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  1. 23 Jan, 2016 20 commits
    • Lukas Czerner's avatar
      ext4: fix potential use after free in __ext4_journal_stop · 3c1c70cf
      Lukas Czerner authored 
      commit 6934da92 upstream.

There is a use-after-free possibility in __ext4_journal_stop() in the
case that we free the handle in the first jbd2_journal_stop() because
we're referencing handle->h_err afterwards. This was introduced in
9705acd6 and it is wrong. Fix it by
storing the handle->h_err value beforehand and avoid referencing
potentially freed handle.

Fixes: 9705acd6Signed-off-by: default avatarLukas Czerner <lczerner@redhat.com>
Reviewed-by: default avatarAndreas Dilger <adilger@dilger.ca>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3c1c70cf
    • Filipe Manana's avatar
      Btrfs: fix race leading to BUG_ON when running delalloc for nodatacow · 389e0b9b
      Filipe Manana authored 
      commit 1d512cb7 upstream.

If we are using the NO_HOLES feature, we have a tiny time window when
running delalloc for a nodatacow inode where we can race with a concurrent
link or xattr add operation leading to a BUG_ON.

This happens because at run_delalloc_nocow() we end up casting a leaf item
of type BTRFS_INODE_[REF|EXTREF]_KEY or of type BTRFS_XATTR_ITEM_KEY to a
file extent item (struct btrfs_file_extent_item) and then analyse its
extent type field, which won't match any of the expected extent types
(values BTRFS_FILE_EXTENT_[REG|PREALLOC|INLINE]) and therefore trigger an
explicit BUG_ON(1).

The following sequence diagram shows how the race happens when running a
no-cow dellaloc range [4K, 8K[ for inode 257 and we have the following
neighbour leafs:

             Leaf X (has N items)                    Leaf Y

 [ ... (257 INODE_ITEM 0) (257 INODE_REF 256) ]  [ (257 EXTENT_DATA 8192), ... ]
              slot N - 2         slot N - 1              slot 0

 (Note the implicit hole for inode 257 regarding the [0, 8K[ range)

       CPU 1                                         CPU 2

 run_dealloc_nocow()
   btrfs_lookup_file_extent()
     --> searches for a key with value
         (257 EXTENT_DATA 4096) in the
         fs/subvol tree
     --> returns us a path with
         path->nodes[0] == leaf X and
         path->slots[0] == N

   because path->slots[0] is >=
   btrfs_header_nritems(leaf X), it
   calls btrfs_next_leaf()

   btrfs_next_leaf()
     --> releases the path

                                              hard link added to our inode,
                                              with key (257 INODE_REF 500)
                                              added to the end of leaf X,
                                              so leaf X now has N + 1 keys

     --> searches for the key
         (257 INODE_REF 256), because
         it was the last key in leaf X
         before it released the path,
         with path->keep_locks set to 1

     --> ends up at leaf X again and
         it verifies that the key
         (257 INODE_REF 256) is no longer
         the last key in the leaf, so it
         returns with path->nodes[0] ==
         leaf X and path->slots[0] == N,
         pointing to the new item with
         key (257 INODE_REF 500)

   the loop iteration of run_dealloc_nocow()
   does not break out the loop and continues
   because the key referenced in the path
   at path->nodes[0] and path->slots[0] is
   for inode 257, its type is < BTRFS_EXTENT_DATA_KEY
   and its offset (500) is less then our delalloc
   range's end (8192)

   the item pointed by the path, an inode reference item,
   is (incorrectly) interpreted as a file extent item and
   we get an invalid extent type, leading to the BUG_ON(1):

   if (extent_type == BTRFS_FILE_EXTENT_REG ||
      extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
       (...)
   } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
       (...)
   } else {
       BUG_ON(1)
   }

The same can happen if a xattr is added concurrently and ends up having
a key with an offset smaller then the delalloc's range end.

So fix this by skipping keys with a type smaller than
BTRFS_EXTENT_DATA_KEY.
Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      389e0b9b
    • Filipe Manana's avatar
      Btrfs: fix race leading to incorrect item deletion when dropping extents · de4306a7
      Filipe Manana authored 
      commit aeafbf84 upstream.

While running a stress test I got the following warning triggered:

  [191627.672810] ------------[ cut here ]------------
  [191627.673949] WARNING: CPU: 8 PID: 8447 at fs/btrfs/file.c:779 __btrfs_drop_extents+0x391/0xa50 [btrfs]()
  (...)
  [191627.701485] Call Trace:
  [191627.702037]  [<ffffffff8145f077>] dump_stack+0x4f/0x7b
  [191627.702992]  [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2
  [191627.704091]  [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb
  [191627.705380]  [<ffffffffa0664499>] ? __btrfs_drop_extents+0x391/0xa50 [btrfs]
  [191627.706637]  [<ffffffff8104b46d>] warn_slowpath_null+0x1a/0x1c
  [191627.707789]  [<ffffffffa0664499>] __btrfs_drop_extents+0x391/0xa50 [btrfs]
  [191627.709155]  [<ffffffff8115663c>] ? cache_alloc_debugcheck_after.isra.32+0x171/0x1d0
  [191627.712444]  [<ffffffff81155007>] ? kmemleak_alloc_recursive.constprop.40+0x16/0x18
  [191627.714162]  [<ffffffffa06570c9>] insert_reserved_file_extent.constprop.40+0x83/0x24e [btrfs]
  [191627.715887]  [<ffffffffa065422b>] ? start_transaction+0x3bb/0x610 [btrfs]
  [191627.717287]  [<ffffffffa065b604>] btrfs_finish_ordered_io+0x273/0x4e2 [btrfs]
  [191627.728865]  [<ffffffffa065b888>] finish_ordered_fn+0x15/0x17 [btrfs]
  [191627.730045]  [<ffffffffa067d688>] normal_work_helper+0x14c/0x32c [btrfs]
  [191627.731256]  [<ffffffffa067d96a>] btrfs_endio_write_helper+0x12/0x14 [btrfs]
  [191627.732661]  [<ffffffff81061119>] process_one_work+0x24c/0x4ae
  [191627.733822]  [<ffffffff810615b0>] worker_thread+0x206/0x2c2
  [191627.734857]  [<ffffffff810613aa>] ? process_scheduled_works+0x2f/0x2f
  [191627.736052]  [<ffffffff810613aa>] ? process_scheduled_works+0x2f/0x2f
  [191627.737349]  [<ffffffff810669a6>] kthread+0xef/0xf7
  [191627.738267]  [<ffffffff810f3b3a>] ? time_hardirqs_on+0x15/0x28
  [191627.739330]  [<ffffffff810668b7>] ? __kthread_parkme+0xad/0xad
  [191627.741976]  [<ffffffff81465592>] ret_from_fork+0x42/0x70
  [191627.743080]  [<ffffffff810668b7>] ? __kthread_parkme+0xad/0xad
  [191627.744206] ---[ end trace bbfddacb7aaada8d ]---

  $ cat -n fs/btrfs/file.c
  691  int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
  (...)
  758                  btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
  759                  if (key.objectid > ino ||
  760                      key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
  761                          break;
  762
  763                  fi = btrfs_item_ptr(leaf, path->slots[0],
  764                                      struct btrfs_file_extent_item);
  765                  extent_type = btrfs_file_extent_type(leaf, fi);
  766
  767                  if (extent_type == BTRFS_FILE_EXTENT_REG ||
  768                      extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
  (...)
  774                  } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
  (...)
  778                  } else {
  779                          WARN_ON(1);
  780                          extent_end = search_start;
  781                  }
  (...)

This happened because the item we were processing did not match a file
extent item (its key type != BTRFS_EXTENT_DATA_KEY), and even on this
case we cast the item to a struct btrfs_file_extent_item pointer and
then find a type field value that does not match any of the expected
values (BTRFS_FILE_EXTENT_[REG|PREALLOC|INLINE]). This scenario happens
due to a tiny time window where a race can happen as exemplified below.
For example, consider the following scenario where we're using the
NO_HOLES feature and we have the following two neighbour leafs:

               Leaf X (has N items)                    Leaf Y

[ ... (257 INODE_ITEM 0) (257 INODE_REF 256) ]  [ (257 EXTENT_DATA 8192), ... ]
          slot N - 2         slot N - 1              slot 0

Our inode 257 has an implicit hole in the range [0, 8K[ (implicit rather
than explicit because NO_HOLES is enabled). Now if our inode has an
ordered extent for the range [4K, 8K[ that is finishing, the following
can happen:

          CPU 1                                       CPU 2

  btrfs_finish_ordered_io()
    insert_reserved_file_extent()
      __btrfs_drop_extents()
         Searches for the key
          (257 EXTENT_DATA 4096) through
          btrfs_lookup_file_extent()

         Key not found and we get a path where
         path->nodes[0] == leaf X and
         path->slots[0] == N

         Because path->slots[0] is >=
         btrfs_header_nritems(leaf X), we call
         btrfs_next_leaf()

         btrfs_next_leaf() releases the path

                                                  inserts key
                                                  (257 INODE_REF 4096)
                                                  at the end of leaf X,
                                                  leaf X now has N + 1 keys,
                                                  and the new key is at
                                                  slot N

         btrfs_next_leaf() searches for
         key (257 INODE_REF 256), with
         path->keep_locks set to 1,
         because it was the last key it
         saw in leaf X

           finds it in leaf X again and
           notices it's no longer the last
           key of the leaf, so it returns 0
           with path->nodes[0] == leaf X and
           path->slots[0] == N (which is now
           < btrfs_header_nritems(leaf X)),
           pointing to the new key
           (257 INODE_REF 4096)

         __btrfs_drop_extents() casts the
         item at path->nodes[0], slot
         path->slots[0], to a struct
         btrfs_file_extent_item - it does
         not skip keys for the target
         inode with a type less than
         BTRFS_EXTENT_DATA_KEY
         (BTRFS_INODE_REF_KEY < BTRFS_EXTENT_DATA_KEY)

         sees a bogus value for the type
         field triggering the WARN_ON in
         the trace shown above, and sets
         extent_end = search_start (4096)

         does the if-then-else logic to
         fixup 0 length extent items created
         by a past bug from hole punching:

           if (extent_end == key.offset &&
               extent_end >= search_start)
               goto delete_extent_item;

         that evaluates to true and it ends
         up deleting the key pointed to by
         path->slots[0], (257 INODE_REF 4096),
         from leaf X

The same could happen for example for a xattr that ends up having a key
with an offset value that matches search_start (very unlikely but not
impossible).

So fix this by ensuring that keys smaller than BTRFS_EXTENT_DATA_KEY are
skipped, never casted to struct btrfs_file_extent_item and never deleted
by accident. Also protect against the unexpected case of getting a key
for a lower inode number by skipping that key and issuing a warning.
Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      de4306a7
    • Eric Dumazet's avatar
      ipv6: sctp: implement sctp_v6_destroy_sock() · a8fa15f0
      Eric Dumazet authored 
      [ Upstream commit 602dd62d ]

Dmitry Vyukov reported a memory leak using IPV6 SCTP sockets.

We need to call inet6_destroy_sock() to properly release
inet6 specific fields.
Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a8fa15f0
    • Michal Kubeček's avatar
      ipv6: distinguish frag queues by device for multicast and link-local packets · f4ce575c
      Michal Kubeček authored 
      [ Upstream commit 264640fc ]

If a fragmented multicast packet is received on an ethernet device which
has an active macvlan on top of it, each fragment is duplicated and
received both on the underlying device and the macvlan. If some
fragments for macvlan are processed before the whole packet for the
underlying device is reassembled, the "overlapping fragments" test in
ip6_frag_queue() discards the whole fragment queue.

To resolve this, add device ifindex to the search key and require it to
match reassembling multicast packets and packets to link-local
addresses.

Note: similar patch has been already submitted by Yoshifuji Hideaki in

  http://patchwork.ozlabs.org/patch/220979/

but got lost and forgotten for some reason.
Signed-off-by: default avatarMichal Kubecek <mkubecek@suse.cz>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f4ce575c
    • Aaro Koskinen's avatar
      broadcom: fix PHY_ID_BCM5481 entry in the id table · ad7a4964
      Aaro Koskinen authored 
      [ Upstream commit 3c25a860 ]

Commit fcb26ec5 ("broadcom: move all PHY_ID's to header")
updated broadcom_tbl to use PHY_IDs, but incorrectly replaced 0x0143bca0
with PHY_ID_BCM5482 (making a duplicate entry, and completely omitting
the original). Fix that.

Fixes: fcb26ec5 ("broadcom: move all PHY_ID's to header")
Signed-off-by: default avatarAaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ad7a4964
    • Nikolay Aleksandrov's avatar
      net: ip6mr: fix static mfc/dev leaks on table destruction · 10a72b76
      Nikolay Aleksandrov authored 
      [ Upstream commit 4c698046 ]

Similar to ipv4, when destroying an mrt table the static mfc entries and
the static devices are kept, which leads to devices that can never be
destroyed (because of refcnt taken) and leaked memory. Make sure that
everything is cleaned up on netns destruction.

Fixes: 8229efda ("netns: ip6mr: enable namespace support in ipv6 multicast forwarding code")
CC: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: default avatarNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: default avatarCong Wang <cwang@twopensource.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      10a72b76
    • Nikolay Aleksandrov's avatar
      net: ipmr: fix static mfc/dev leaks on table destruction · 207c03d6
      Nikolay Aleksandrov authored 
      [ Upstream commit 0e615e96 ]

When destroying an mrt table the static mfc entries and the static
devices are kept, which leads to devices that can never be destroyed
(because of refcnt taken) and leaked memory, for example:
unreferenced object 0xffff880034c144c0 (size 192):
  comm "mfc-broken", pid 4777, jiffies 4320349055 (age 46001.964s)
  hex dump (first 32 bytes):
    98 53 f0 34 00 88 ff ff 98 53 f0 34 00 88 ff ff  .S.4.....S.4....
    ef 0a 0a 14 01 02 03 04 00 00 00 00 01 00 00 00  ................
  backtrace:
    [<ffffffff815c1b9e>] kmemleak_alloc+0x4e/0xb0
    [<ffffffff811ea6e0>] kmem_cache_alloc+0x190/0x300
    [<ffffffff815931cb>] ip_mroute_setsockopt+0x5cb/0x910
    [<ffffffff8153d575>] do_ip_setsockopt.isra.11+0x105/0xff0
    [<ffffffff8153e490>] ip_setsockopt+0x30/0xa0
    [<ffffffff81564e13>] raw_setsockopt+0x33/0x90
    [<ffffffff814d1e14>] sock_common_setsockopt+0x14/0x20
    [<ffffffff814d0b51>] SyS_setsockopt+0x71/0xc0
    [<ffffffff815cdbf6>] entry_SYSCALL_64_fastpath+0x16/0x7a
    [<ffffffffffffffff>] 0xffffffffffffffff

Make sure that everything is cleaned on netns destruction.
Signed-off-by: default avatarNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: default avatarCong Wang <cwang@twopensource.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      207c03d6
    • Daniel Borkmann's avatar
      net, scm: fix PaX detected msg_controllen overflow in scm_detach_fds · c35d6700
      Daniel Borkmann authored 
      [ Upstream commit 6900317f ]

David and HacKurx reported a following/similar size overflow triggered
in a grsecurity kernel, thanks to PaX's gcc size overflow plugin:

(Already fixed in later grsecurity versions by Brad and PaX Team.)

[ 1002.296137] PAX: size overflow detected in function scm_detach_fds net/core/scm.c:314
               cicus.202_127 min, count: 4, decl: msg_controllen; num: 0; context: msghdr;
[ 1002.296145] CPU: 0 PID: 3685 Comm: scm_rights_recv Not tainted 4.2.3-grsec+ #7
[ 1002.296149] Hardware name: Apple Inc. MacBookAir5,1/Mac-66F35F19FE2A0D05, [...]
[ 1002.296153]  ffffffff81c27366 0000000000000000 ffffffff81c27375 ffffc90007843aa8
[ 1002.296162]  ffffffff818129ba 0000000000000000 ffffffff81c27366 ffffc90007843ad8
[ 1002.296169]  ffffffff8121f838 fffffffffffffffc fffffffffffffffc ffffc90007843e60
[ 1002.296176] Call Trace:
[ 1002.296190]  [<ffffffff818129ba>] dump_stack+0x45/0x57
[ 1002.296200]  [<ffffffff8121f838>] report_size_overflow+0x38/0x60
[ 1002.296209]  [<ffffffff816a979e>] scm_detach_fds+0x2ce/0x300
[ 1002.296220]  [<ffffffff81791899>] unix_stream_read_generic+0x609/0x930
[ 1002.296228]  [<ffffffff81791c9f>] unix_stream_recvmsg+0x4f/0x60
[ 1002.296236]  [<ffffffff8178dc00>] ? unix_set_peek_off+0x50/0x50
[ 1002.296243]  [<ffffffff8168fac7>] sock_recvmsg+0x47/0x60
[ 1002.296248]  [<ffffffff81691522>] ___sys_recvmsg+0xe2/0x1e0
[ 1002.296257]  [<ffffffff81693496>] __sys_recvmsg+0x46/0x80
[ 1002.296263]  [<ffffffff816934fc>] SyS_recvmsg+0x2c/0x40
[ 1002.296271]  [<ffffffff8181a3ab>] entry_SYSCALL_64_fastpath+0x12/0x85

Further investigation showed that this can happen when an *odd* number of
fds are being passed over AF_UNIX sockets.

In these cases CMSG_LEN(i * sizeof(int)) and CMSG_SPACE(i * sizeof(int)),
where i is the number of successfully passed fds, differ by 4 bytes due
to the extra CMSG_ALIGN() padding in CMSG_SPACE() to an 8 byte boundary
on 64 bit. The padding is used to align subsequent cmsg headers in the
control buffer.

When the control buffer passed in from the receiver side *lacks* these 4
bytes (e.g. due to buggy/wrong API usage), then msg->msg_controllen will
overflow in scm_detach_fds():

  int cmlen = CMSG_LEN(i * sizeof(int));  <--- cmlen w/o tail-padding
  err = put_user(SOL_SOCKET, &cm->cmsg_level);
  if (!err)
    err = put_user(SCM_RIGHTS, &cm->cmsg_type);
  if (!err)
    err = put_user(cmlen, &cm->cmsg_len);
  if (!err) {
    cmlen = CMSG_SPACE(i * sizeof(int));  <--- cmlen w/ 4 byte extra tail-padding
    msg->msg_control += cmlen;
    msg->msg_controllen -= cmlen;         <--- iff no tail-padding space here ...
  }                                            ... wrap-around

F.e. it will wrap to a length of 18446744073709551612 bytes in case the
receiver passed in msg->msg_controllen of 20 bytes, and the sender
properly transferred 1 fd to the receiver, so that its CMSG_LEN results
in 20 bytes and CMSG_SPACE in 24 bytes.

In case of MSG_CMSG_COMPAT (scm_detach_fds_compat()), I haven't seen an
issue in my tests as alignment seems always on 4 byte boundary. Same
should be in case of native 32 bit, where we end up with 4 byte boundaries
as well.

In practice, passing msg->msg_controllen of 20 to recvmsg() while receiving
a single fd would mean that on successful return, msg->msg_controllen is
being set by the kernel to 24 bytes instead, thus more than the input
buffer advertised. It could f.e. become an issue if such application later
on zeroes or copies the control buffer based on the returned msg->msg_controllen
elsewhere.

Maximum number of fds we can send is a hard upper limit SCM_MAX_FD (253).

Going over the code, it seems like msg->msg_controllen is not being read
after scm_detach_fds() in scm_recv() anymore by the kernel, good!

Relevant recvmsg() handler are unix_dgram_recvmsg() (unix_seqpacket_recvmsg())
and unix_stream_recvmsg(). Both return back to their recvmsg() caller,
and ___sys_recvmsg() places the updated length, that is, new msg_control -
old msg_control pointer into msg->msg_controllen (hence the 24 bytes seen
in the example).

Long time ago, Wei Yongjun fixed something related in commit 1ac70e7a
("[NET]: Fix function put_cmsg() which may cause usr application memory
overflow").

RFC3542, section 20.2. says:

  The fields shown as "XX" are possible padding, between the cmsghdr
  structure and the data, and between the data and the next cmsghdr
  structure, if required by the implementation. While sending an
  application may or may not include padding at the end of last
  ancillary data in msg_controllen and implementations must accept both
  as valid. On receiving a portable application must provide space for
  padding at the end of the last ancillary data as implementations may
  copy out the padding at the end of the control message buffer and
  include it in the received msg_controllen. When recvmsg() is called
  if msg_controllen is too small for all the ancillary data items
  including any trailing padding after the last item an implementation
  may set MSG_CTRUNC.

Since we didn't place MSG_CTRUNC for already quite a long time, just do
the same as in 1ac70e7a to avoid an overflow.

Btw, even man-page author got this wrong :/ See db939c9b26e9 ("cmsg.3: Fix
error in SCM_RIGHTS code sample"). Some people must have copied this (?),
thus it got triggered in the wild (reported several times during boot by
David and HacKurx).

No Fixes tag this time as pre 2002 (that is, pre history tree).
Reported-by: default avatarDavid Sterba <dave@jikos.cz>
Reported-by: default avatarHacKurx <hackurx@gmail.com>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: Eric Dumazet <edumazet@google.com>
Reviewed-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c35d6700
    • Eric Dumazet's avatar
      tcp: initialize tp->copied_seq in case of cross SYN connection · d24edcc3
      Eric Dumazet authored 
      [ Upstream commit 142a2e7e ]

Dmitry provided a syzkaller (http://github.com/google/syzkaller)
generated program that triggers the WARNING at
net/ipv4/tcp.c:1729 in tcp_recvmsg() :

WARN_ON(tp->copied_seq != tp->rcv_nxt &&
        !(flags & (MSG_PEEK | MSG_TRUNC)));

His program is specifically attempting a Cross SYN TCP exchange,
that we support (for the pleasure of hackers ?), but it looks we
lack proper tcp->copied_seq initialization.

Thanks again Dmitry for your report and testings.
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
Tested-by: default avatarDmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d24edcc3
    • Eric Dumazet's avatar
      tcp: md5: fix lockdep annotation · ab3689c8
      Eric Dumazet authored 
      [ Upstream commit 1b8e6a01 ]

When a passive TCP is created, we eventually call tcp_md5_do_add()
with sk pointing to the child. It is not owner by the user yet (we
will add this socket into listener accept queue a bit later anyway)

But we do own the spinlock, so amend the lockdep annotation to avoid
following splat :

[ 8451.090932] net/ipv4/tcp_ipv4.c:923 suspicious rcu_dereference_protected() usage!
[ 8451.090932]
[ 8451.090932] other info that might help us debug this:
[ 8451.090932]
[ 8451.090934]
[ 8451.090934] rcu_scheduler_active = 1, debug_locks = 1
[ 8451.090936] 3 locks held by socket_sockopt_/214795:
[ 8451.090936]  #0:  (rcu_read_lock){.+.+..}, at: [<ffffffff855c6ac1>] __netif_receive_skb_core+0x151/0xe90
[ 8451.090947]  #1:  (rcu_read_lock){.+.+..}, at: [<ffffffff85618143>] ip_local_deliver_finish+0x43/0x2b0
[ 8451.090952]  #2:  (slock-AF_INET){+.-...}, at: [<ffffffff855acda5>] sk_clone_lock+0x1c5/0x500
[ 8451.090958]
[ 8451.090958] stack backtrace:
[ 8451.090960] CPU: 7 PID: 214795 Comm: socket_sockopt_

[ 8451.091215] Call Trace:
[ 8451.091216]  <IRQ>  [<ffffffff856fb29c>] dump_stack+0x55/0x76
[ 8451.091229]  [<ffffffff85123b5b>] lockdep_rcu_suspicious+0xeb/0x110
[ 8451.091235]  [<ffffffff8564544f>] tcp_md5_do_add+0x1bf/0x1e0
[ 8451.091239]  [<ffffffff85645751>] tcp_v4_syn_recv_sock+0x1f1/0x4c0
[ 8451.091242]  [<ffffffff85642b27>] ? tcp_v4_md5_hash_skb+0x167/0x190
[ 8451.091246]  [<ffffffff85647c78>] tcp_check_req+0x3c8/0x500
[ 8451.091249]  [<ffffffff856451ae>] ? tcp_v4_inbound_md5_hash+0x11e/0x190
[ 8451.091253]  [<ffffffff85647170>] tcp_v4_rcv+0x3c0/0x9f0
[ 8451.091256]  [<ffffffff85618143>] ? ip_local_deliver_finish+0x43/0x2b0
[ 8451.091260]  [<ffffffff856181b6>] ip_local_deliver_finish+0xb6/0x2b0
[ 8451.091263]  [<ffffffff85618143>] ? ip_local_deliver_finish+0x43/0x2b0
[ 8451.091267]  [<ffffffff85618d38>] ip_local_deliver+0x48/0x80
[ 8451.091270]  [<ffffffff85618510>] ip_rcv_finish+0x160/0x700
[ 8451.091273]  [<ffffffff8561900e>] ip_rcv+0x29e/0x3d0
[ 8451.091277]  [<ffffffff855c74b7>] __netif_receive_skb_core+0xb47/0xe90

Fixes: a8afca03 ("tcp: md5: protects md5sig_info with RCU")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reported-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ab3689c8
    • Bjørn Mork's avatar
      net: qmi_wwan: add XS Stick W100-2 from 4G Systems · e9ec6742
      Bjørn Mork authored 
      [ Upstream commit 68242a5a ]

Thomas reports
"
4gsystems sells two total different LTE-surfsticks under the same name.
..
The newer version of XS Stick W100 is from "omega"
..
Under windows the driver switches to the same ID, and uses MI03\6 for
network and MI01\6 for modem.
..
echo "1c9e 9b01" > /sys/bus/usb/drivers/qmi_wwan/new_id
echo "1c9e 9b01" > /sys/bus/usb-serial/drivers/option1/new_id

T:  Bus=01 Lev=01 Prnt=01 Port=03 Cnt=01 Dev#=  4 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=1c9e ProdID=9b01 Rev=02.32
S:  Manufacturer=USB Modem
S:  Product=USB Modem
S:  SerialNumber=
C:  #Ifs= 5 Cfg#= 1 Atr=80 MxPwr=500mA
I:  If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=option
I:  If#= 1 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=option
I:  If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=option
I:  If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=qmi_wwan
I:  If#= 4 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage

Now all important things are there:

wwp0s29f7u2i3 (net), ttyUSB2 (at), cdc-wdm0 (qmi), ttyUSB1 (at)

There is also ttyUSB0, but it is not usable, at least not for at.

The device works well with qmi and ModemManager-NetworkManager.
"
Reported-by: default avatarThomas Schäfer <tschaefer@t-online.de>
Signed-off-by: default avatarBjørn Mork <bjorn@mork.no>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e9ec6742
    • Neil Horman's avatar
      snmp: Remove duplicate OUTMCAST stat increment · c32a5063
      Neil Horman authored 
      [ Upstream commit 41033f02 ]

the OUTMCAST stat is double incremented, getting bumped once in the mcast code
itself, and again in the common ip output path.  Remove the mcast bump, as its
not needed

Validated by the reporter, with good results
Signed-off-by: default avatarNeil Horman <nhorman@tuxdriver.com>
Reported-by: default avatarClaus Jensen <claus.jensen@microsemi.com>
CC: Claus Jensen <claus.jensen@microsemi.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c32a5063
    • Jason A. Donenfeld's avatar
      ip_tunnel: disable preemption when updating per-cpu tstats · f4f4b092
      Jason A. Donenfeld authored 
      [ Upstream commit b4fe85f9 ]

Drivers like vxlan use the recently introduced
udp_tunnel_xmit_skb/udp_tunnel6_xmit_skb APIs. udp_tunnel6_xmit_skb
makes use of ip6tunnel_xmit, and ip6tunnel_xmit, after sending the
packet, updates the struct stats using the usual
u64_stats_update_begin/end calls on this_cpu_ptr(dev->tstats).
udp_tunnel_xmit_skb makes use of iptunnel_xmit, which doesn't touch
tstats, so drivers like vxlan, immediately after, call
iptunnel_xmit_stats, which does the same thing - calls
u64_stats_update_begin/end on this_cpu_ptr(dev->tstats).

While vxlan is probably fine (I don't know?), calling a similar function
from, say, an unbound workqueue, on a fully preemptable kernel causes
real issues:

[  188.434537] BUG: using smp_processor_id() in preemptible [00000000] code: kworker/u8:0/6
[  188.435579] caller is debug_smp_processor_id+0x17/0x20
[  188.435583] CPU: 0 PID: 6 Comm: kworker/u8:0 Not tainted 4.2.6 #2
[  188.435607] Call Trace:
[  188.435611]  [<ffffffff8234e936>] dump_stack+0x4f/0x7b
[  188.435615]  [<ffffffff81915f3d>] check_preemption_disabled+0x19d/0x1c0
[  188.435619]  [<ffffffff81915f77>] debug_smp_processor_id+0x17/0x20

The solution would be to protect the whole
this_cpu_ptr(dev->tstats)/u64_stats_update_begin/end blocks with
disabling preemption and then reenabling it.
Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f4f4b092
    • lucien's avatar
      sctp: translate host order to network order when setting a hmacid · a286e9c0
      lucien authored 
      [ Upstream commit ed5a377d ]

now sctp auth cannot work well when setting a hmacid manually, which
is caused by that we didn't use the network order for hmacid, so fix
it by adding the transformation in sctp_auth_ep_set_hmacs.

even we set hmacid with the network order in userspace, it still
can't work, because of this condition in sctp_auth_ep_set_hmacs():

		if (id > SCTP_AUTH_HMAC_ID_MAX)
			return -EOPNOTSUPP;

so this wasn't working before and thus it won't break compatibility.

Fixes: 65b07e5d ("[SCTP]: API updates to suport SCTP-AUTH extensions.")
Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
Signed-off-by: default avatarMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: default avatarNeil Horman <nhorman@tuxdriver.com>
Acked-by: default avatarVlad Yasevich <vyasevich@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a286e9c0
    • Daniel Borkmann's avatar
      packet: infer protocol from ethernet header if unset · de23f6a7
      Daniel Borkmann authored 
      [ Upstream commit c72219b7 ]

In case no struct sockaddr_ll has been passed to packet
socket's sendmsg() when doing a TX_RING flush run, then
skb->protocol is set to po->num instead, which is the protocol
passed via socket(2)/bind(2).

Applications only xmitting can go the path of allocating the
socket as socket(PF_PACKET, <mode>, 0) and do a bind(2) on the
TX_RING with sll_protocol of 0. That way, register_prot_hook()
is neither called on creation nor on bind time, which saves
cycles when there's no interest in capturing anyway.

That leaves us however with po->num 0 instead and therefore
the TX_RING flush run sets skb->protocol to 0 as well. Eric
reported that this leads to problems when using tools like
trafgen over bonding device. I.e. the bonding's hash function
could invoke the kernel's flow dissector, which depends on
skb->protocol being properly set. In the current situation, all
the traffic is then directed to a single slave.

Fix it up by inferring skb->protocol from the Ethernet header
when not set and we have ARPHRD_ETHER device type. This is only
done in case of SOCK_RAW and where we have a dev->hard_header_len
length. In case of ARPHRD_ETHER devices, this is guaranteed to
cover ETH_HLEN, and therefore being accessed on the skb after
the skb_store_bits().
Reported-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      de23f6a7
    • Daniel Borkmann's avatar
      packet: always probe for transport header · c8f0bbc0
      Daniel Borkmann authored 
      [ Upstream commit 8fd6c80d ]

We concluded that the skb_probe_transport_header() should better be
called unconditionally. Avoiding the call into the flow dissector has
also not really much to do with the direct xmit mode.

While it seems that only virtio_net code makes use of GSO from non
RX/TX ring packet socket paths, we should probe for a transport header
nevertheless before they hit devices.

Reference: http://thread.gmane.org/gmane.linux.network/386173/Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c8f0bbc0
    • Daniel Borkmann's avatar
      packet: do skb_probe_transport_header when we actually have data · 0fd58003
      Daniel Borkmann authored 
      [ Upstream commit efdfa2f7 ]

In tpacket_fill_skb() commit c1aad275 ("packet: set transport
header before doing xmit") and later on 40893fd0 ("net: switch
to use skb_probe_transport_header()") was probing for a transport
header on the skb from a ring buffer slot, but at a time, where
the skb has _not even_ been filled with data yet. So that call into
the flow dissector is pretty useless. Lets do it after we've set
up the skb frags.

Fixes: c1aad275 ("packet: set transport header before doing xmit")
Reported-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0fd58003
    • Kamal Mostafa's avatar
      tools/net: Use include/uapi with __EXPORTED_HEADERS__ · 4db32ea3
      Kamal Mostafa authored 
      [ Upstream commit d7475de5 ]

Use the local uapi headers to keep in sync with "recently" added #define's
(e.g. SKF_AD_VLAN_TPID).  Refactored CFLAGS, and bpf_asm doesn't need -I.

Fixes: 3f356385 ("filter: bpf_asm: add minimal bpf asm tool")
Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4db32ea3
    • Rainer Weikusat's avatar
      unix: avoid use-after-free in ep_remove_wait_queue · 9d054f57
      Rainer Weikusat authored 
      [ Upstream commit 7d267278 ]

Rainer Weikusat <rweikusat@mobileactivedefense.com> writes:
An AF_UNIX datagram socket being the client in an n:1 association with
some server socket is only allowed to send messages to the server if the
receive queue of this socket contains at most sk_max_ack_backlog
datagrams. This implies that prospective writers might be forced to go
to sleep despite none of the message presently enqueued on the server
receive queue were sent by them. In order to ensure that these will be
woken up once space becomes again available, the present unix_dgram_poll
routine does a second sock_poll_wait call with the peer_wait wait queue
of the server socket as queue argument (unix_dgram_recvmsg does a wake
up on this queue after a datagram was received). This is inherently
problematic because the server socket is only guaranteed to remain alive
for as long as the client still holds a reference to it. In case the
connection is dissolved via connect or by the dead peer detection logic
in unix_dgram_sendmsg, the server socket may be freed despite "the
polling mechanism" (in particular, epoll) still has a pointer to the
corresponding peer_wait queue. There's no way to forcibly deregister a
wait queue with epoll.

Based on an idea by Jason Baron, the patch below changes the code such
that a wait_queue_t belonging to the client socket is enqueued on the
peer_wait queue of the server whenever the peer receive queue full
condition is detected by either a sendmsg or a poll. A wake up on the
peer queue is then relayed to the ordinary wait queue of the client
socket via wake function. The connection to the peer wait queue is again
dissolved if either a wake up is about to be relayed or the client
socket reconnects or a dead peer is detected or the client socket is
itself closed. This enables removing the second sock_poll_wait from
unix_dgram_poll, thus avoiding the use-after-free, while still ensuring
that no blocked writer sleeps forever.
Signed-off-by: default avatarRainer Weikusat <rweikusat@mobileactivedefense.com>
Fixes: ec0d215f ("af_unix: fix 'poll for write'/connected DGRAM sockets")
Reviewed-by: default avatarJason Baron <jbaron@akamai.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9d054f57
  3. 09 Dec, 2015 20 commits
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