keys: fix race with concurrent install_user_keyrings()

This fixes CVE-2013-1792.
CVE-2013-1792

BugLink: http://bugs.launchpad.net/bugs/1152788

There is a race in install_user_keyrings() that can cause a NULL pointer
dereference when called concurrently for the same user if the uid and
uid-session keyrings are not yet created.  It might be possible for an
unprivileged user to trigger this by calling keyctl() from userspace in
parallel immediately after logging in.

Assume that we have two threads both executing lookup_user_key(), both
looking for KEY_SPEC_USER_SESSION_KEYRING.

	THREAD A			THREAD B
	===============================	===============================
					==>call install_user_keyrings();
	if (!cred->user->session_keyring)
	==>call install_user_keyrings()
					...
					user->uid_keyring = uid_keyring;
	if (user->uid_keyring)
		return 0;
	<==
	key = cred->user->session_keyring [== NULL]
					user->session_keyring = session_keyring;
	atomic_inc(&key->usage); [oops]

At the point thread A dereferences cred->user->session_keyring, thread B
hasn't updated user->session_keyring yet, but thread A assumes it is
populated because install_user_keyrings() returned ok.

The race window is really small but can be exploited if, for example,
thread B is interrupted or preempted after initializing uid_keyring, but
before doing setting session_keyring.

This couldn't be reproduced on a stock kernel.  However, after placing
systemtap probe on 'user->session_keyring = session_keyring;' that
introduced some delay, the kernel could be crashed reliably.

Fix this by checking both pointers before deciding whether to return.
Alternatively, the test could be done away with entirely as it is checked
inside the mutex - but since the mutex is global, that may not be the best
way.

Signed-off-by: David Howells <dhowells@redhat.com>
Reported-by: Mateusz Guzik <mguzik@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
(cherry picked from commit 0da9dfdd2cd9889201bc6f6f43580c99165cd087)
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
ARM: VFP: fix emulation of second VFP instruction

BugLink: http://bugs.launchpad.net/bugs/1155651

commit 5e4ba617c1b584b2e376f31a63bd4e734109318a upstream.

Martin Storsjö reports that the sequence:

        ee312ac1        vsub.f32        s4, s3, s2
        ee702ac0        vsub.f32        s5, s1, s0
        e59f0028        ldr             r0, [pc, #40]
        ee111a90        vmov            r1, s3

on Raspberry Pi (implementor 41 architecture 1 part 20 variant b rev 5)
where s3 is a denormal and s2 is zero results in incorrect behaviour -
the instruction "vsub.f32 s5, s1, s0" is not executed:

        VFP: bounce: trigger ee111a90 fpexc d0000780
        VFP: emulate: INST=0xee312ac1 SCR=0x00000000
        ...

As we can see, the instruction triggering the exception is the "vmov"
instruction, and we emulate the "vsub.f32 s4, s3, s2" but fail to
properly take account of the FPEXC_FP2V flag in FPEXC.  This is because
the test for the second instruction register being valid is bogus, and
will always skip emulation of the second instruction.

Reported-by: Martin Storsjö <martin@martin.st>
Tested-by: Martin Storsjö <martin@martin.st>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
ARM: fix scheduling while atomic warning in alignment handling code

BugLink: http://bugs.launchpad.net/bugs/1155651

commit b255188f90e2bade1bd11a986dd1ca4861869f4d upstream.

Paolo Pisati reports that IPv6 triggers this warning:

BUG: scheduling while atomic: swapper/0/0/0x40000100
Modules linked in:
[<c001b1c4>] (unwind_backtrace+0x0/0xf0) from [<c0503c5c>] (__schedule_bug+0x48/0x5c)
[<c0503c5c>] (__schedule_bug+0x48/0x5c) from [<c0508608>] (__schedule+0x700/0x740)
[<c0508608>] (__schedule+0x700/0x740) from [<c007007c>] (__cond_resched+0x24/0x34)
[<c007007c>] (__cond_resched+0x24/0x34) from [<c05086dc>] (_cond_resched+0x3c/0x44)
[<c05086dc>] (_cond_resched+0x3c/0x44) from [<c0021f6c>] (do_alignment+0x178/0x78c)
[<c0021f6c>] (do_alignment+0x178/0x78c) from [<c00083e0>] (do_DataAbort+0x34/0x98)
[<c00083e0>] (do_DataAbort+0x34/0x98) from [<c0509a60>] (__dabt_svc+0x40/0x60)
Exception stack(0xc0763d70 to 0xc0763db8)
3d60:                                     e97e805e e97e806e 2c000000 11000000
3d80: ea86bb00 0000002c 00000011 e97e807e c076d2a8 e97e805e e97e806e 0000002c
3da0: 3d000000 c0763dbc c04b98fc c02a8490 00000113 ffffffff
[<c0509a60>] (__dabt_svc+0x40/0x60) from [<c02a8490>] (__csum_ipv6_magic+0x8/0xc8)

Fix this by using probe_kernel_address() stead of __get_user().

Reported-by: Paolo Pisati <p.pisati@gmail.com>
Tested-by: Paolo Pisati <p.pisati@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
SCSI: dc395x: uninitialized variable in device_alloc()

BugLink: http://bugs.launchpad.net/bugs/1155651

commit 208afec4f3be8c51ad6eebe6611dd6d2ad2fa298 upstream.

This bug was introduced back in bitkeeper days in 2003.  We use
"dcb->dev_mode" before it has been initialized.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
target/pscsi: Fix page increment

BugLink: http://bugs.launchpad.net/bugs/1155651

commit 472b72f2db7831d7dbe22ffdff4adee3bd49b05d upstream.

The page++ is wrong. It makes bio_add_pc_page() pointing to a wrong page
address if the 'while (len > 0 && data_len > 0) { ... }' loop is
executed more than one once.

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
btrfs: Init io_lock after cloning btrfs device struct

BugLink: http://bugs.launchpad.net/bugs/1155651

commit 1cba0cdf5e4dbcd9e5fa5b54d7a028e55e2ca057 upstream.

__btrfs_close_devices() clones btrfs device structs with
memcpy(). Some of the fields in the clone are reinitialized, but it's
missing to init io_lock. In mainline this goes unnoticed, but on RT it
leaves the plist pointing to the original about to be freed lock
struct.

Initialize io_lock after cloning, so no references to the original
struct are left.

Reported-and-tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
cifs: ensure that cifs_get_root() only traverses directories

BugLink: http://bugs.launchpad.net/bugs/1155651

commit ce2ac52105aa663056dfc17966ebed1bf93e6e64 upstream.

Kjell Braden reported this oops:

[  833.211970] BUG: unable to handle kernel NULL pointer dereference at           (null)
[  833.212816] IP: [<          (null)>]           (null)
[  833.213280] PGD 1b9b2067 PUD e9f7067 PMD 0
[  833.213874] Oops: 0010 [#1] SMP
[  833.214344] CPU 0
[  833.214458] Modules linked in: des_generic md4 nls_utf8 cifs vboxvideo drm snd_intel8x0 snd_ac97_codec ac97_bus snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq bnep rfcomm snd_timer bluetooth snd_seq_device ppdev snd vboxguest parport_pc joydev mac_hid soundcore snd_page_alloc psmouse i2c_piix4 serio_raw lp parport usbhid hid e1000
[  833.215629]
[  833.215629] Pid: 1752, comm: mount.cifs Not tainted 3.0.0-rc7-bisectcifs-fec11dd9a0+ #18 innotek GmbH VirtualBox/VirtualBox
[  833.215629] RIP: 0010:[<0000000000000000>]  [<          (null)>]           (null)
[  833.215629] RSP: 0018:ffff8800119c9c50  EFLAGS: 00010282
[  833.215629] RAX: ffffffffa02186c0 RBX: ffff88000c427780 RCX: 0000000000000000
[  833.215629] RDX: 0000000000000000 RSI: ffff88000c427780 RDI: ffff88000c4362e8
[  833.215629] RBP: ffff8800119c9c88 R08: ffff88001fc15e30 R09: 00000000d69515c7
[  833.215629] R10: ffffffffa0201972 R11: ffff88000e8f6a28 R12: ffff88000c4362e8
[  833.215629] R13: 0000000000000000 R14: 0000000000000000 R15: ffff88001181aaa6
[  833.215629] FS:  00007f2986171700(0000) GS:ffff88001fc00000(0000) knlGS:0000000000000000
[  833.215629] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  833.215629] CR2: 0000000000000000 CR3: 000000001b982000 CR4: 00000000000006f0
[  833.215629] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  833.215629] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  833.215629] Process mount.cifs (pid: 1752, threadinfo ffff8800119c8000, task ffff88001c1c16f0)
[  833.215629] Stack:
[  833.215629]  ffffffff8116a9b5 ffff8800119c9c88 ffffffff81178075 0000000000000286
[  833.215629]  0000000000000000 ffff88000c4276c0 ffff8800119c9ce8 ffff8800119c9cc8
[  833.215629]  ffffffff8116b06e ffff88001bc6fc00 ffff88000c4276c0 ffff88000c4276c0
[  833.215629] Call Trace:
[  833.215629]  [<ffffffff8116a9b5>] ? d_alloc_and_lookup+0x45/0x90
[  833.215629]  [<ffffffff81178075>] ? d_lookup+0x35/0x60
[  833.215629]  [<ffffffff8116b06e>] __lookup_hash.part.14+0x9e/0xc0
[  833.215629]  [<ffffffff8116b1d6>] lookup_one_len+0x146/0x1e0
[  833.215629]  [<ffffffff815e4f7e>] ? _raw_spin_lock+0xe/0x20
[  833.215629]  [<ffffffffa01eef0d>] cifs_do_mount+0x26d/0x500 [cifs]
[  833.215629]  [<ffffffff81163bd3>] mount_fs+0x43/0x1b0
[  833.215629]  [<ffffffff8117d41a>] vfs_kern_mount+0x6a/0xd0
[  833.215629]  [<ffffffff8117e584>] do_kern_mount+0x54/0x110
[  833.215629]  [<ffffffff8117fdc2>] do_mount+0x262/0x840
[  833.215629]  [<ffffffff81108a0e>] ? __get_free_pages+0xe/0x50
[  833.215629]  [<ffffffff8117f9ca>] ? copy_mount_options+0x3a/0x180
[  833.215629]  [<ffffffff8118075d>] sys_mount+0x8d/0xe0
[  833.215629]  [<ffffffff815ece82>] system_call_fastpath+0x16/0x1b
[  833.215629] Code:  Bad RIP value.
[  833.215629] RIP  [<          (null)>]           (null)
[  833.215629]  RSP <ffff8800119c9c50>
[  833.215629] CR2: 0000000000000000
[  833.238525] ---[ end trace ec00758b8d44f529 ]---

When walking down the path on the server, it's possible to hit a
symlink. The path walking code assumes that the caller will handle that
situation properly, but cifs_get_root() isn't set up for it. This patch
prevents the oops by simply returning an error.

A better solution would be to try and chase the symlinks here, but that's
fairly complicated to handle.

Fixes:

    https://bugzilla.kernel.org/show_bug.cgi?id=53221

Reported-and-tested-by: Kjell Braden <afflux@pentabarf.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
SUNRPC: Don't start the retransmission timer when out of socket space

BugLink: http://bugs.launchpad.net/bugs/1155651

commit a9a6b52ee1baa865283a91eb8d443ee91adfca56 upstream.

If the socket is full, we're better off just waiting until it empties,
or until the connection is broken. The reason why we generally don't
want to time out is that the call to xprt->ops->release_xprt() will
trigger a connection reset, which isn't helpful...

Let's make an exception for soft RPC calls, since they have to provide
timeout guarantees.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
hw_random: make buffer usable in scatterlist.

BugLink: http://bugs.launchpad.net/bugs/1155651

commit f7f154f1246ccc5a0a7e9ce50932627d60a0c878 upstream.

virtio_rng feeds the randomness buffer handed by the core directly
into the scatterlist, since commit bb347d98079a547e80bd4722dee1de61e4dca0e8.

However, if CONFIG_HW_RANDOM=m, the static buffer isn't a linear address
(at least on most archs).  We could fix this in virtio_rng, but it's actually
far easier to just do it in the core as virtio_rng would have to allocate
a buffer every time (it doesn't know how much the core will want to read).

Reported-by: Aurelien Jarno <aurelien@aurel32.net>
Tested-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
ath9k: fix RSSI dummy marker value

BugLink: http://bugs.launchpad.net/bugs/1155651

commit a3d63cadbad97671d740a9698acc2c95d1ca6e79 upstream.

RSSI is being stored internally as s8 in several places. The indication
of an unset RSSI value, ATH_RSSI_DUMMY_MARKER, was supposed to have been
set to 127, but ended up being set to 0x127 because of a code cleanup
mistake. This could lead to invalid signal strength values in a few
places.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
md: raid0: fix error return from create_stripe_zones.

BugLink: http://bugs.launchpad.net/bugs/1155651

commit 58ebb34c49fcfcaa029e4b1c1453d92583900f9a upstream.

Create_stripe_zones returns an error slightly differently to
raid0_run and to raid0_takeover_*.

The error returned used by the second was wrong and an error would
result in mddev->private being set to NULL and sooner or later a
crash.

So never return NULL, return ERR_PTR(err), not NULL from
create_stripe_zones.

This bug has been present since 2.6.35 so the fix is suitable
for any kernel since then.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
hwmon: (sht15) Check return value of regulator_enable()

BugLink: http://bugs.launchpad.net/bugs/1155651

commit 3e78080f81481aa8340374d5a37ae033c1cf4272 upstream.

Not having power is a pretty serious error so check that we are able to
enable the supply and error out if we can't.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
drm/radeon: add primary dac adj quirk for R200 board

BugLink: http://bugs.launchpad.net/bugs/1155651

commit e8fc41377f5037ff7a661ea06adc05f1daec1548 upstream.

vbios values are wrong leading to colors that are
too bright.  Use the default values instead.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
ALSA: ice1712: Initialize card->private_data properly

BugLink: http://bugs.launchpad.net/bugs/1155651

commit 69a4cfdd444d1fe5c24d29b3a063964ac165d2cd upstream.

Set card->private_data in snd_ice1712_create for fixing NULL
dereference in snd_ice1712_remove().

Signed-off-by: Sean Connor <sconnor004@allyinics.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
ALSA: vmaster: Fix slave change notification

BugLink: http://bugs.launchpad.net/bugs/1155651

commit 2069d483b39a603a5f3428a19d3b4ac89aa97f48 upstream.

When a value of a vmaster slave control is changed, the ctl change
notification is sometimes ignored.  This happens when the master
control overrides, e.g. when the corresponding master control is
muted.  The reason is that slave_put() returns the value of the actual
slave put callback, and it doesn't reflect the virtual slave value
change.

This patch fixes the function just to return 1 whenever a slave value
is changed.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
e1000e: fix pci-device enable-counter balance

BugLink: http://bugs.launchpad.net/bugs/1155651

commit 4e0855dff094b0d56d6b5b271e0ce7851cc1e063 upstream.

This patch removes redundant and unbalanced pci_disable_device() from
__e1000_shutdown(). pci_clear_master() is enough, device can go into
suspended state with elevated enable_cnt.

Bug was introduced in commit 23606cf5d1192c2b17912cb2ef6e62f9b11de133
("e1000e / PCI / PM: Add basic runtime PM support (rev. 4)") in v2.6.35

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Bruce Allan <bruce.w.allan@intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Borislav Petkov <bp@suse.de>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
vfs: fix pipe counter breakage

BugLink: http://bugs.launchpad.net/bugs/1155651

commit a930d8790552658140d7d0d2e316af4f0d76a512 upstream.

If you open a pipe for neither read nor write, the pipe code will not
add any usage counters to the pipe, causing the 'struct pipe_inode_info"
to be potentially released early.

That doesn't normally matter, since you cannot actually use the pipe,
but the pipe release code - particularly fasync handling - still expects
the actual pipe infrastructure to all be there.  And rather than adding
NULL pointer checks, let's just disallow this case, the same way we
already do for the named pipe ("fifo") case.

This is ancient going back to pre-2.4 days, and until trinity, nobody
naver noticed.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
Fix memory leak in cpufreq stats.

BugLink: http://bugs.launchpad.net/bugs/1155651

commit e37736777254ce1abc85493a5cacbefe5983b896 upstream.

When system enters sleep, non-boot CPUs will be disabled.
Cpufreq stats sysfs is created when the CPU is up, but it is not
freed when the CPU is going down. This will cause memory leak.

Signed-off-by: xiaobing tu <xiaobing.tu@intel.com>
Signed-off-by: guifang tang <guifang.tang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Colin Cross <ccross@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
ftrace: Update the kconfig for DYNAMIC_FTRACE

BugLink: http://bugs.launchpad.net/bugs/1155651

commit db05021d49a994ee40a9735d9c3cb0060c9babb8 upstream.

The prompt to enable DYNAMIC_FTRACE (the ability to nop and
enable function tracing at run time) had a confusing statement:

 "enable/disable ftrace tracepoints dynamically"

This was written before tracepoints were added to the kernel,
but now that tracepoints have been added, this is very confusing
and has confused people enough to give wrong information during
presentations.

Not only that, I looked at the help text, and it still references
that dreaded daemon that use to wake up once a second to update
the nop locations and brick NICs, that hasn't been around for over
five years.

Time to bring the text up to the current decade.

Reported-by: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>
decnet: Fix disappearing sysctl entries

BugLink: http://bugs.launchpad.net/bugs/1155651

When decnet is built as a module a simple:
echo 0.0 >/proc/sys/net/decnet/node_address

results in most of the sysctl entries under /proc/sys/net/decnet and
/proc/sys/net/decnet/conf disappearing.

For more details see http://www.spinics.net/lists/netdev/msg226123.html.

This change applies the same workaround used in
net/core/sysctl_net_core.c and net/ipv6/sysctl_net_ipv6.c of creating
a skeleton of decnet sysctl entries before doing anything else.

The problem first appeared in kernel 2.6.27.  The later rewrite of
sysctl in kernel 3.4 restored the previous behavior and eliminated the
need for this workaround.

This patch was heavily inspired by a similar but more complex patch by
Larry Baker.

Reported-by: Larry Baker <baker@usgs.gov>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: David Miller <davem@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brad Figg <brad.figg@canonical.com>