mm: add a field to store names for private anonymous memory

Userspace processes often have multiple allocators that each do
anonymous mmaps to get memory.  When examining memory usage of
individual processes or systems as a whole, it is useful to be
able to break down the various heaps that were allocated by
each layer and examine their size, RSS, and physical memory
usage.

This patch adds a user pointer to the shared union in
vm_area_struct that points to a null terminated string inside
the user process containing a name for the vma.  vmas that
point to the same address will be merged, but vmas that
point to equivalent strings at different addresses will
not be merged.

Userspace can set the name for a region of memory by calling
prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, start, len, (unsigned long)name);
Setting the name to NULL clears it.

The names of named anonymous vmas are shown in /proc/pid/maps
as [anon:<name>] and in /proc/pid/smaps in a new "Name" field
that is only present for named vmas.  If the userspace pointer
is no longer valid all or part of the name will be replaced
with "<fault>".

The idea to store a userspace pointer to reduce the complexity
within mm (at the expense of the complexity of reading
/proc/pid/mem) came from Dave Hansen.  This results in no
runtime overhead in the mm subsystem other than comparing
the anon_name pointers when considering vma merging.  The pointer
is stored in a union with fieds that are only used on file-backed
mappings, so it does not increase memory usage.

Change-Id: Ie2ffc0967d4ffe7ee4c70781313c7b00cf7e3092
Signed-off-by: Colin Cross <ccross@android.com>

Conflicts:
	include/linux/prctl.h
	kernel/sys.c
Change-Id: Ie8bdf7850d576b895017de06ca67ec224ef8daf8
Signed-off-by: Michael Vines <mvines@codeaurora.org>
Merge "mm: add a field to store names for private anonymous memory"
net: ipv4: current group_info should be put after using.

Plug a group_info refcount leak in ping_init.
group_info is only needed during initialization and
the code failed to release the reference on exit.
While here move grabbing the reference to a place
where it is actually needed.

Change-Id: I38d476f49e7ae300bc1168bc4b2c1b67274a51ca
Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Zhang Dongxing <dongxing.zhang@intel.com>
Signed-off-by: xiaoming wang <xiaoming.wang@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Git-commit:b04c46190219a4f845e46a459e3102137b7f6cac
Git-repo: https://git.kernel.org/cgit/linux/kernel/git/davem/net.git
Signed-off-by: Divya Sharma <c_shard@codeaurora.org>
[rsiddoji@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Ravi Kumar S <rsiddoji@codeaurora.org>
net: ipv4: current group_info should be put after using.

Plug a group_info refcount leak in ping_init.
group_info is only needed during initialization and
the code failed to release the reference on exit.
While here move grabbing the reference to a place
where it is actually needed.

Change-Id: I38d476f49e7ae300bc1168bc4b2c1b67274a51ca
Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Zhang Dongxing <dongxing.zhang@intel.com>
Signed-off-by: xiaoming wang <xiaoming.wang@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Git-commit:b04c46190219a4f845e46a459e3102137b7f6cac
Git-repo: https://git.kernel.org/cgit/linux/kernel/git/davem/net.git
Signed-off-by: Divya Sharma <c_shard@codeaurora.org>
[rsiddoji@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Ravi Kumar S <rsiddoji@codeaurora.org>
n_tty: Fix n_tty_write crash when echoing in raw mode

The tty atomic_write_lock does not provide an exclusion guarantee for
the tty driver if the termios settings are LECHO & !OPOST. And since
it is unexpected and not allowed to call TTY buffer helpers like
tty_insert_flip_string concurrently, this may lead to crashes when
concurrect writers call pty_write. In that case the following two
writers:
* the ECHOing from a workqueue and
* pty_write from the process
race and can overflow the corresponding TTY buffer like follows.

If we look into tty_insert_flip_string_fixed_flag, there is:
  int space = __tty_buffer_request_room(port, goal, flags);
  struct tty_buffer *tb = port->buf.tail;
  ...
  memcpy(char_buf_ptr(tb, tb->used), chars, space);
  ...
  tb->used += space;

so the race of the two can result in something like this:
          A                             B
   __tty_buffer_request_room
                                  __tty_buffer_request_room
   memcpy(buf(tb->used), ...)
   tb->used += space;
                                 memcpy(buf(tb->used), ...) ->BOOM

B's memcpy is past the tty_buffer due to the previous A's tb->used
increment.

Since the N_TTY line discipline input processing can output
concurrently with a tty write, obtain the N_TTY ldisc output_lock to
serialize echo output with normal tty writes. This ensures the tty
buffer helper tty_insert_flip_string is not called concurrently and
everything is fine.

Note that this is nicely reproducible by an ordinary user using
forkpty and some setup around that (raw termios + ECHO). And it is
present in kernels at least after commit
d945cb9cce20ac7143c2de8d88b187f62db99bdc (pty: Rework the pty layer to
use the normal buffering logic) in 2.6.31-rc3.

js: add more info to the commit log
js: switch to bool
js: lock unconditionally
js: lock only the tty->ops->write call

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: I9e235db6ec2bb950f26bd8a23f6145dab5dc0a15
Git-commit: 4291086b1f081b869c6d79e5b7441633dc3ace00
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Avijit Kanti Das <avijitnsec@codeaurora.org>
[rsiddoji@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Ravi Kumar S <rsiddoji@codeaurora.org>
n_tty: Fix n_tty_write crash when echoing in raw mode

The tty atomic_write_lock does not provide an exclusion guarantee for
the tty driver if the termios settings are LECHO & !OPOST. And since
it is unexpected and not allowed to call TTY buffer helpers like
tty_insert_flip_string concurrently, this may lead to crashes when
concurrect writers call pty_write. In that case the following two
writers:
* the ECHOing from a workqueue and
* pty_write from the process
race and can overflow the corresponding TTY buffer like follows.

If we look into tty_insert_flip_string_fixed_flag, there is:
  int space = __tty_buffer_request_room(port, goal, flags);
  struct tty_buffer *tb = port->buf.tail;
  ...
  memcpy(char_buf_ptr(tb, tb->used), chars, space);
  ...
  tb->used += space;

so the race of the two can result in something like this:
          A                             B
   __tty_buffer_request_room
                                  __tty_buffer_request_room
   memcpy(buf(tb->used), ...)
   tb->used += space;
                                 memcpy(buf(tb->used), ...) ->BOOM

B's memcpy is past the tty_buffer due to the previous A's tb->used
increment.

Since the N_TTY line discipline input processing can output
concurrently with a tty write, obtain the N_TTY ldisc output_lock to
serialize echo output with normal tty writes. This ensures the tty
buffer helper tty_insert_flip_string is not called concurrently and
everything is fine.

Note that this is nicely reproducible by an ordinary user using
forkpty and some setup around that (raw termios + ECHO). And it is
present in kernels at least after commit
d945cb9cce20ac7143c2de8d88b187f62db99bdc (pty: Rework the pty layer to
use the normal buffering logic) in 2.6.31-rc3.

js: add more info to the commit log
js: switch to bool
js: lock unconditionally
js: lock only the tty->ops->write call

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: I9e235db6ec2bb950f26bd8a23f6145dab5dc0a15
Git-commit: 4291086b1f081b869c6d79e5b7441633dc3ace00
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Avijit Kanti Das <avijitnsec@codeaurora.org>
[rsiddoji@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Ravi Kumar S <rsiddoji@codeaurora.org>
Merge "net: ipv4: current group_info should be put after using."
Merge "n_tty: Fix n_tty_write crash when echoing in raw mode"
Merge "net: ipv4: current group_info should be put after using."
Merge "n_tty: Fix n_tty_write crash when echoing in raw mode"
Update to AU_LINUX_ANDROID_LNX.LA.3.5.2.1.04.04.02.060.117

Change-Id: I35a33ba1e2d601171ab1667be2199f075f20afdb
Signed-off-by: B2G User <b2guser@localhost>
Merge "Update to AU_LINUX_ANDROID_LNX.LA.3.5.2.1.04.04.02.060.117"
seq_file: introduce seq_setwidth() and seq_pad()

There are several users who want to know bytes written by seq_*() for
alignment purpose.  Currently they are using %n format for knowing it
because seq_*() returns 0 on success.

This patch introduces seq_setwidth() and seq_pad() for allowing them to
align without using %n format.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: 839cc2a94cc3665bafe32203c2f095f4dd470a80)
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
CRs-fixed: 665291
Change-Id: I727d9af5ed320d717295c9d0f82c88623fb181c1
Signed-off-by: David Brown <davidb@codeaurora.org>
vsprintf: ignore %n again

This ignores %n in printf again, as was originally documented.
Implementing %n poses a greater security risk than utility, so it should
stay ignored.  To help anyone attempting to use %n, a warning will be
emitted if it is encountered.

Based on an earlier patch by Joe Perches.

Because %n was designed to write to pointers on the stack, it has been
frequently used as an attack vector when bugs are found that leak
user-controlled strings into functions that ultimately process format
strings.  While this class of bug can still be turned into an
information leak, removing %n eliminates the common method of elevating
such a bug into an arbitrary kernel memory writing primitive,
significantly reducing the danger of this class of bug.

For seq_file users that need to know the length of a written string for
padding, please see seq_setwidth() and seq_pad() instead.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: 9196436ab2f713b823a2ba2024cb69f40b2f54a5
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
CRs-fixed: 665291
Change-Id: Id191acaf66e3c395df92b0a77331269b525e3cad
Signed-off-by: David Brown <davidb@codeaurora.org>
Merge "vsprintf: ignore %n again"
Merge "seq_file: introduce seq_setwidth() and seq_pad()"
futex-prevent-requeue-pi-on-same-futex.patch futex: Forbid uaddr == uaddr2 in futex_requeue(..., requeue_pi=1)

If uaddr == uaddr2, then we have broken the rule of only requeueing from
a non-pi futex to a pi futex with this call.  If we attempt this, then
dangling pointers may be left for rt_waiter resulting in an exploitable
condition.

This change brings futex_requeue() in line with futex_wait_requeue_pi()
which performs the same check as per commit 6f7b0a2a5c0f ("futex: Forbid
uaddr == uaddr2 in futex_wait_requeue_pi()")

[ tglx: Compare the resulting keys as well, as uaddrs might be
  	different depending on the mapping ]

Fixes CVE-2014-3153.

Reported-by: Pinkie Pie
Signed-off-by: Will Drewry <wad@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: I9ee5c8a87cc43c7b1e1dc2796949e7c20c74ddf4
Git-commit: e9c243a5a6de0be8e584c604d353412584b592f8
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Divya Sharma <c_shard@codeaurora.org>
Merge "futex-prevent-requeue-pi-on-same-futex.patch futex: Forbid uaddr == uaddr2 in futex_requeue(..., requeue_pi=1)"
Revert "futex-prevent-requeue-pi-on-same-futex.patch futex: Forbid uaddr == uaddr2 in futex_requeue(..., requeue_pi=1)"

This reverts commit f522bee97766cf29bcf80d1753eee0bab24963f6.

Change-Id: I0d007786e064bb752e5237245141d6fcdc287d63
Signed-off-by: Michael Vines <mvines@codeaurora.org>
Merge "Revert "futex-prevent-requeue-pi-on-same-futex.patch futex: Forbid uaddr == uaddr2 in futex_requeue(..., requeue_pi=1)""