern 
Cc: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

icmp6: Fix null-ptr-deref of ip6_null_entry->rt6i_idev in icmp6_dev().

2023-07-23T11:53:42+00:00

[ Upstream commit 2aaa8a15de73874847d62eb595c6683bface80fd ]

With some IPv6 Ext Hdr (RPL, SRv6, etc.), we can send a packet that
has the link-local address as src and dst IP and will be forwarded to
an external IP in the IPv6 Ext Hdr.

For example, the script below generates a packet whose src IP is the
link-local address and dst is updated to 11::.

  # for f in $(find /proc/sys/net/ -name *seg6_enabled*); do echo 1 > $f; done
  # python3
  >>> from socket import *
  >>> from scapy.all import *
  >>>
  >>> SRC_ADDR = DST_ADDR = "fe80::5054:ff:fe12:3456"
  >>>
  >>> pkt = IPv6(src=SRC_ADDR, dst=DST_ADDR)
  >>> pkt /= IPv6ExtHdrSegmentRouting(type=4, addresses=["11::", "22::"], segleft=1)
  >>>
  >>> sk = socket(AF_INET6, SOCK_RAW, IPPROTO_RAW)
  >>> sk.sendto(bytes(pkt), (DST_ADDR, 0))

For such a packet, we call ip6_route_input() to look up a route for the
next destination in these three functions depending on the header type.

  * ipv6_rthdr_rcv()
  * ipv6_rpl_srh_rcv()
  * ipv6_srh_rcv()

If no route is found, ip6_null_entry is set to skb, and the following
dst_input(skb) calls ip6_pkt_drop().

Finally, in icmp6_dev(), we dereference skb_rt6_info(skb)->rt6i_idev->dev
as the input device is the loopback interface.  Then, we have to check if
skb_rt6_info(skb)->rt6i_idev is NULL or not to avoid NULL pointer deref
for ip6_null_entry.

BUG: kernel NULL pointer dereference, address: 0000000000000000
 PF: supervisor read access in kernel mode
 PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 157 Comm: python3 Not tainted 6.4.0-11996-gb121d614371c #35
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:icmp6_send (net/ipv6/icmp.c:436 net/ipv6/icmp.c:503)
Code: fe ff ff 48 c7 40 30 c0 86 5d 83 e8 c6 44 1c 00 e9 c8 fc ff ff 49 8b 46 58 48 83 e0 fe 0f 84 4a fb ff ff 48 8b 80 d0 00 00 00 <48> 8b 00 44 8b 88 e0 00 00 00 e9 34 fb ff ff 4d 85 ed 0f 85 69 01
RSP: 0018:ffffc90000003c70 EFLAGS: 00000286
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 00000000000000e0
RDX: 0000000000000021 RSI: 0000000000000000 RDI: ffff888006d72a18
RBP: ffffc90000003d80 R08: 0000000000000000 R09: 0000000000000001
R10: ffffc90000003d98 R11: 0000000000000040 R12: ffff888006d72a10
R13: 0000000000000000 R14: ffff8880057fb800 R15: ffffffff835d86c0
FS:  00007f9dc72ee740(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000057b2000 CR4: 00000000007506f0
PKRU: 55555554
Call Trace:
 
 ip6_pkt_drop (net/ipv6/route.c:4513)
 ipv6_rthdr_rcv (net/ipv6/exthdrs.c:640 net/ipv6/exthdrs.c:686)
 ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:437 (discriminator 5))
 ip6_input_finish (./include/linux/rcupdate.h:781 net/ipv6/ip6_input.c:483)
 __netif_receive_skb_one_core (net/core/dev.c:5455)
 process_backlog (./include/linux/rcupdate.h:781 net/core/dev.c:5895)
 __napi_poll (net/core/dev.c:6460)
 net_rx_action (net/core/dev.c:6529 net/core/dev.c:6660)
 __do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:554)
 do_softirq (kernel/softirq.c:454 kernel/softirq.c:441)
 
 
 __local_bh_enable_ip (kernel/softirq.c:381)
 __dev_queue_xmit (net/core/dev.c:4231)
 ip6_finish_output2 (./include/net/neighbour.h:544 net/ipv6/ip6_output.c:135)
 rawv6_sendmsg (./include/net/dst.h:458 ./include/linux/netfilter.h:303 net/ipv6/raw.c:656 net/ipv6/raw.c:914)
 sock_sendmsg (net/socket.c:725 net/socket.c:748)
 __sys_sendto (net/socket.c:2134)
 __x64_sys_sendto (net/socket.c:2146 net/socket.c:2142 net/socket.c:2142)
 do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
RIP: 0033:0x7f9dc751baea
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 7e c3 0f 1f 44 00 00 41 54 48 83 ec 30 44 89
RSP: 002b:00007ffe98712c38 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007ffe98712cf8 RCX: 00007f9dc751baea
RDX: 0000000000000060 RSI: 00007f9dc6460b90 RDI: 0000000000000003
RBP: 00007f9dc56e8be0 R08: 00007ffe98712d70 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: ffffffffc4653600 R14: 0000000000000001 R15: 00007f9dc6af5d1b
 
Modules linked in:
CR2: 0000000000000000
 ---[ end trace 0000000000000000 ]---
RIP: 0010:icmp6_send (net/ipv6/icmp.c:436 net/ipv6/icmp.c:503)
Code: fe ff ff 48 c7 40 30 c0 86 5d 83 e8 c6 44 1c 00 e9 c8 fc ff ff 49 8b 46 58 48 83 e0 fe 0f 84 4a fb ff ff 48 8b 80 d0 00 00 00 <48> 8b 00 44 8b 88 e0 00 00 00 e9 34 fb ff ff 4d 85 ed 0f 85 69 01
RSP: 0018:ffffc90000003c70 EFLAGS: 00000286
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 00000000000000e0
RDX: 0000000000000021 RSI: 0000000000000000 RDI: ffff888006d72a18
RBP: ffffc90000003d80 R08: 0000000000000000 R09: 0000000000000001
R10: ffffc90000003d98 R11: 0000000000000040 R12: ffff888006d72a10
R13: 0000000000000000 R14: ffff8880057fb800 R15: ffffffff835d86c0
FS:  00007f9dc72ee740(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000057b2000 CR4: 00000000007506f0
PKRU: 55555554
Kernel panic - not syncing: Fatal exception in interrupt
Kernel Offset: disabled

Fixes: 4832c30d5458 ("net: ipv6: put host and anycast routes on device with address")
Reported-by: Wang Yufen 
Closes: https://lore.kernel.org/netdev/c41403a9-c2f6-3b7e-0c96-e1901e605cd0@huawei.com/
Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: David Ahern 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

udp6: add a missing call into udp_fail_queue_rcv_skb tracepoint

2023-07-23T11:53:41+00:00

[ Upstream commit 8139dccd464aaee4a2c351506ff883733c6ca5a3 ]

The tracepoint has existed for 12 years, but it only covered udp
over the legacy IPv4 protocol. Having it enabled for udp6 removes
the unnecessary difference in error visibility.

Signed-off-by: Ivan Babrou 
Fixes: 296f7ea75b45 ("udp: add tracepoints for queueing skb to rcvbuf")
Acked-by: Paolo Abeni 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

Merge tag 'ipsec-2023-06-20' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2023-06-20T12:33:50+00:00

ipsec-2023-06-20

xfrm: Linearize the skb after offloading if needed.

2023-06-16T08:29:50+00:00

With offloading enabled, esp_xmit() gets invoked very late, from within
validate_xmit_xfrm() which is after validate_xmit_skb() validates and
linearizes the skb if the underlying device does not support fragments.

esp_output_tail() may add a fragment to the skb while adding the auth
tag/ IV. Devices without the proper support will then send skb->data
points to with the correct length so the packet will have garbage at the
end. A pcap sniffer will claim that the proper data has been sent since
it parses the skb properly.

It is not affected with INET_ESP_OFFLOAD disabled.

Linearize the skb after offloading if the sending hardware requires it.
It was tested on v4, v6 has been adopted.

Fixes: 7785bba299a8d ("esp: Add a software GRO codepath")
Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Steffen Klassert

udplite: Print deprecation notice.

2023-06-15T22:08:58+00:00

Recently syzkaller reported a 7-year-old null-ptr-deref [0] that occurs
when a UDP-Lite socket tries to allocate a buffer under memory pressure.

Someone should have stumbled on the bug much earlier if UDP-Lite had been
used in a real app.  Also, we do not always need a large UDP-Lite workload
to hit the bug since UDP and UDP-Lite share the same memory accounting
limit.

Removing UDP-Lite would simplify UDP code removing a bunch of conditionals
in fast path.

Let's add a deprecation notice when UDP-Lite socket is created and schedule
its removal to 2025.

Link: https://lore.kernel.org/netdev/20230523163305.66466-1-kuniyu@amazon.com/ [0]
Signed-off-by: Kuniyuki Iwashima 
Signed-off-by: Jakub Kicinski

xfrm: fix inbound ipv4/udp/esp packets to UDPv6 dualstack sockets

2023-06-09T06:16:34+00:00

Before Linux v5.8 an AF_INET6 SOCK_DGRAM (udp/udplite) socket
with SOL_UDP, UDP_ENCAP, UDP_ENCAP_ESPINUDP{,_NON_IKE} enabled
would just unconditionally use xfrm4_udp_encap_rcv(), afterwards
such a socket would use the newly added xfrm6_udp_encap_rcv()
which only handles IPv6 packets.

Cc: Sabrina Dubroca 
Cc: Steffen Klassert 
Cc: Jakub Kicinski 
Cc: Benedict Wong 
Cc: Yan Yan 
Fixes: 0146dca70b87 ("xfrm: add support for UDPv6 encapsulation of ESP")
Signed-off-by: Maciej Żenczykowski 
Reviewed-by: Simon Horman 
Reviewed-by: Sabrina Dubroca 
Signed-off-by: Steffen Klassert

ping6: Fix send to link-local addresses with VRF.

2023-06-09T01:59:57+00:00

Ping sockets can't send packets when they're bound to a VRF master
device and the output interface is set to a slave device.

For example, when net.ipv4.ping_group_range is properly set, so that
ping6 can use ping sockets, the following kind of commands fails:
  $ ip vrf exec red ping6 fe80::854:e7ff:fe88:4bf1%eth1

What happens is that sk->sk_bound_dev_if is set to the VRF master
device, but 'oif' is set to the real output device. Since both are set
but different, ping_v6_sendmsg() sees their value as inconsistent and
fails.

Fix this by allowing 'oif' to be a slave device of ->sk_bound_dev_if.

This fixes the following kselftest failure:
  $ ./fcnal-test.sh -t ipv6_ping
  [...]
  TEST: ping out, vrf device+address bind - ns-B IPv6 LLA        [FAIL]

Reported-by: Mirsad Todorovac 
Closes: https://lore.kernel.org/netdev/b6191f90-ffca-dbca-7d06-88a9788def9c@alu.unizg.hr/
Tested-by: Mirsad Todorovac 
Fixes: 5e457896986e ("net: ipv6: Fix ping to link-local addresses.")
Signed-off-by: Guillaume Nault 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/6c8b53108816a8d0d5705ae37bdc5a8322b5e3d9.1686153846.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski

ipv6: rpl: Fix Route of Death.

2023-06-07T03:59:08+00:00

A remote DoS vulnerability of RPL Source Routing is assigned CVE-2023-2156.

The Source Routing Header (SRH) has the following format:

  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |  Next Header  |  Hdr Ext Len  | Routing Type  | Segments Left |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | CmprI | CmprE |  Pad  |               Reserved                |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                                                               |
  .                                                               .
  .                        Addresses[1..n]                        .
  .                                                               .
  |                                                               |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The originator of an SRH places the first hop's IPv6 address in the IPv6
header's IPv6 Destination Address and the second hop's IPv6 address as
the first address in Addresses[1..n].

The CmprI and CmprE fields indicate the number of prefix octets that are
shared with the IPv6 Destination Address.  When CmprI or CmprE is not 0,
Addresses[1..n] are compressed as follows:

  1..n-1 : (16 - CmprI) bytes
       n : (16 - CmprE) bytes

Segments Left indicates the number of route segments remaining.  When the
value is not zero, the SRH is forwarded to the next hop.  Its address
is extracted from Addresses[n - Segment Left + 1] and swapped with IPv6
Destination Address.

When Segment Left is greater than or equal to 2, the size of SRH is not
changed because Addresses[1..n-1] are decompressed and recompressed with
CmprI.

OTOH, when Segment Left changes from 1 to 0, the new SRH could have a
different size because Addresses[1..n-1] are decompressed with CmprI and
recompressed with CmprE.

Let's say CmprI is 15 and CmprE is 0.  When we receive SRH with Segment
Left >= 2, Addresses[1..n-1] have 1 byte for each, and Addresses[n] has
16 bytes.  When Segment Left is 1, Addresses[1..n-1] is decompressed to
16 bytes and not recompressed.  Finally, the new SRH will need more room
in the header, and the size is (16 - 1) * (n - 1) bytes.

Here the max value of n is 255 as Segment Left is u8, so in the worst case,
we have to allocate 3825 bytes in the skb headroom.  However, now we only
allocate a small fixed buffer that is IPV6_RPL_SRH_WORST_SWAP_SIZE (16 + 7
bytes).  If the decompressed size overflows the room, skb_push() hits BUG()
below [0].

Instead of allocating the fixed buffer for every packet, let's allocate
enough headroom only when we receive SRH with Segment Left 1.

[0]:
skbuff: skb_under_panic: text:ffffffff81c9f6e2 len:576 put:576 head:ffff8880070b5180 data:ffff8880070b4fb0 tail:0x70 end:0x140 dev:lo
kernel BUG at net/core/skbuff.c:200!
invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 154 Comm: python3 Not tainted 6.4.0-rc4-00190-gc308e9ec0047 #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:skb_panic (net/core/skbuff.c:200)
Code: 4f 70 50 8b 87 bc 00 00 00 50 8b 87 b8 00 00 00 50 ff b7 c8 00 00 00 4c 8b 8f c0 00 00 00 48 c7 c7 80 6e 77 82 e8 ad 8b 60 ff <0f> 0b 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000003da0 EFLAGS: 00000246
RAX: 0000000000000085 RBX: ffff8880058a6600 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88807dc1c540 RDI: ffff88807dc1c540
RBP: ffffc90000003e48 R08: ffffffff82b392c8 R09: 00000000ffffdfff
R10: ffffffff82a592e0 R11: ffffffff82b092e0 R12: ffff888005b1c800
R13: ffff8880070b51b8 R14: ffff888005b1ca18 R15: ffff8880070b5190
FS:  00007f4539f0b740(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055670baf3000 CR3: 0000000005b0e000 CR4: 00000000007506f0
PKRU: 55555554
Call Trace:
 
 skb_push (net/core/skbuff.c:210)
 ipv6_rthdr_rcv (./include/linux/skbuff.h:2880 net/ipv6/exthdrs.c:634 net/ipv6/exthdrs.c:718)
 ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:437 (discriminator 5))
 ip6_input_finish (./include/linux/rcupdate.h:805 net/ipv6/ip6_input.c:483)
 __netif_receive_skb_one_core (net/core/dev.c:5494)
 process_backlog (./include/linux/rcupdate.h:805 net/core/dev.c:5934)
 __napi_poll (net/core/dev.c:6496)
 net_rx_action (net/core/dev.c:6565 net/core/dev.c:6696)
 __do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:572)
 do_softirq (kernel/softirq.c:472 kernel/softirq.c:459)
 
 
 __local_bh_enable_ip (kernel/softirq.c:396)
 __dev_queue_xmit (net/core/dev.c:4272)
 ip6_finish_output2 (./include/net/neighbour.h:544 net/ipv6/ip6_output.c:134)
 rawv6_sendmsg (./include/net/dst.h:458 ./include/linux/netfilter.h:303 net/ipv6/raw.c:656 net/ipv6/raw.c:914)
 sock_sendmsg (net/socket.c:724 net/socket.c:747)
 __sys_sendto (net/socket.c:2144)
 __x64_sys_sendto (net/socket.c:2156 net/socket.c:2152 net/socket.c:2152)
 do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
RIP: 0033:0x7f453a138aea
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 7e c3 0f 1f 44 00 00 41 54 48 83 ec 30 44 89
RSP: 002b:00007ffcc212a1c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007ffcc212a288 RCX: 00007f453a138aea
RDX: 0000000000000060 RSI: 00007f4539084c20 RDI: 0000000000000003
RBP: 00007f4538308e80 R08: 00007ffcc212a300 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: ffffffffc4653600 R14: 0000000000000001 R15: 00007f4539712d1b
 
Modules linked in:

Fixes: 8610c7c6e3bd ("net: ipv6: add support for rpl sr exthdr")
Reported-by: Max VA
Closes: https://www.interruptlabs.co.uk/articles/linux-ipv6-route-of-death
Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20230605180617.67284-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski