linux-stable.git/net/xfrm, branch linux-5.6.y

xfrm: fix a NULL-ptr deref in xfrm_local_error

2020-06-03T06:23:30+00:00

commit f6a23d85d078c2ffde79c66ca81d0a1dde451649 upstream.

This patch is to fix a crash:

  [ ] kasan: GPF could be caused by NULL-ptr deref or user memory access
  [ ] general protection fault: 0000 [#1] SMP KASAN PTI
  [ ] RIP: 0010:ipv6_local_error+0xac/0x7a0
  [ ] Call Trace:
  [ ]  xfrm6_local_error+0x1eb/0x300
  [ ]  xfrm_local_error+0x95/0x130
  [ ]  __xfrm6_output+0x65f/0xb50
  [ ]  xfrm6_output+0x106/0x46f
  [ ]  udp_tunnel6_xmit_skb+0x618/0xbf0 [ip6_udp_tunnel]
  [ ]  vxlan_xmit_one+0xbc6/0x2c60 [vxlan]
  [ ]  vxlan_xmit+0x6a0/0x4276 [vxlan]
  [ ]  dev_hard_start_xmit+0x165/0x820
  [ ]  __dev_queue_xmit+0x1ff0/0x2b90
  [ ]  ip_finish_output2+0xd3e/0x1480
  [ ]  ip_do_fragment+0x182d/0x2210
  [ ]  ip_output+0x1d0/0x510
  [ ]  ip_send_skb+0x37/0xa0
  [ ]  raw_sendmsg+0x1b4c/0x2b80
  [ ]  sock_sendmsg+0xc0/0x110

This occurred when sending a v4 skb over vxlan6 over ipsec, in which case
skb->protocol == htons(ETH_P_IPV6) while skb->sk->sk_family == AF_INET in
xfrm_local_error(). Then it will go to xfrm6_local_error() where it tries
to get ipv6 info from a ipv4 sk.

This issue was actually fixed by Commit 628e341f319f ("xfrm: make local
error reporting more robust"), but brought back by Commit 844d48746e4b
("xfrm: choose protocol family by skb protocol").

So to fix it, we should call xfrm6_local_error() only when skb->protocol
is htons(ETH_P_IPV6) and skb->sk->sk_family is AF_INET6.

Fixes: 844d48746e4b ("xfrm: choose protocol family by skb protocol")
Reported-by: Xiumei Mu 
Signed-off-by: Xin Long 
Signed-off-by: Steffen Klassert 
Signed-off-by: Greg Kroah-Hartman

xfrm: fix a warning in xfrm_policy_insert_list

2020-06-03T06:23:30+00:00

commit ed17b8d377eaf6b4a01d46942b4c647378a79bdd upstream.

This waring can be triggered simply by:

  # ip xfrm policy update src 192.168.1.1/24 dst 192.168.1.2/24 dir in \
    priority 1 mark 0 mask 0x10  #[1]
  # ip xfrm policy update src 192.168.1.1/24 dst 192.168.1.2/24 dir in \
    priority 2 mark 0 mask 0x1   #[2]
  # ip xfrm policy update src 192.168.1.1/24 dst 192.168.1.2/24 dir in \
    priority 2 mark 0 mask 0x10  #[3]

Then dmesg shows:

  [ ] WARNING: CPU: 1 PID: 7265 at net/xfrm/xfrm_policy.c:1548
  [ ] RIP: 0010:xfrm_policy_insert_list+0x2f2/0x1030
  [ ] Call Trace:
  [ ]  xfrm_policy_inexact_insert+0x85/0xe50
  [ ]  xfrm_policy_insert+0x4ba/0x680
  [ ]  xfrm_add_policy+0x246/0x4d0
  [ ]  xfrm_user_rcv_msg+0x331/0x5c0
  [ ]  netlink_rcv_skb+0x121/0x350
  [ ]  xfrm_netlink_rcv+0x66/0x80
  [ ]  netlink_unicast+0x439/0x630
  [ ]  netlink_sendmsg+0x714/0xbf0
  [ ]  sock_sendmsg+0xe2/0x110

The issue was introduced by Commit 7cb8a93968e3 ("xfrm: Allow inserting
policies with matching mark and different priorities"). After that, the
policies [1] and [2] would be able to be added with different priorities.

However, policy [3] will actually match both [1] and [2]. Policy [1]
was matched due to the 1st 'return true' in xfrm_policy_mark_match(),
and policy [2] was matched due to the 2nd 'return true' in there. It
caused WARN_ON() in xfrm_policy_insert_list().

This patch is to fix it by only (the same value and priority) as the
same policy in xfrm_policy_mark_match().

Thanks to Yuehaibing, we could make this fix better.

v1->v2:
  - check policy->mark.v == pol->mark.v only without mask.

Fixes: 7cb8a93968e3 ("xfrm: Allow inserting policies with matching mark and different priorities")
Reported-by: Xiumei Mu 
Signed-off-by: Xin Long 
Signed-off-by: Steffen Klassert 
Signed-off-by: Greg Kroah-Hartman

xfrm interface: fix oops when deleting a x-netns interface

2020-06-03T06:23:30+00:00

commit c95c5f58b35ef995f66cb55547eee6093ab5fcb8 upstream.

Here is the steps to reproduce the problem:
ip netns add foo
ip netns add bar
ip -n foo link add xfrmi0 type xfrm dev lo if_id 42
ip -n foo link set xfrmi0 netns bar
ip netns del foo
ip netns del bar

Which results to:
[  186.686395] general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bd3: 0000 [#1] SMP PTI
[  186.687665] CPU: 7 PID: 232 Comm: kworker/u16:2 Not tainted 5.6.0+ #1
[  186.688430] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
[  186.689420] Workqueue: netns cleanup_net
[  186.689903] RIP: 0010:xfrmi_dev_uninit+0x1b/0x4b [xfrm_interface]
[  186.690657] Code: 44 f6 ff ff 31 c0 5b 5d 41 5c 41 5d 41 5e c3 48 8d 8f c0 08 00 00 8b 05 ce 14 00 00 48 8b 97 d0 08 00 00 48 8b 92 c0 0e 00 00 <48> 8b 14 c2 48 8b 02 48 85 c0 74 19 48 39 c1 75 0c 48 8b 87 c0 08
[  186.692838] RSP: 0018:ffffc900003b7d68 EFLAGS: 00010286
[  186.693435] RAX: 000000000000000d RBX: ffff8881b0f31000 RCX: ffff8881b0f318c0
[  186.694334] RDX: 6b6b6b6b6b6b6b6b RSI: 0000000000000246 RDI: ffff8881b0f31000
[  186.695190] RBP: ffffc900003b7df0 R08: ffff888236c07740 R09: 0000000000000040
[  186.696024] R10: ffffffff81fce1b8 R11: 0000000000000002 R12: ffffc900003b7d80
[  186.696859] R13: ffff8881edcc6a40 R14: ffff8881a1b6e780 R15: ffffffff81ed47c8
[  186.697738] FS:  0000000000000000(0000) GS:ffff888237dc0000(0000) knlGS:0000000000000000
[  186.698705] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  186.699408] CR2: 00007f2129e93148 CR3: 0000000001e0a000 CR4: 00000000000006e0
[  186.700221] Call Trace:
[  186.700508]  rollback_registered_many+0x32b/0x3fd
[  186.701058]  ? __rtnl_unlock+0x20/0x3d
[  186.701494]  ? arch_local_irq_save+0x11/0x17
[  186.702012]  unregister_netdevice_many+0x12/0x55
[  186.702594]  default_device_exit_batch+0x12b/0x150
[  186.703160]  ? prepare_to_wait_exclusive+0x60/0x60
[  186.703719]  cleanup_net+0x17d/0x234
[  186.704138]  process_one_work+0x196/0x2e8
[  186.704652]  worker_thread+0x1a4/0x249
[  186.705087]  ? cancel_delayed_work+0x92/0x92
[  186.705620]  kthread+0x105/0x10f
[  186.706000]  ? __kthread_bind_mask+0x57/0x57
[  186.706501]  ret_from_fork+0x35/0x40
[  186.706978] Modules linked in: xfrm_interface nfsv3 nfs_acl auth_rpcgss nfsv4 nfs lockd grace fscache sunrpc button parport_pc parport serio_raw evdev pcspkr loop ext4 crc16 mbcache jbd2 crc32c_generic 8139too ide_cd_mod cdrom ide_gd_mod ata_generic ata_piix libata scsi_mod piix psmouse i2c_piix4 ide_core 8139cp i2c_core mii floppy
[  186.710423] ---[ end trace 463bba18105537e5 ]---

The problem is that x-netns xfrm interface are not removed when the link
netns is removed. This causes later this oops when thoses interfaces are
removed.

Let's add a handler to remove all interfaces related to a netns when this
netns is removed.

Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces")
Reported-by: Christophe Gouault 
Signed-off-by: Nicolas Dichtel 
Signed-off-by: Steffen Klassert 
Signed-off-by: Greg Kroah-Hartman

xfrm: call xfrm_output_gso when inner_protocol is set in xfrm_output

2020-06-03T06:23:29+00:00

commit a204aef9fd77dce1efd9066ca4e44eede99cd858 upstream.

An use-after-free crash can be triggered when sending big packets over
vxlan over esp with esp offload enabled:

  [] BUG: KASAN: use-after-free in ipv6_gso_pull_exthdrs.part.8+0x32c/0x4e0
  [] Call Trace:
  []  dump_stack+0x75/0xa0
  []  kasan_report+0x37/0x50
  []  ipv6_gso_pull_exthdrs.part.8+0x32c/0x4e0
  []  ipv6_gso_segment+0x2c8/0x13c0
  []  skb_mac_gso_segment+0x1cb/0x420
  []  skb_udp_tunnel_segment+0x6b5/0x1c90
  []  inet_gso_segment+0x440/0x1380
  []  skb_mac_gso_segment+0x1cb/0x420
  []  esp4_gso_segment+0xae8/0x1709 [esp4_offload]
  []  inet_gso_segment+0x440/0x1380
  []  skb_mac_gso_segment+0x1cb/0x420
  []  __skb_gso_segment+0x2d7/0x5f0
  []  validate_xmit_skb+0x527/0xb10
  []  __dev_queue_xmit+0x10f8/0x2320 <---
  []  ip_finish_output2+0xa2e/0x1b50
  []  ip_output+0x1a8/0x2f0
  []  xfrm_output_resume+0x110e/0x15f0
  []  __xfrm4_output+0xe1/0x1b0
  []  xfrm4_output+0xa0/0x200
  []  iptunnel_xmit+0x5a7/0x920
  []  vxlan_xmit_one+0x1658/0x37a0 [vxlan]
  []  vxlan_xmit+0x5e4/0x3ec8 [vxlan]
  []  dev_hard_start_xmit+0x125/0x540
  []  __dev_queue_xmit+0x17bd/0x2320  <---
  []  ip6_finish_output2+0xb20/0x1b80
  []  ip6_output+0x1b3/0x390
  []  ip6_xmit+0xb82/0x17e0
  []  inet6_csk_xmit+0x225/0x3d0
  []  __tcp_transmit_skb+0x1763/0x3520
  []  tcp_write_xmit+0xd64/0x5fe0
  []  __tcp_push_pending_frames+0x8c/0x320
  []  tcp_sendmsg_locked+0x2245/0x3500
  []  tcp_sendmsg+0x27/0x40

As on the tx path of vxlan over esp, skb->inner_network_header would be
set on vxlan_xmit() and xfrm4_tunnel_encap_add(), and the later one can
overwrite the former one. It causes skb_udp_tunnel_segment() to use a
wrong skb->inner_network_header, then the issue occurs.

This patch is to fix it by calling xfrm_output_gso() instead when the
inner_protocol is set, in which gso_segment of inner_protocol will be
done first.

While at it, also improve some code around.

Fixes: 7862b4058b9f ("esp: Add gso handlers for esp4 and esp6")
Reported-by: Xiumei Mu 
Signed-off-by: Xin Long 
Signed-off-by: Steffen Klassert 
Signed-off-by: Greg Kroah-Hartman

xfrm: espintcp: save and call old ->sk_destruct

2020-06-03T06:23:29+00:00

commit 9f0cadc32d738f0f0c8e30be83be7087c7b85ee5 upstream.

When ESP encapsulation is enabled on a TCP socket, I'm replacing the
existing ->sk_destruct callback with espintcp_destruct. We still need to
call the old callback to perform the other cleanups when the socket is
destroyed. Save the old callback, and call it from espintcp_destruct.

Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)")
Signed-off-by: Sabrina Dubroca 
Signed-off-by: Steffen Klassert 
Signed-off-by: Greg Kroah-Hartman

xfrm: do pskb_pull properly in __xfrm_transport_prep

2020-06-03T06:23:29+00:00

commit 06a0afcfe2f551ff755849ea2549b0d8409fd9a0 upstream.

For transport mode, when ipv6 nexthdr is set, the packet format might
be like:

    ----------------------------------------------------
    |        | dest |     |     |      |  ESP    | ESP |
    | IP6 hdr| opts.| ESP | TCP | Data | Trailer | ICV |
    ----------------------------------------------------

and in __xfrm_transport_prep():

  pskb_pull(skb, skb->mac_len + sizeof(ip6hdr) + x->props.header_len);

it will pull the data pointer to the wrong position, as it missed the
nexthdrs/dest opts.

This patch is to fix it by using:

  pskb_pull(skb, skb_transport_offset(skb) + x->props.header_len);

as we can be sure transport_header points to ESP header at that moment.

It also fixes a panic when packets with ipv6 nexthdr are sent over
esp6 transport mode:

  [  100.473845] kernel BUG at net/core/skbuff.c:4325!
  [  100.478517] RIP: 0010:__skb_to_sgvec+0x252/0x260
  [  100.494355] Call Trace:
  [  100.494829]  skb_to_sgvec+0x11/0x40
  [  100.495492]  esp6_output_tail+0x12e/0x550 [esp6]
  [  100.496358]  esp6_xmit+0x1d5/0x260 [esp6_offload]
  [  100.498029]  validate_xmit_xfrm+0x22f/0x2e0
  [  100.499604]  __dev_queue_xmit+0x589/0x910
  [  100.502928]  ip6_finish_output2+0x2a5/0x5a0
  [  100.503718]  ip6_output+0x6c/0x120
  [  100.505198]  xfrm_output_resume+0x4bf/0x530
  [  100.508683]  xfrm6_output+0x3a/0xc0
  [  100.513446]  inet6_csk_xmit+0xa1/0xf0
  [  100.517335]  tcp_sendmsg+0x27/0x40
  [  100.517977]  sock_sendmsg+0x3e/0x60
  [  100.518648]  __sys_sendto+0xee/0x160

Fixes: c35fe4106b92 ("xfrm: Add mode handlers for IPsec on layer 2")
Signed-off-by: Xin Long 
Signed-off-by: Steffen Klassert 
Signed-off-by: Greg Kroah-Hartman

xfrm: allow to accept packets with ipv6 NEXTHDR_HOP in xfrm_input

2020-06-03T06:23:28+00:00

commit afcaf61be9d1dbdee5ec186d1dcc67b6b692180f upstream.

For beet mode, when it's ipv6 inner address with nexthdrs set,
the packet format might be:

    ----------------------------------------------------
    | outer  |     | dest |     |      |  ESP    | ESP |
    | IP hdr | ESP | opts.| TCP | Data | Trailer | ICV |
    ----------------------------------------------------

The nexthdr from ESP could be NEXTHDR_HOP(0), so it should
continue processing the packet when nexthdr returns 0 in
xfrm_input(). Otherwise, when ipv6 nexthdr is set, the
packet will be dropped.

I don't see any error cases that nexthdr may return 0. So
fix it by removing the check for nexthdr == 0.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Xin Long 
Signed-off-by: Steffen Klassert 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2020-03-27T21:56:55+00:00

Steffen Klassert says:

====================
pull request (net): ipsec 2020-03-27

1) Handle NETDEV_UNREGISTER for xfrm device to handle asynchronous
   unregister events cleanly. From Raed Salem.

2) Fix vti6 tunnel inter address family TX through bpf_redirect().
   From Nicolas Dichtel.

3) Fix lenght check in verify_sec_ctx_len() to avoid a
   slab-out-of-bounds. From Xin Long.

4) Add a missing verify_sec_ctx_len check in xfrm_add_acquire
   to avoid a possible out-of-bounds to access. From Xin Long.

5) Use built-in RCU list checking of hlist_for_each_entry_rcu
   to silence false lockdep warning in __xfrm6_tunnel_spi_lookup
   when CONFIG_PROVE_RCU_LIST is enabled. From Madhuparna Bhowmik.

6) Fix a panic on esp offload when crypto is done asynchronously.
   From Xin Long.

7) Fix a skb memory leak in an error path of vti6_rcv.
   From Torsten Hilbrich.

8) Fix a race that can lead to a doulbe free in xfrm_policy_timer.
   From Xin Long.
====================

Signed-off-by: David S. Miller

xfrm: policy: Fix doulbe free in xfrm_policy_timer

2020-03-24T05:56:54+00:00

After xfrm_add_policy add a policy, its ref is 2, then

                             xfrm_policy_timer
                               read_lock
                               xp->walk.dead is 0
                               ....
                               mod_timer()
xfrm_policy_kill
  policy->walk.dead = 1
  ....
  del_timer(&policy->timer)
    xfrm_pol_put //ref is 1
  xfrm_pol_put  //ref is 0
    xfrm_policy_destroy
      call_rcu
                                 xfrm_pol_hold //ref is 1
                               read_unlock
                               xfrm_pol_put //ref is 0
                                 xfrm_policy_destroy
                                  call_rcu

xfrm_policy_destroy is called twice, which may leads to
double free.

Call Trace:
RIP: 0010:refcount_warn_saturate+0x161/0x210
...
 xfrm_policy_timer+0x522/0x600
 call_timer_fn+0x1b3/0x5e0
 ? __xfrm_decode_session+0x2990/0x2990
 ? msleep+0xb0/0xb0
 ? _raw_spin_unlock_irq+0x24/0x40
 ? __xfrm_decode_session+0x2990/0x2990
 ? __xfrm_decode_session+0x2990/0x2990
 run_timer_softirq+0x5c5/0x10e0

Fix this by use write_lock_bh in xfrm_policy_kill.

Fixes: ea2dea9dacc2 ("xfrm: remove policy lock when accessing policy->walk.dead")
Signed-off-by: YueHaibing 
Acked-by: Timo Teräs 
Acked-by: Herbert Xu 
Signed-off-by: Steffen Klassert

esp: remove the skb from the chain when it's enqueued in cryptd_wq

2020-03-04T11:41:29+00:00

Xiumei found a panic in esp offload:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
  RIP: 0010:esp_output_done+0x101/0x160 [esp4]
  Call Trace:
   ? esp_output+0x180/0x180 [esp4]
   cryptd_aead_crypt+0x4c/0x90
   cryptd_queue_worker+0x6e/0xa0
   process_one_work+0x1a7/0x3b0
   worker_thread+0x30/0x390
   ? create_worker+0x1a0/0x1a0
   kthread+0x112/0x130
   ? kthread_flush_work_fn+0x10/0x10
   ret_from_fork+0x35/0x40

It was caused by that skb secpath is used in esp_output_done() after it's
been released elsewhere.

The tx path for esp offload is:

  __dev_queue_xmit()->
    validate_xmit_skb_list()->
      validate_xmit_xfrm()->
        esp_xmit()->
          esp_output_tail()->
            aead_request_set_callback(esp_output_done) <--[1]
            crypto_aead_encrypt()  <--[2]

In [1], .callback is set, and in [2] it will trigger the worker schedule,
later on a kernel thread will call .callback(esp_output_done), as the call
trace shows.

But in validate_xmit_xfrm():

  skb_list_walk_safe(skb, skb2, nskb) {
    ...
    err = x->type_offload->xmit(x, skb2, esp_features);  [esp_xmit]
    ...
  }

When the err is -EINPROGRESS, which means this skb2 will be enqueued and
later gets encrypted and sent out by .callback later in a kernel thread,
skb2 should be removed fromt skb chain. Otherwise, it will get processed
again outside validate_xmit_xfrm(), which could release skb secpath, and
cause the panic above.

This patch is to remove the skb from the chain when it's enqueued in
cryptd_wq. While at it, remove the unnecessary 'if (!skb)' check.

Fixes: 3dca3f38cfb8 ("xfrm: Separate ESP handling from segmentation for GRO packets.")
Reported-by: Xiumei Mu 
Signed-off-by: Xin Long 
Signed-off-by: Steffen Klassert