Commit Graph

44 Commits

Author SHA1 Message Date
Tejun Heo
2a56a1fec2 net: wrap sock->sk_cgrp_prioidx and ->sk_classid inside a struct
Introduce sock->sk_cgrp_data which is a struct sock_cgroup_data.
->sk_cgroup_prioidx and ->sk_classid are moved into it.  The struct
and its accessors are defined in cgroup-defs.h.  This is to prepare
for overloading the fields with a cgroup pointer.

This patch mostly performs equivalent conversions but the followings
are noteworthy.

* Equality test before updating classid is removed from
  sock_update_classid().  This shouldn't make any noticeable
  difference and a similar test will be implemented on the helper side
  later.

* sock_update_netprioidx() now takes struct sock_cgroup_data and can
  be moved to netprio_cgroup.h without causing include dependency
  loop.  Moved.

* The dummy version of sock_update_netprioidx() converted to a static
  inline function while at it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-08 22:02:33 -05:00
Daniel Borkmann
6900317f5e net, scm: fix PaX detected msg_controllen overflow in scm_detach_fds
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 1ac70e7ad2
("[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 1ac70e7ad2 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: David Sterba <dave@jikos.cz>
Reported-by: HacKurx <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: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-22 20:34:58 -05:00
Gu Zheng
f95b414edb net: introduce helper macro for_each_cmsghdr
Introduce helper macro for_each_cmsghdr as a wrapper of the enumerating
cmsghdr from msghdr, just cleanup.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-10 22:41:55 -05:00
Linus Torvalds
c7c4591db6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace changes from Eric Biederman:
 "This is an assorted mishmash of small cleanups, enhancements and bug
  fixes.

  The major theme is user namespace mount restrictions.  nsown_capable
  is killed as it encourages not thinking about details that need to be
  considered.  A very hard to hit pid namespace exiting bug was finally
  tracked and fixed.  A couple of cleanups to the basic namespace
  infrastructure.

  Finally there is an enhancement that makes per user namespace
  capabilities usable as capabilities, and an enhancement that allows
  the per userns root to nice other processes in the user namespace"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  userns:  Kill nsown_capable it makes the wrong thing easy
  capabilities: allow nice if we are privileged
  pidns: Don't have unshare(CLONE_NEWPID) imply CLONE_THREAD
  userns: Allow PR_CAPBSET_DROP in a user namespace.
  namespaces: Simplify copy_namespaces so it is clear what is going on.
  pidns: Fix hang in zap_pid_ns_processes by sending a potentially extra wakeup
  sysfs: Restrict mounting sysfs
  userns: Better restrictions on when proc and sysfs can be mounted
  vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces
  kernel/nsproxy.c: Improving a snippet of code.
  proc: Restrict mounting the proc filesystem
  vfs: Lock in place mounts from more privileged users
2013-09-07 14:35:32 -07:00
Eric W. Biederman
c7b96acf14 userns: Kill nsown_capable it makes the wrong thing easy
nsown_capable is a special case of ns_capable essentially for just CAP_SETUID and
CAP_SETGID.  For the existing users it doesn't noticably simplify things and
from the suggested patches I have seen it encourages people to do the wrong
thing.  So remove nsown_capable.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-08-30 23:44:11 -07:00
Andy Lutomirski
d661684cf6 net: Check the correct namespace when spoofing pid over SCM_RIGHTS
This is a security bug.

The follow-up will fix nsproxy to discourage this type of issue from
happening again.

Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-27 13:52:52 -04:00
Zefan Li
6ffd464102 netprio_cgroup: remove task_struct parameter from sock_update_netprio()
The callers always pass current to sock_update_netprio().

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-09 13:19:37 -04:00
Zefan Li
211d2f97e9 cls_cgroup: remove task_struct parameter from sock_update_classid()
The callers always pass current to sock_update_classid().

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-09 13:19:35 -04:00
Eric W. Biederman
6b0ee8c036 scm: Stop passing struct cred
Now that uids and gids are completely encapsulated in kuid_t
and kgid_t we no longer need to pass struct cred which allowed
us to test both the uid and the user namespace for equality.

Passing struct cred potentially allows us to pass the entire group
list as BSD does but I don't believe the cost of cache line misses
justifies retaining code for a future potential application.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-07 18:58:55 -04:00
Eric W. Biederman
92f28d973c scm: Require CAP_SYS_ADMIN over the current pidns to spoof pids.
Don't allow spoofing pids over unix domain sockets in the corner
cases where a user has created a user namespace but has not yet
created a pid namespace.

Cc: stable@vger.kernel.org
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-17 17:16:16 -07:00
Daniel Wagner
d84295067f net: net_cls: fd passed in SCM_RIGHTS datagram not set correctly
Commit 6a328d8c6f changed the update
logic for the socket but it does not update the SCM_RIGHTS update
as well. This patch is based on the net_prio fix commit

48a87cc26c

    net: netprio: fd passed in SCM_RIGHTS datagram not set correctly

    A socket fd passed in a SCM_RIGHTS datagram was not getting
    updated with the new tasks cgrp prioidx. This leaves IO on
    the socket tagged with the old tasks priority.

    To fix this add a check in the scm recvmsg path to update the
    sock cgrp prioidx with the new tasks value.

Let's apply the same fix for net_cls.

Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Reported-by: Li Zefan <lizefan@huawei.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: John Fastabend <john.r.fastabend@intel.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: netdev@vger.kernel.org
Cc: cgroups@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-22 14:17:38 -05:00
Eric W. Biederman
00f70de09c net: Allow userns root to force the scm creds
If the user calling sendmsg has the appropriate privieleges
in their user namespace allow them to set the uid, gid, and
pid in the SCM_CREDENTIALS control message to any valid value.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-18 20:32:45 -05:00
Linus Torvalds
aab174f0df Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
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()
  ...
2012-10-02 20:25:04 -07:00
Al Viro
cb0942b812 make get_file() return its argument
simplifies a bunch of callers...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26 21:10:25 -04:00
Eric W. Biederman
dbe9a4173e scm: Don't use struct ucred in NETLINK_CB and struct scm_cookie.
Passing uids and gids on NETLINK_CB from a process in one user
namespace to a process in another user namespace can result in the
wrong uid or gid being presented to userspace.  Avoid that problem by
passing kuids and kgids instead.

- define struct scm_creds for use in scm_cookie and netlink_skb_parms
  that holds uid and gid information in kuid_t and kgid_t.

- Modify scm_set_cred to fill out scm_creds by heand instead of using
  cred_to_ucred to fill out struct ucred.  This conversion ensures
  userspace does not get incorrect uid or gid values to look at.

- Modify scm_recv to convert from struct scm_creds to struct ucred
  before copying credential values to userspace.

- Modify __scm_send to populate struct scm_creds on in the scm_cookie,
  instead of just copying struct ucred from userspace.

- Modify netlink_sendmsg to copy scm_creds instead of struct ucred
  into the NETLINK_CB.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-07 14:42:05 -04:00
David S. Miller
e6acb38480 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
This is an initial merge in of Eric Biederman's work to start adding
user namespace support to the networking.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-24 18:54:37 -04:00
John Fastabend
48a87cc26c net: netprio: fd passed in SCM_RIGHTS datagram not set correctly
A socket fd passed in a SCM_RIGHTS datagram was not getting
updated with the new tasks cgrp prioidx. This leaves IO on
the socket tagged with the old tasks priority.

To fix this add a check in the scm recvmsg path to update the
sock cgrp prioidx with the new tasks value.

Thanks to Al Viro for catching this.

CC: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-16 14:56:11 -07:00
Eric W. Biederman
b2e4f544fd userns: Convert net/core/scm.c to use kuids and kgids
With the existence of kuid_t and kgid_t we can take this further
and remove the usage of struct cred altogether, ensuring we
don't get cache line misses from reference counts.   For now
however start simply and do a straight forward conversion
I can be certain is correct.

In cred_to_ucred use from_kuid_munged and from_kgid_munged
as these values are going directly to userspace and we want to use
the userspace safe values not -1 when reporting a value that does not
map.  The earlier conversion that used from_kuid was buggy in that
respect.  Oops.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-08-14 21:41:58 -07:00
Al Viro
6120d3dbb1 get rid of ->scm_work_list
recursion in __scm_destroy() will be cut by delaying final fput()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22 23:58:00 +04:00
David Howells
9ffc93f203 Remove all #inclusions of asm/system.h
Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`

Signed-off-by: David Howells <dhowells@redhat.com>
2012-03-28 18:30:03 +01:00
Eric Dumazet
16e5726269 af_unix: dont send SCM_CREDENTIALS by default
Since commit 7361c36c52 (af_unix: Allow credentials to work across
user and pid namespaces) af_unix performance dropped a lot.

This is because we now take a reference on pid and cred in each write(),
and release them in read(), usually done from another process,
eventually from another cpu. This triggers false sharing.

# Events: 154K cycles
#
# Overhead  Command       Shared Object        Symbol
# ........  .......  ..................  .........................
#
    10.40%  hackbench  [kernel.kallsyms]   [k] put_pid
     8.60%  hackbench  [kernel.kallsyms]   [k] unix_stream_recvmsg
     7.87%  hackbench  [kernel.kallsyms]   [k] unix_stream_sendmsg
     6.11%  hackbench  [kernel.kallsyms]   [k] do_raw_spin_lock
     4.95%  hackbench  [kernel.kallsyms]   [k] unix_scm_to_skb
     4.87%  hackbench  [kernel.kallsyms]   [k] pid_nr_ns
     4.34%  hackbench  [kernel.kallsyms]   [k] cred_to_ucred
     2.39%  hackbench  [kernel.kallsyms]   [k] unix_destruct_scm
     2.24%  hackbench  [kernel.kallsyms]   [k] sub_preempt_count
     1.75%  hackbench  [kernel.kallsyms]   [k] fget_light
     1.51%  hackbench  [kernel.kallsyms]   [k]
__mutex_lock_interruptible_slowpath
     1.42%  hackbench  [kernel.kallsyms]   [k] sock_alloc_send_pskb

This patch includes SCM_CREDENTIALS information in a af_unix message/skb
only if requested by the sender, [man 7 unix for details how to include
ancillary data using sendmsg() system call]

Note: This might break buggy applications that expected SCM_CREDENTIAL
from an unaware write() system call, and receiver not using SO_PASSCRED
socket option.

If SOCK_PASSCRED is set on source or destination socket, we still
include credentials for mere write() syscalls.

Performance boost in hackbench : more than 50% gain on a 16 thread
machine (2 quad-core cpus, 2 threads per core)

hackbench 20 thread 2000

4.228 sec instead of 9.102 sec

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-28 13:29:50 -04:00
Tim Chen
e33f7a9f37 scm: Capture the full credentials of the scm sender
This patch corrects an erroneous update of credential's gid with uid
introduced in commit 257b5358b3 since 2.6.36.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-11 05:52:57 -07:00
Al Viro
326be7b484 Allow passing O_PATH descriptors via SCM_RIGHTS datagrams
Just need to make sure that AF_UNIX garbage collector won't
confuse O_PATHed socket on filesystem for real AF_UNIX opened
socket.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 02:21:45 -04:00
Eric Dumazet
bba14de987 scm: lower SCM_MAX_FD
Lower SCM_MAX_FD from 255 to 253 so that allocations for scm_fp_list are
halved. (commit f8d570a4 added two pointers in this structure)

scm_fp_dup() should not copy whole structure (and trigger kmemcheck
warnings), but only the used part. While we are at it, only allocate
needed size.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-24 11:16:43 -08:00
Eric Dumazet
9e34a5b516 net/core: EXPORT_SYMBOL cleanups
CodingStyle cleanups

EXPORT_SYMBOL should immediately follow the symbol declaration.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-12 12:57:55 -07:00
Eric W. Biederman
257b5358b3 scm: Capture the full credentials of the scm sender.
Start capturing not only the userspace pid, uid and gid values of the
sending process but also the struct pid and struct cred of the sending
process as well.

This is in preparation for properly supporting SCM_CREDENTIALS for
sockets that have different uid and/or pid namespaces at the different
ends.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-16 14:55:56 -07:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Eric W. Biederman
76dadd76c2 scm: Only support SCM_RIGHTS on unix domain sockets.
We use scm_send and scm_recv on both unix domain and
netlink sockets, but only unix domain sockets support
everything required for file descriptor passing,
so error if someone attempts to pass file descriptors
over netlink sockets.

Cc: stable@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-28 18:22:02 -08:00
James Morris
f3a5c54701 Merge branch 'master' into next
Conflicts:
	fs/cifs/misc.c

Merge to resolve above, per the patch below.

Signed-off-by: James Morris <jmorris@namei.org>

diff --cc fs/cifs/misc.c
index ec36410,addd1dc..0000000
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@@ -347,13 -338,13 +338,13 @@@ header_assemble(struct smb_hdr *buffer
  		/*  BB Add support for establishing new tCon and SMB Session  */
  		/*      with userid/password pairs found on the smb session   */
  		/*	for other target tcp/ip addresses 		BB    */
 -				if (current->fsuid != treeCon->ses->linux_uid) {
 +				if (current_fsuid() != treeCon->ses->linux_uid) {
  					cFYI(1, ("Multiuser mode and UID "
  						 "did not match tcon uid"));
- 					read_lock(&GlobalSMBSeslock);
- 					list_for_each(temp_item, &GlobalSMBSessionList) {
- 						ses = list_entry(temp_item, struct cifsSesInfo, cifsSessionList);
+ 					read_lock(&cifs_tcp_ses_lock);
+ 					list_for_each(temp_item, &treeCon->ses->server->smb_ses_list) {
+ 						ses = list_entry(temp_item, struct cifsSesInfo, smb_ses_list);
 -						if (ses->linux_uid == current->fsuid) {
 +						if (ses->linux_uid == current_fsuid()) {
  							if (ses->server == treeCon->ses->server) {
  								cFYI(1, ("found matching uid substitute right smb_uid"));
  								buffer->Uid = ses->Suid;
2008-11-18 18:52:37 +11:00
Pavel Emelyanov
5421ae0153 scm: fix scm_fp_list->list initialization made in wrong place
This is the next page of the scm recursion story (the commit 
f8d570a4 net: Fix recursive descent in __scm_destroy()).

In function scm_fp_dup(), the INIT_LIST_HEAD(&fpl->list) of newly
created fpl is done *before* the subsequent memcpy from the old 
structure and thus the freshly initialized list is overwritten.

But that's OK, since this initialization is not required at all,
since the fpl->list is list_add-ed at the destruction time in any
case (and is unused in other code), so I propose to drop both
initializations, rather than moving it after the memcpy.

Please, correct me if I miss something significant.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-14 14:51:45 -08:00
James Morris
2b82892565 Merge branch 'master' into next
Conflicts:
	security/keys/internal.h
	security/keys/process_keys.c
	security/keys/request_key.c

Fixed conflicts above by using the non 'tsk' versions.

Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 11:29:12 +11:00
David Howells
86a264abe5 CRED: Wrap current->cred and a few other accessors
Wrap current->cred and a few other accessors to hide their actual
implementation.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:18 +11:00
David Howells
b6dff3ec5e CRED: Separate task security context from task_struct
Separate the task security context from task_struct.  At this point, the
security data is temporarily embedded in the task_struct with two pointers
pointing to it.

Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in
entry.S via asm-offsets.

With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com>

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:16 +11:00
David Howells
8192b0c482 CRED: Wrap task credential accesses in the networking subsystem
Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: netdev@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:10 +11:00
David Miller
f8d570a474 net: Fix recursive descent in __scm_destroy().
__scm_destroy() walks the list of file descriptors in the scm_fp_list
pointed to by the scm_cookie argument.

Those, in turn, can close sockets and invoke __scm_destroy() again.

There is nothing which limits how deeply this can occur.

The idea for how to fix this is from Linus.  Basically, we do all of
the fput()s at the top level by collecting all of the scm_fp_list
objects hit by an fput().  Inside of the initial __scm_destroy() we
keep running the list until it is empty.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-06 13:51:50 -08:00
Wei Yongjun
1ac70e7ad2 [NET]: Fix function put_cmsg() which may cause usr application memory overflow
When used function put_cmsg() to copy kernel information to user 
application memory, if the memory length given by user application is 
not enough, by the bad length calculate of msg.msg_controllen, 
put_cmsg() function may cause the msg.msg_controllen to be a large 
value, such as 0xFFFFFFF0, so the following put_cmsg() can also write 
data to usr application memory even usr has no valid memory to store 
this. This may cause usr application memory overflow.

int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data)
{
    struct cmsghdr __user *cm
        = (__force struct cmsghdr __user *)msg->msg_control;
    struct cmsghdr cmhdr;
    int cmlen = CMSG_LEN(len);
    ~~~~~~~~~~~~~~~~~~~~~
    int err;

    if (MSG_CMSG_COMPAT & msg->msg_flags)
        return put_cmsg_compat(msg, level, type, len, data);

    if (cm==NULL || msg->msg_controllen < sizeof(*cm)) {
        msg->msg_flags |= MSG_CTRUNC;
        return 0; /* XXX: return error? check spec. */
    }
    if (msg->msg_controllen < cmlen) {
    ~~~~~~~~~~~~~~~~~~~~~~~~
        msg->msg_flags |= MSG_CTRUNC;
        cmlen = msg->msg_controllen;
    }
    cmhdr.cmsg_level = level;
    cmhdr.cmsg_type = type;
    cmhdr.cmsg_len = cmlen;

    err = -EFAULT;
    if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
        goto out;
    if (copy_to_user(CMSG_DATA(cm), data, cmlen - sizeof(struct cmsghdr)))
        goto out;
    cmlen = CMSG_SPACE(len);
~~~~~~~~~~~~~~~~~~~~~~~~~~~
    If MSG_CTRUNC flags is set, msg->msg_controllen is less than 
CMSG_SPACE(len), "msg->msg_controllen -= cmlen" will cause unsinged int 
type msg->msg_controllen to be a large value.
~~~~~~~~~~~~~~~~~~~~~~~~~~~
    msg->msg_control += cmlen;
    msg->msg_controllen -= cmlen;
    ~~~~~~~~~~~~~~~~~~~~~
    err = 0;
out:
    return err;
}

The same promble exists in put_cmsg_compat(). This patch can fix this 
problem.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-12-20 14:36:44 -08:00
Pavel Emelyanov
b488893a39 pid namespaces: changes to show virtual ids to user
This is the largest patch in the set. Make all (I hope) the places where
the pid is shown to or get from user operate on the virtual pids.

The idea is:
 - all in-kernel data structures must store either struct pid itself
   or the pid's global nr, obtained with pid_nr() call;
 - when seeking the task from kernel code with the stored id one
   should use find_task_by_pid() call that works with global pids;
 - when showing pid's numerical value to the user the virtual one
   should be used, but however when one shows task's pid outside this
   task's namespace the global one is to be used;
 - when getting the pid from userspace one need to consider this as
   the virtual one and use appropriate task/pid-searching functions.

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: nuther build fix]
[akpm@linux-foundation.org: yet nuther build fix]
[akpm@linux-foundation.org: remove unneeded casts]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Paul Menage <menage@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:40 -07:00
Stephen Hemminger
cfcabdcc2d [NET]: sparse warning fixes
Fix a bunch of sparse warnings. Mostly about 0 used as
NULL pointer, and shadowed variable declarations.
One notable case was that hash size should have been unsigned.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:54:48 -07:00
Ulrich Drepper
4a19542e5f O_CLOEXEC for SCM_RIGHTS
Part two in the O_CLOEXEC saga: adding support for file descriptors received
through Unix domain sockets.

The patch is once again pretty minimal, it introduces a new flag for recvmsg
and passes it just like the existing MSG_CMSG_COMPAT flag.  I think this bit
is not used otherwise but the networking people will know better.

This new flag is not recognized by recvfrom and recv.  These functions cannot
be used for that purpose and the asymmetry this introduces is not worse than
the already existing MSG_CMSG_COMPAT situations.

The patch must be applied on the patch which introduced O_CLOEXEC.  It has to
remove static from the new get_unused_fd_flags function but since scm.c cannot
live in a module the function still hasn't to be exported.

Here's a test program to make sure the code works.  It's so much longer than
the actual patch...

#include <errno.h>
#include <error.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/un.h>

#ifndef O_CLOEXEC
# define O_CLOEXEC 02000000
#endif
#ifndef MSG_CMSG_CLOEXEC
# define MSG_CMSG_CLOEXEC 0x40000000
#endif

int
main (int argc, char *argv[])
{
  if (argc > 1)
    {
      int fd = atol (argv[1]);
      printf ("child: fd = %d\n", fd);
      if (fcntl (fd, F_GETFD) == 0 || errno != EBADF)
        {
          puts ("file descriptor valid in child");
          return 1;
        }
      return 0;

    }

  struct sockaddr_un sun;
  strcpy (sun.sun_path, "./testsocket");
  sun.sun_family = AF_UNIX;

  char databuf[] = "hello";
  struct iovec iov[1];
  iov[0].iov_base = databuf;
  iov[0].iov_len = sizeof (databuf);

  union
  {
    struct cmsghdr hdr;
    char bytes[CMSG_SPACE (sizeof (int))];
  } buf;
  struct msghdr msg = { .msg_iov = iov, .msg_iovlen = 1,
                        .msg_control = buf.bytes,
                        .msg_controllen = sizeof (buf) };
  struct cmsghdr *cmsg = CMSG_FIRSTHDR (&msg);

  cmsg->cmsg_level = SOL_SOCKET;
  cmsg->cmsg_type = SCM_RIGHTS;
  cmsg->cmsg_len = CMSG_LEN (sizeof (int));

  msg.msg_controllen = cmsg->cmsg_len;

  pid_t child = fork ();
  if (child == -1)
    error (1, errno, "fork");
  if (child == 0)
    {
      int sock = socket (PF_UNIX, SOCK_STREAM, 0);
      if (sock < 0)
        error (1, errno, "socket");

      if (bind (sock, (struct sockaddr *) &sun, sizeof (sun)) < 0)
        error (1, errno, "bind");
      if (listen (sock, SOMAXCONN) < 0)
        error (1, errno, "listen");

      int conn = accept (sock, NULL, NULL);
      if (conn == -1)
        error (1, errno, "accept");

      *(int *) CMSG_DATA (cmsg) = sock;
      if (sendmsg (conn, &msg, MSG_NOSIGNAL) < 0)
        error (1, errno, "sendmsg");

      return 0;
    }

  /* For a test suite this should be more robust like a
     barrier in shared memory.  */
  sleep (1);

  int sock = socket (PF_UNIX, SOCK_STREAM, 0);
  if (sock < 0)
    error (1, errno, "socket");

  if (connect (sock, (struct sockaddr *) &sun, sizeof (sun)) < 0)
    error (1, errno, "connect");
  unlink (sun.sun_path);

  *(int *) CMSG_DATA (cmsg) = -1;

  if (recvmsg (sock, &msg, MSG_CMSG_CLOEXEC) < 0)
    error (1, errno, "recvmsg");

  int fd = *(int *) CMSG_DATA (cmsg);
  if (fd == -1)
    error (1, 0, "no descriptor received");

  char fdname[20];
  snprintf (fdname, sizeof (fdname), "%d", fd);
  execl ("/proc/self/exe", argv[0], fdname, NULL);
  puts ("execl failed");
  return 1;
}

[akpm@linux-foundation.org: Fix fastcall inconsistency noted by Michael Buesch]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:45 -07:00
YOSHIFUJI Hideaki
4ec93edb14 [NET] CORE: Fix whitespace errors.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-10 23:19:25 -08:00
Miklos Szeredi
effee6a000 [NET]: File descriptor loss while receiving SCM_RIGHTS
If more than one file descriptor was sent with an SCM_RIGHTS message,
and on the receiving end, after installing a nonzero (but not all)
file descritpors the process runs out of fds, then the already
installed fds will be lost (userspace will have no way of knowing
about them).

The following patch makes sure, that at least the already installed
fds are sent to userspace.  It doesn't solve the issue of losing file
descriptors in case of an EFAULT on the userspace buffer.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-10-11 23:59:48 -07:00
Randy Dunlap
4fc268d24c [PATCH] capable/capability.h (net/)
net: Use <linux/capability.h> where capable() is used.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11 18:42:14 -08:00
Al Viro
b453257f05 [PATCH] kill gratitious includes of major.h under net/*
A lot of places in there are including major.h for no reason whatsoever.
Removed.  And yes, it still builds. 

The history of that stuff is often amusing.  E.g.  for net/core/sock.c
the story looks so, as far as I've been able to reconstruct it: we used
to need major.h in net/socket.c circa 1.1.early.  In 1.1.13 that need
had disappeared, along with register_chrdev(SOCKET_MAJOR, "socket",
&net_fops) in sock_init().  Include had not.  When 1.2 -> 1.3 reorg of
net/* had moved a lot of stuff from net/socket.c to net/core/sock.c,
this crap had followed... 

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-25 18:32:13 -07:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00