linux-stable.git/drivers/net/wireguard, branch v5.10

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-09-22T23:45:34+00:00

Two minor conflicts:

1) net/ipv4/route.c, adding a new local variable while
   moving another local variable and removing it's
   initial assignment.

2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
   One pretty prints the port mode differently, whilst another
   changes the driver to try and obtain the port mode from
   the port node rather than the switch node.

Signed-off-by: David S. Miller

wireguard: peerlookup: take lock before checking hash in replace operation

2020-09-09T18:31:38+00:00

Eric's suggested fix for the previous commit's mentioned race condition
was to simply take the table->lock in wg_index_hashtable_replace(). The
table->lock of the hash table is supposed to protect the bucket heads,
not the entires, but actually, since all the mutator functions are
already taking it, it makes sense to take it too for the test to
hlist_unhashed, as a defense in depth measure, so that it no longer
races with deletions, regardless of what other locks are protecting
individual entries. This is sensible from a performance perspective
because, as Eric pointed out, the case of being unhashed is already the
unlikely case, so this won't add common contention. And comparing
instructions, this basically doesn't make much of a difference other
than pushing and popping %r13, used by the new `bool ret`. More
generally, I like the idea of locking consistency across table mutator
functions, and this might let me rest slightly easier at night.

Suggested-by: Eric Dumazet 
Link: https://lore.kernel.org/wireguard/20200908145911.4090480-1-edumazet@google.com/
Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: David S. Miller

wireguard: noise: take lock when removing handshake entry from table

2020-09-09T18:31:37+00:00

Eric reported that syzkaller found a race of this variety:

CPU 1                                       CPU 2
-------------------------------------------|---------------------------------------
wg_index_hashtable_replace(old, ...)       |
  if (hlist_unhashed(&old->index_hash))    |
                                           | wg_index_hashtable_remove(old)
                                           |   hlist_del_init_rcu(&old->index_hash)
				           |     old->index_hash.pprev = NULL
  hlist_replace_rcu(&old->index_hash, ...) |
    *old->index_hash.pprev                 |

Syzbot wasn't actually able to reproduce this more than once or create a
reproducer, because the race window between checking "hlist_unhashed" and
calling "hlist_replace_rcu" is just so small. Adding an mdelay(5) or
similar there helps make this demonstrable using this simple script:

    #!/bin/bash
    set -ex
    trap 'kill $pid1; kill $pid2; ip link del wg0; ip link del wg1' EXIT
    ip link add wg0 type wireguard
    ip link add wg1 type wireguard
    wg set wg0 private-key <(wg genkey) listen-port 9999
    wg set wg1 private-key <(wg genkey) peer $(wg show wg0 public-key) endpoint 127.0.0.1:9999 persistent-keepalive 1
    wg set wg0 peer $(wg show wg1 public-key)
    ip link set wg0 up
    yes link set wg1 up | ip -force -batch - &
    pid1=$!
    yes link set wg1 down | ip -force -batch - &
    pid2=$!
    wait

The fundumental underlying problem is that we permit calls to wg_index_
hashtable_remove(handshake.entry) without requiring the caller to take
the handshake mutex that is intended to protect members of handshake
during mutations. This is consistently the case with calls to wg_index_
hashtable_insert(handshake.entry) and wg_index_hashtable_replace(
handshake.entry), but it's missing from a pertinent callsite of wg_
index_hashtable_remove(handshake.entry). So, this patch makes sure that
mutex is taken.

The original code was a little bit funky though, in the form of:

    remove(handshake.entry)
    lock(), memzero(handshake.some_members), unlock()
    remove(handshake.entry)

The original intention of that double removal pattern outside the lock
appears to be some attempt to prevent insertions that might happen while
locks are dropped during expensive crypto operations, but actually, all
callers of wg_index_hashtable_insert(handshake.entry) take the write
lock and then explicitly check handshake.state, as they should, which
the aforementioned memzero clears, which means an insertion should
already be impossible. And regardless, the original intention was
necessarily racy, since it wasn't guaranteed that something else would
run after the unlock() instead of after the remove(). So, from a
soundness perspective, it seems positive to remove what looks like a
hack at best.

The crash from both syzbot and from the script above is as follows:

  general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
  CPU: 0 PID: 7395 Comm: kworker/0:3 Not tainted 5.9.0-rc4-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  Workqueue: wg-kex-wg1 wg_packet_handshake_receive_worker
  RIP: 0010:hlist_replace_rcu include/linux/rculist.h:505 [inline]
  RIP: 0010:wg_index_hashtable_replace+0x176/0x330 drivers/net/wireguard/peerlookup.c:174
  Code: 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 01 00 0f 85 44 01 00 00 48 b9 00 00 00 00 00 fc ff df 48 8b 45 10 48 89 c6 48 c1 ee 03 <80> 3c 0e 00 0f 85 06 01 00 00 48 85 d2 4c 89 28 74 47 e8 a3 4f b5
  RSP: 0018:ffffc90006a97bf8 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff888050ffc4f8 RCX: dffffc0000000000
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88808e04e010
  RBP: ffff88808e04e000 R08: 0000000000000001 R09: ffff8880543d0000
  R10: ffffed100a87a000 R11: 000000000000016e R12: ffff8880543d0000
  R13: ffff88808e04e008 R14: ffff888050ffc508 R15: ffff888050ffc500
  FS:  0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000f5505db0 CR3: 0000000097cf7000 CR4: 00000000001526f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
  wg_noise_handshake_begin_session+0x752/0xc9a drivers/net/wireguard/noise.c:820
  wg_receive_handshake_packet drivers/net/wireguard/receive.c:183 [inline]
  wg_packet_handshake_receive_worker+0x33b/0x730 drivers/net/wireguard/receive.c:220
  process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
  worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
  kthread+0x3b5/0x4a0 kernel/kthread.c:292
  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Reported-by: syzbot 
Reported-by: Eric Dumazet 
Link: https://lore.kernel.org/wireguard/20200908145911.4090480-1-edumazet@google.com/
Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: David S. Miller

netlink: consistently use NLA_POLICY_MIN_LEN()

2020-08-18T19:28:45+00:00

Change places that open-code NLA_POLICY_MIN_LEN() to
use the macro instead, giving us flexibility in how we
handle the details of the macro.

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

netlink: consistently use NLA_POLICY_EXACT_LEN()

2020-08-18T19:28:45+00:00

Change places that open-code NLA_POLICY_EXACT_LEN() to
use the macro instead, giving us flexibility in how we
handle the details of the macro.

Signed-off-by: Johannes Berg 
Acked-by: Matthieu Baerts 
Signed-off-by: David S. Miller

mm, treewide: rename kzfree() to kfree_sensitive()

2020-08-07T18:33:22+00:00

As said by Linus:

  A symmetric naming is only helpful if it implies symmetries in use.
  Otherwise it's actively misleading.

  In "kzalloc()", the z is meaningful and an important part of what the
  caller wants.

  In "kzfree()", the z is actively detrimental, because maybe in the
  future we really _might_ want to use that "memfill(0xdeadbeef)" or
  something. The "zero" part of the interface isn't even _relevant_.

The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.

Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.

The renaming is done by using the command sequence:

  git grep -w --name-only kzfree |\
  xargs sed -i 's/kzfree/kfree_sensitive/'

followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.

[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]

Suggested-by: Joe Perches 
Signed-off-by: Waiman Long 
Signed-off-by: Andrew Morton 
Acked-by: David Howells 
Acked-by: Michal Hocko 
Acked-by: Johannes Weiner 
Cc: Jarkko Sakkinen 
Cc: James Morris 
Cc: "Serge E. Hallyn" 
Cc: Joe Perches 
Cc: Matthew Wilcox 
Cc: David Rientjes 
Cc: Dan Carpenter 
Cc: "Jason A . Donenfeld" 
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds

wireguard: queueing: make use of ip_tunnel_parse_protocol

2020-06-30T19:29:39+00:00

Now that wg_examine_packet_protocol has been added for general
consumption as ip_tunnel_parse_protocol, it's possible to remove
wg_examine_packet_protocol and simply use the new
ip_tunnel_parse_protocol function directly.

Signed-off-by: Jason A. Donenfeld 
Signed-off-by: David S. Miller

wireguard: implement header_ops->parse_protocol for AF_PACKET

2020-06-30T19:29:39+00:00

WireGuard uses skb->protocol to determine packet type, and bails out if
it's not set or set to something it's not expecting. For AF_PACKET
injection, we need to support its call chain of:

    packet_sendmsg -> packet_snd -> packet_parse_headers ->
      dev_parse_header_protocol -> parse_protocol

Without a valid parse_protocol, this returns zero, and wireguard then
rejects the skb. So, this wires up the ip_tunnel handler for layer 3
packets for that case.

Reported-by: Hans Wippel 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: David S. Miller

wireguard: receive: account for napi_gro_receive never returning GRO_DROP

2020-06-25T23:16:21+00:00

The napi_gro_receive function no longer returns GRO_DROP ever, making
handling GRO_DROP dead code. This commit removes that dead code.
Further, it's not even clear that device drivers have any business in
taking action after passing off received packets; that's arguably out of
their hands.

Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
Fixes: 6570bc79c0df ("net: core: use listified Rx for GRO_NORMAL in napi_gro_receive()")
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: David S. Miller

wireguard: device: avoid circular netns references

2020-06-23T21:50:34+00:00

Before, we took a reference to the creating netns if the new netns was
different. This caused issues with circular references, with two
wireguard interfaces swapping namespaces. The solution is to rather not
take any extra references at all, but instead simply invalidate the
creating netns pointer when that netns is deleted.

In order to prevent this from happening again, this commit improves the
rough object leak tracking by allowing it to account for created and
destroyed interfaces, aside from just peers and keys. That then makes it
possible to check for the object leak when having two interfaces take a
reference to each others' namespaces.

Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: David S. Miller