UBUNTU: Ubuntu-2.6.32-45.103

Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
UBUNTU: Start new release

Ignore: yes
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
ptrace: ptrace_resume() shouldn't wake up !TASK_TRACED thread

CVE-2013-0871

BugLink: http://bugs.launchpad.net/bugs/1129192

It is not clear why ptrace_resume() does wake_up_process(). Unless the
caller is PTRACE_KILL the tracee should be TASK_TRACED so we can use
wake_up_state(__TASK_TRACED). If sys_ptrace() races with SIGKILL we do
not need the extra and potentionally spurious wakeup.

If the caller is PTRACE_KILL, wake_up_process() is even more wrong.
The tracee can sleep in any state in any place, and if we have a buggy
code which doesn't handle a spurious wakeup correctly PTRACE_KILL can
be used to exploit it. For example:

	int main(void)
	{
		int child, status;

		child = fork();
		if (!child) {
			int ret;

			assert(ptrace(PTRACE_TRACEME, 0,0,0) == 0);

			ret = pause();
			printf("pause: %d %m\n", ret);

			return 0x23;
		}

		sleep(1);
		assert(ptrace(PTRACE_KILL, child, 0,0) == 0);

		assert(child == wait(&status));
		printf("wait: %x\n", status);

		return 0;
	}

prints "pause: -1 Unknown error 514", -ERESTARTNOHAND leaks to the
userland. In this case sys_pause() is buggy as well and should be
fixed.

I do not know what was the original rationality behind PTRACE_KILL.
The man page is simply wrong and afaics it was always wrong. Imho
it should be deprecated, or may be it should do send_sig(SIGKILL)
as Denys suggests, but in any case I do not think that the current
behaviour was intentional.

Note: there is another problem, ptrace_resume() changes ->exit_code
and this can race with SIGKILL too. Eventually we should change ptrace
to not use ->exit_code.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
(cherry picked from commit 0666fb51b1483f27506e212cc7f7b2645b5c7acc)

Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Acked-by: Colin King <colin.king@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
ptrace: introduce signal_wake_up_state() and ptrace_signal_wake_up()

CVE-2013-0871

BugLink: http://bugs.launchpad.net/bugs/1129192

Cleanup and preparation for the next change.

signal_wake_up(resume => true) is overused. None of ptrace/jctl callers
actually want to wakeup a TASK_WAKEKILL task, but they can't specify the
necessary mask.

Turn signal_wake_up() into signal_wake_up_state(state), reintroduce
signal_wake_up() as a trivial helper, and add ptrace_signal_wake_up()
which adds __TASK_TRACED.

This way ptrace_signal_wake_up() can work "inside" ptrace_request()
even if the tracee doesn't have the TASK_WAKEKILL bit set.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(backported from commit 910ffdb18a6408e14febbb6e4b6840fd2c928c82)

Conflicts:
	kernel/ptrace.c
	kernel/signal.c

Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Acked-by: Colin King <colin.king@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
ptrace: ensure arch_ptrace/ptrace_request can never race with SIGKILL

CVE-2013-0871

BugLink: http://bugs.launchpad.net/bugs/1129192

putreg() assumes that the tracee is not running and pt_regs_access() can
safely play with its stack.  However a killed tracee can return from
ptrace_stop() to the low-level asm code and do RESTORE_REST, this means
that debugger can actually read/modify the kernel stack until the tracee
does SAVE_REST again.

set_task_blockstep() can race with SIGKILL too and in some sense this
race is even worse, the very fact the tracee can be woken up breaks the
logic.

As Linus suggested we can clear TASK_WAKEKILL around the arch_ptrace()
call, this ensures that nobody can ever wakeup the tracee while the
debugger looks at it.  Not only this fixes the mentioned problems, we
can do some cleanups/simplifications in arch_ptrace() paths.

Probably ptrace_unfreeze_traced() needs more callers, for example it
makes sense to make the tracee killable for oom-killer before
access_process_vm().

While at it, add the comment into may_ptrace_stop() to explain why
ptrace_stop() still can't rely on SIGKILL and signal_pending_state().

Reported-by: Salman Qazi <sqazi@google.com>
Reported-by: Suleiman Souhlal <suleiman@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(backported from commit 9899d11f654474d2d54ea52ceaa2a1f4db3abd68)

Conflicts:
	arch/x86/kernel/step.c
	kernel/ptrace.c
	kernel/signal.c

Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Acked-by: Colin King <colin.king@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
wake_up_process() should be never used to wakeup a TASK_STOPPED/TRACED task

CVE-2013-0871

BugLink: http://bugs.launchpad.net/bugs/1129192

wake_up_process() should never wakeup a TASK_STOPPED/TRACED task.
Change it to use TASK_NORMAL and add the WARN_ON().

TASK_ALL has no other users, probably can be killed.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(backported from commit 9067ac85d533651b98c2ff903182a20cbb361fcb)

Conflicts:
	kernel/sched/core.c

Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Acked-by: Colin King <colin.king@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
UBUNTU: Ubuntu-2.6.32-45.104

Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
UBUNTU: Start new release

Ignore: yes
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
x86/msr: Add capabilities check

CVE-2013-0268

BugLink: http://bugs.launchpad.net/bugs/1123049

At the moment the MSR driver only relies upon file system
checks. This means that anything as root with any capability set
can write to MSRs. Historically that wasn't very interesting but
on modern processors the MSRs are such that writing to them
provides several ways to execute arbitary code in kernel space.
Sample code and documentation on doing this is circulating and
MSR attacks are used on Windows 64bit rootkits already.

In the Linux case you still need to be able to open the device
file so the impact is fairly limited and reduces the security of
some capability and security model based systems down towards
that of a generic "root owns the box" setup.

Therefore they should require CAP_SYS_RAWIO to prevent an
elevation of capabilities. The impact of this is fairly minimal
on most setups because they don't have heavy use of
capabilities. Those using SELinux, SMACK or AppArmor rules might
want to consider if their rulesets on the MSR driver could be
tighter.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Horses <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
(back ported from commit c903f0456bc69176912dee6dd25c6a66ee1aed00)

Conflicts:
	arch/x86/kernel/msr.c

Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Acked-by: Leann Ogasawara <leann.ogasawara@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
mm: thp: fix pmd_present for split_huge_page and PROT_NONE with THP

CVE-2013-0309

BugLink: http://bugs.launchpad.net/bugs/1130943

In many places !pmd_present has been converted to pmd_none.  For pmds
that's equivalent and pmd_none is quicker so using pmd_none is better.

However (unless we delete pmd_present) we should provide an accurate
pmd_present too.  This will avoid the risk of code thinking the pmd is non
present because it's under __split_huge_page_map, see the pmd_mknotpresent
there and the comment above it.

If the page has been mprotected as PROT_NONE, it would also lead to a
pmd_present false negative in the same way as the race with
split_huge_page.

Because the PSE bit stays on at all times (both during split_huge_page and
when the _PAGE_PROTNONE bit get set), we could only check for the PSE bit,
but checking the PROTNONE bit too is still good to remember pmd_present
must always keep PROT_NONE into account.

This explains a not reproducible BUG_ON that was seldom reported on the
lists.

The same issue is in pmd_large, it would go wrong with both PROT_NONE and
if it races with split_huge_page.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 027ef6c87853b0a9df53175063028edb4950d476)

Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
UBUNTU: Bump ABI

Ignore: yes
Signed-off-by: Brad Figg <brad.figg@canonical.com>
NLS: improve UTF8 -> UTF16 string conversion routine

CVE-2013-1773

BugLink: https://launchpad.net/bugs/1134523

The utf8s_to_utf16s conversion routine needs to be improved.  Unlike
its utf16s_to_utf8s sibling, it doesn't accept arguments specifying
the maximum length of the output buffer or the endianness of its
16-bit output.

This patch (as1501) adds the two missing arguments, and adjusts the
only two places in the kernel where the function is called.  A
follow-on patch will add a third caller that does utilize the new
capabilities.

The two conversion routines are still annoyingly inconsistent in the
way they handle invalid byte combinations.  But that's a subject for a
different patch.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

(backported from commit 0720a06a7518c9d0c0125bd5d1f3b6264c55c3dd)
Conflicts:
    drivers/hv/hv_kvp.c
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Steve Conklin <steve.conklin@canonical.com>
UBUNTU: Ubuntu-2.6.32-46.105

Signed-off-by: Brad Figg <brad.figg@canonical.com>
UBUNTU: Start new release

Ignore: yes
Signed-off-by: Brad Figg <brad.figg@canonical.com>