linux-stable.git/net/xfrm, branch linux-4.4.y

xfrm: Fix error reporting in xfrm_state_construct.

2021-07-20T14:22:38+00:00

[ Upstream commit 6fd06963fa74197103cdbb4b494763127b3f2f34 ]

When memory allocation for XFRMA_ENCAP or XFRMA_COADDR fails,
the error will not be reported because the -ENOMEM assignment
to the err variable is overwritten before. Fix this by moving
these two in front of the function so that memory allocation
failures will be reported.

Reported-by: Tobias Brunner 
Signed-off-by: Steffen Klassert 
Signed-off-by: Sasha Levin

xfrm: Fix oops in xfrm_replay_advance_bmp

2021-02-03T22:16:17+00:00

[ Upstream commit 56ce7c25ae1525d83cf80a880cf506ead1914250 ]

When setting xfrm replay_window to values higher than 32, a rare
page-fault occurs in xfrm_replay_advance_bmp:

  BUG: unable to handle page fault for address: ffff8af350ad7920
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD ad001067 P4D ad001067 PUD 0
  Oops: 0002 [#1] SMP PTI
  CPU: 3 PID: 30 Comm: ksoftirqd/3 Kdump: loaded Not tainted 5.4.52-050452-generic #202007160732
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
  RIP: 0010:xfrm_replay_advance_bmp+0xbb/0x130
  RSP: 0018:ffffa1304013ba40 EFLAGS: 00010206
  RAX: 000000000000010d RBX: 0000000000000002 RCX: 00000000ffffff4b
  RDX: 0000000000000018 RSI: 00000000004c234c RDI: 00000000ffb3dbff
  RBP: ffffa1304013ba50 R08: ffff8af330ad7920 R09: 0000000007fffffa
  R10: 0000000000000800 R11: 0000000000000010 R12: ffff8af29d6258c0
  R13: ffff8af28b95c700 R14: 0000000000000000 R15: ffff8af29d6258fc
  FS:  0000000000000000(0000) GS:ffff8af339ac0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffff8af350ad7920 CR3: 0000000015ee4000 CR4: 00000000001406e0
  Call Trace:
   xfrm_input+0x4e5/0xa10
   xfrm4_rcv_encap+0xb5/0xe0
   xfrm4_udp_encap_rcv+0x140/0x1c0

Analysis revealed offending code is when accessing:

	replay_esn->bmp[nr] |= (1U << bitnr);

with 'nr' being 0x07fffffa.

This happened in an SMP system when reordering of packets was present;
A packet arrived with a "too old" sequence number (outside the window,
i.e 'diff > replay_window'), and therefore the following calculation:

			bitnr = replay_esn->replay_window - (diff - pos);

yields a negative result, but since bitnr is u32 we get a large unsigned
quantity (in crash dump above: 0xffffff4b seen in ecx).

This was supposed to be protected by xfrm_input()'s former call to:

		if (x->repl->check(x, skb, seq)) {

However, the state's spinlock x->lock is *released* after '->check()'
is performed, and gets re-acquired before '->advance()' - which gives a
chance for a different core to update the xfrm state, e.g. by advancing
'replay_esn->seq' when it encounters more packets - leading to a
'diff > replay_window' situation when original core continues to
xfrm_replay_advance_bmp().

An attempt to fix this issue was suggested in commit bcf66bf54aab
("xfrm: Perform a replay check after return from async codepaths"),
by calling 'x->repl->recheck()' after lock is re-acquired, but fix
applied only to asyncronous crypto algorithms.

Augment the fix, by *always* calling 'recheck()' - irrespective if we're
using async crypto.

Fixes: 0ebea8ef3559 ("[IPSEC]: Move state lock into x->type->input")
Signed-off-by: Shmulik Ladkani 
Signed-off-by: Steffen Klassert 
Signed-off-by: Sasha Levin

net: xfrm: fix a race condition during allocing spi

2020-11-18T17:24:57+00:00

[ Upstream commit a779d91314ca7208b7feb3ad817b62904397c56d ]

we found that the following race condition exists in
xfrm_alloc_userspi flow:

user thread                                    state_hash_work thread
----                                           ----
xfrm_alloc_userspi()
 __find_acq_core()
   /*alloc new xfrm_state:x*/
   xfrm_state_alloc()
   /*schedule state_hash_work thread*/
   xfrm_hash_grow_check()   	               xfrm_hash_resize()
 xfrm_alloc_spi                                  /*hold lock*/
      x->id.spi = htonl(spi)                     spin_lock_bh(&net->xfrm.xfrm_state_lock)
      /*waiting lock release*/                     xfrm_hash_transfer()
      spin_lock_bh(&net->xfrm.xfrm_state_lock)      /*add x into hlist:net->xfrm.state_byspi*/
	                                                hlist_add_head_rcu(&x->byspi)
                                                 spin_unlock_bh(&net->xfrm.xfrm_state_lock)

    /*add x into hlist:net->xfrm.state_byspi 2 times*/
    hlist_add_head_rcu(&x->byspi)

1. a new state x is alloced in xfrm_state_alloc() and added into the bydst hlist
in  __find_acq_core() on the LHS;
2. on the RHS, state_hash_work thread travels the old bydst and tranfers every xfrm_state
(include x) into the new bydst hlist and new byspi hlist;
3. user thread on the LHS gets the lock and adds x into the new byspi hlist again.

So the same xfrm_state (x) is added into the same list_hash
(net->xfrm.state_byspi) 2 times that makes the list_hash become
an inifite loop.

To fix the race, x->id.spi = htonl(spi) in the xfrm_alloc_spi() is moved
to the back of spin_lock_bh, sothat state_hash_work thread no longer add x
which id.spi is zero into the hash_list.

Fixes: f034b5d4efdf ("[XFRM]: Dynamic xfrm_state hash table sizing.")
Signed-off-by: zhuoliang zhang 
Acked-by: Herbert Xu 
Signed-off-by: Steffen Klassert 
Signed-off-by: Sasha Levin

xfrm: Use correct address family in xfrm_state_find

2020-10-14T07:46:23+00:00

[ Upstream commit e94ee171349db84c7cfdc5fefbebe414054d0924 ]

The struct flowi must never be interpreted by itself as its size
depends on the address family.  Therefore it must always be grouped
with its original family value.

In this particular instance, the original family value is lost in
the function xfrm_state_find.  Therefore we get a bogus read when
it's coupled with the wrong family which would occur with inter-
family xfrm states.

This patch fixes it by keeping the original family value.

Note that the same bug could potentially occur in LSM through
the xfrm_state_pol_flow_match hook.  I checked the current code
there and it seems to be safe for now as only secid is used which
is part of struct flowi_common.  But that API should be changed
so that so that we don't get new bugs in the future.  We could
do that by replacing fl with just secid or adding a family field.

Reported-by: syzbot+577fbac3145a6eb2e7a5@syzkaller.appspotmail.com
Fixes: 48b8d78315bf ("[XFRM]: State selection update to use inner...")
Signed-off-by: Herbert Xu 
Signed-off-by: Steffen Klassert 
Signed-off-by: Sasha Levin

xfrm: clone whole liftime_cur structure in xfrm_do_migrate

2020-10-14T07:46:23+00:00

[ Upstream commit 8366685b2883e523f91e9816d7be371eb1144749 ]

When we clone state only add_time was cloned. It missed values like
bytes, packets.  Now clone the all members of the structure.

v1->v3:
 - use memcpy to copy the entire structure

Fixes: 80c9abaabf42 ("[XFRM]: Extension for dynamic update of endpoint address(es)")
Signed-off-by: Antony Antony 
Signed-off-by: Steffen Klassert 
Signed-off-by: Sasha Levin

xfrm: fix a NULL-ptr deref in xfrm_local_error

2020-06-03T06:12:13+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

2020-06-03T06:12:12+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: allow to accept packets with ipv6 NEXTHDR_HOP in xfrm_input

2020-06-03T06:12:12+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

xfrm: Fix memory leak of aead algorithm name

2020-05-10T08:26:04+00:00

commit b588479358ce26f32138e0f0a7ab0678f8e3e601 upstream.

commit 1a6509d99122 ("[IPSEC]: Add support for combined mode algorithms")
introduced aead. The function attach_aead kmemdup()s the algorithm
name during xfrm_state_construct().
However this memory is never freed.
Implementation has since been slightly modified in
commit ee5c23176fcc ("xfrm: Clone states properly on migration")
without resolving this leak.
This patch adds a kfree() call for the aead algorithm name.

Fixes: 1a6509d99122 ("[IPSEC]: Add support for combined mode algorithms")
Signed-off-by: Ilan Tayari 
Acked-by: Rami Rosen 
Signed-off-by: Steffen Klassert 
Signed-off-by: Greg Kroah-Hartman

xfrm_user: propagate sec ctx allocation errors

2020-05-10T08:26:04+00:00

commit 2f30ea5090cbc57ea573cdc66421264b3de3fb0a upstream.

When we fail to attach the security context in xfrm_state_construct()
we'll return 0 as error value which, in turn, will wrongly claim success
to userland when, in fact, we won't be adding / updating the XFRM state.

This is a regression introduced by commit fd21150a0fe1 ("[XFRM] netlink:
Inline attach_encap_tmpl(), attach_sec_ctx(), and attach_one_addr()").

Fix it by propagating the error returned by security_xfrm_state_alloc()
in this case.

Fixes: fd21150a0fe1 ("[XFRM] netlink: Inline attach_encap_tmpl()...")
Signed-off-by: Mathias Krause 
Cc: Thomas Graf 
Signed-off-by: Steffen Klassert 
Signed-off-by: Greg Kroah-Hartman