The calculation of RTTVAR involves the subtraction of two unsigned
numbers which
may causes rollover and results in very high values of RTTVAR when RTT > SRTT.
With this patch it is possible to set RTOmin = 1 to get the minimum of RTO at
4 times the clock granularity.

Change Notes:

v2)
        *Replaced abs() by abs64() and long by __s64, changed patch
description.

Signed-off-by: Christian Schoch <e0326715@student.tuwien.ac.at>
CC: Vlad Yasevich <vyasevich@gmail.com>
CC: Sridhar Samudrala <sri@us.ibm.com>
CC: Neil Horman <nhorman@tuxdriver.com>
CC: linux-sctp@vger.kernel.org
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Consider the following program, that sets the second argument to the
sendto() syscall incorrectly:

 #include <string.h>
 #include <arpa/inet.h>
 #include <sys/socket.h>

 int main(void)
 {
         int fd;
         struct sockaddr_in sa;

         fd = socket(AF_INET, SOCK_STREAM, 132 /*IPPROTO_SCTP*/);
         if (fd < 0)
                 return 1;

         memset(&sa, 0, sizeof(sa));
         sa.sin_family = AF_INET;
         sa.sin_addr.s_addr = inet_addr("127.0.0.1");
         sa.sin_port = htons(11111);

         sendto(fd, NULL, 1, 0, (struct sockaddr *)&sa, sizeof(sa));

         return 0;
 }

We get -ENOMEM:

 $ strace -e sendto ./demo
 sendto(3, NULL, 1, 0, {sa_family=AF_INET, sin_port=htons(11111), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 ENOMEM (Cannot allocate memory)

Propagate the error code from sctp_user_addto_chunk(), so that we will
tell user space what actually went wrong:

 $ strace -e sendto ./demo
 sendto(3, NULL, 1, 0, {sa_family=AF_INET, sin_port=htons(11111), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 EFAULT (Bad address)

Noticed while running Trinity (the syscall fuzzer).

Signed-off-by: Tommi Rantala <tt.rantala@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Trinity (the syscall fuzzer) discovered a memory leak in SCTP,
reproducible e.g. with the sendto() syscall by passing invalid
user space pointer in the second argument:

 #include <string.h>
 #include <arpa/inet.h>
 #include <sys/socket.h>

 int main(void)
 {
         int fd;
         struct sockaddr_in sa;

         fd = socket(AF_INET, SOCK_STREAM, 132 /*IPPROTO_SCTP*/);
         if (fd < 0)
                 return 1;

         memset(&sa, 0, sizeof(sa));
         sa.sin_family = AF_INET;
         sa.sin_addr.s_addr = inet_addr("127.0.0.1");
         sa.sin_port = htons(11111);

         sendto(fd, NULL, 1, 0, (struct sockaddr *)&sa, sizeof(sa));

         return 0;
 }

As far as I can tell, the leak has been around since ~2003.

Signed-off-by: Tommi Rantala <tt.rantala@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 13d782f ("sctp: Make the proc files per network namespace.")
changed the /proc/net/sctp/ struct file_operations opener functions to
use single_open_net() and seq_open_net().

Avoid leaking memory by using single_release_net() and seq_release_net()
as the release functions.

Discovered with Trinity (the syscall fuzzer).

Signed-off-by: Tommi Rantala <tt.rantala@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Correct spelling typo in net/sctp/socket.c

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Bug introduced by commit edfee0339e681a784ebacec7e8c2dc97dc6d2839
(sctp: check src addr when processing SACK to update transport state)

Signed-off-by: Zijie Pan <zijie.pan@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull networking changes from David Miller:
 "The most important bit in here is the fix for input route caching from
  Eric Dumazet, it's a shame we couldn't fully analyze this in time for
  3.6 as it's a 3.6 regression introduced by the routing cache removal.

  Anyways, will send quickly to -stable after you pull this in.

  Other changes of note:

   1) Fix lockdep splats in team and bonding, from Eric Dumazet.

   2) IPV6 adds link local route even when there is no link local
      address, from Nicolas Dichtel.

   3) Fix ixgbe PTP implementation, from Jacob Keller.

   4) Fix excessive stack usage in cxgb4 driver, from Vipul Pandya.

   5) MAC length computed improperly in VLAN demux, from Antonio
      Quartulli."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits)
  ipv6: release reference of ip6_null_entry's dst entry in __ip6_del_rt
  Remove noisy printks from llcp_sock_connect
  tipc: prevent dropped connections due to rcvbuf overflow
  silence some noisy printks in irda
  team: set qdisc_tx_busylock to avoid LOCKDEP splat
  bonding: set qdisc_tx_busylock to avoid LOCKDEP splat
  sctp: check src addr when processing SACK to update transport state
  sctp: fix a typo in prototype of __sctp_rcv_lookup()
  ipv4: add a fib_type to fib_info
  can: mpc5xxx_can: fix section type conflict
  can: peak_pcmcia: fix error return code
  can: peak_pci: fix error return code
  cxgb4: Fix build error due to missing linux/vmalloc.h include.
  bnx2x: fix ring size for 10G functions
  cxgb4: Dynamically allocate memory in t4_memory_rw() and get_vpd_params()
  ixgbe: add support for X540-AT1
  ixgbe: fix poll loop for FDIRCTRL.INIT_DONE bit
  ixgbe: fix PTP ethtool timestamping function
  ixgbe: (PTP) Fix PPS interrupt code
  ixgbe: Fix PTP X540 SDP alignment code for PPS signal
  ...

Suppose we have an SCTP connection with two paths. After connection is
established, path1 is not available, thus this path is marked as inactive. Then
traffic goes through path2, but for some reasons packets are delayed (after
rto.max). Because packets are delayed, the retransmit mechanism will switch
again to path1. At this time, we receive a delayed SACK from path2. When we
update the state of the path in sctp_check_transmitted(), we do not take into
account the source address of the SACK, hence we update the wrong path.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Just to avoid confusion when people only reads this prototype.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull vfs update from Al Viro:

 - big one - consolidation of descriptor-related logics; almost all of
   that is moved to fs/file.c

   (BTW, I'm seriously tempted to rename the result to fd.c.  As it is,
   we have a situation when file_table.c is about handling of struct
   file and file.c is about handling of descriptor tables; the reasons
   are historical - file_table.c used to be about a static array of
   struct file we used to have way back).

   A lot of stray ends got cleaned up and converted to saner primitives,
   disgusting mess in android/binder.c is still disgusting, but at least
   doesn't poke so much in descriptor table guts anymore.  A bunch of
   relatively minor races got fixed in process, plus an ext4 struct file
   leak.

 - related thing - fget_light() partially unuglified; see fdget() in
   there (and yes, it generates the code as good as we used to have).

 - also related - bits of Cyrill's procfs stuff that got entangled into
   that work; _not_ all of it, just the initial move to fs/proc/fd.c and
   switch of fdinfo to seq_file.

 - Alex's fs/coredump.c spiltoff - the same story, had been easier to
   take that commit than mess with conflicts.  The rest is a separate
   pile, this was just a mechanical code movement.

 - a few misc patches all over the place.  Not all for this cycle,
   there'll be more (and quite a few currently sit in akpm's tree)."

Fix up trivial conflicts in the android binder driver, and some fairly
simple conflicts due to two different changes to the sock_alloc_file()
interface ("take descriptor handling from sock_alloc_file() to callers"
vs "net: Providing protocol type via system.sockprotoname xattr of
/proc/PID/fd entries" adding a dentry name to the socket)

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits)
  MAX_LFS_FILESIZE should be a loff_t
  compat: fs: Generic compat_sys_sendfile implementation
  fs: push rcu_barrier() from deactivate_locked_super() to filesystems
  btrfs: reada_extent doesn't need kref for refcount
  coredump: move core dump functionality into its own file
  coredump: prevent double-free on an error path in core dumper
  usb/gadget: fix misannotations
  fcntl: fix misannotations
  ceph: don't abuse d_delete() on failure exits
  hypfs: ->d_parent is never NULL or negative
  vfs: delete surplus inode NULL check
  switch simple cases of fget_light to fdget
  new helpers: fdget()/fdput()
  switch o2hb_region_dev_write() to fget_light()
  proc_map_files_readdir(): don't bother with grabbing files
  make get_file() return its argument
  vhost_set_vring(): turn pollstart/pollstop into bool
  switch prctl_set_mm_exe_file() to fget_light()
  switch xfs_find_handle() to fget_light()
  switch xfs_swapext() to fget_light()
  ...