linux-toradex.git/drivers, branch v2.6.32.69

HID: core: Avoid uninitialized buffer access

2015-12-05T23:49:17+00:00

commit 79b568b9d0c7c5d81932f4486d50b38efdd6da6d upstream.

hid_connect adds various strings to the buffer but they're all
conditional. You can find circumstances where nothing would be written
to it but the kernel will still print the supposedly empty buffer with
printk. This leads to corruption on the console/in the logs.

Ensure buf is initialized to an empty string.

Signed-off-by: Richard Purdie 
[dvhart: Initialize string to "" rather than assign buf[0] = NULL;]
Cc: Jiri Kosina 
Cc: linux-input@vger.kernel.org
Signed-off-by: Darren Hart 
Signed-off-by: Jiri Kosina 
Signed-off-by: Ben Hutchings 
(cherry picked from commit 604bfd00358e3d7fce8dc789fe52d2f2be0fa4c7)

Signed-off-by: Willy Tarreau

mvsas: Fix NULL pointer dereference in mvs_slot_task_free

2015-12-05T23:49:15+00:00

commit 2280521719e81919283b82902ac24058f87dfc1b upstream.

When pci_pool_alloc fails in mvs_task_prep then task->lldd_task stays
NULL but it's later used in mvs_abort_task as slot which is passed
to mvs_slot_task_free causing NULL pointer dereference.

Just return from mvs_slot_task_free when passed with NULL slot.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=101891
Signed-off-by: DÄvis MosÄns 
Reviewed-by: Tomas Henzl 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: James Bottomley 
Signed-off-by: Ben Hutchings 
(cherry picked from commit cc1875ecbc3c9fb2774097e03870280c91c1e0e1)

Signed-off-by: Willy Tarreau

tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.c

2015-12-05T23:49:15+00:00

commit e81107d4c6bd098878af9796b24edc8d4a9524fd upstream.

My colleague ran into a program stall on a x86_64 server, where
n_tty_read() was waiting for data even if there was data in the buffer
in the pty.  kernel stack for the stuck process looks like below.
 #0 [ffff88303d107b58] __schedule at ffffffff815c4b20
 #1 [ffff88303d107bd0] schedule at ffffffff815c513e
 #2 [ffff88303d107bf0] schedule_timeout at ffffffff815c7818
 #3 [ffff88303d107ca0] wait_woken at ffffffff81096bd2
 #4 [ffff88303d107ce0] n_tty_read at ffffffff8136fa23
 #5 [ffff88303d107dd0] tty_read at ffffffff81368013
 #6 [ffff88303d107e20] __vfs_read at ffffffff811a3704
 #7 [ffff88303d107ec0] vfs_read at ffffffff811a3a57
 #8 [ffff88303d107f00] sys_read at ffffffff811a4306
 #9 [ffff88303d107f50] entry_SYSCALL_64_fastpath at ffffffff815c86d7

There seems to be two problems causing this issue.

First, in drivers/tty/n_tty.c, __receive_buf() stores the data and
updates ldata->commit_head using smp_store_release() and then checks
the wait queue using waitqueue_active().  However, since there is no
memory barrier, __receive_buf() could return without calling
wake_up_interactive_poll(), and at the same time, n_tty_read() could
start to wait in wait_woken() as in the following chart.

        __receive_buf()                         n_tty_read()
------------------------------------------------------------------------
if (waitqueue_active(&tty->read_wait))
/* Memory operations issued after the
   RELEASE may be completed before the
   RELEASE operation has completed */
                                        add_wait_queue(&tty->read_wait, &wait);
                                        ...
                                        if (!input_available_p(tty, 0)) {
smp_store_release(&ldata->commit_head,
                  ldata->read_head);
                                        ...
                                        timeout = wait_woken(&wait,
                                          TASK_INTERRUPTIBLE, timeout);
------------------------------------------------------------------------

The second problem is that n_tty_read() also lacks a memory barrier
call and could also cause __receive_buf() to return without calling
wake_up_interactive_poll(), and n_tty_read() to wait in wait_woken()
as in the chart below.

        __receive_buf()                         n_tty_read()
------------------------------------------------------------------------
                                        spin_lock_irqsave(&q->lock, flags);
                                        /* from add_wait_queue() */
                                        ...
                                        if (!input_available_p(tty, 0)) {
                                        /* Memory operations issued after the
                                           RELEASE may be completed before the
                                           RELEASE operation has completed */
smp_store_release(&ldata->commit_head,
                  ldata->read_head);
if (waitqueue_active(&tty->read_wait))
                                        __add_wait_queue(q, wait);
                                        spin_unlock_irqrestore(&q->lock,flags);
                                        /* from add_wait_queue() */
                                        ...
                                        timeout = wait_woken(&wait,
                                          TASK_INTERRUPTIBLE, timeout);
------------------------------------------------------------------------

There are also other places in drivers/tty/n_tty.c which have similar
calls to waitqueue_active(), so instead of adding many memory barrier
calls, this patch simply removes the call to waitqueue_active(),
leaving just wake_up*() behind.

This fixes both problems because, even though the memory access before
or after the spinlocks in both wake_up*() and add_wait_queue() can
sneak into the critical section, it cannot go past it and the critical
section assures that they will be serialized (please see "INTER-CPU
ACQUIRING BARRIER EFFECTS" in Documentation/memory-barriers.txt for a
better explanation).  Moreover, the resulting code is much simpler.

Latency measurement using a ping-pong test over a pty doesn't show any
visible performance drop.

Signed-off-by: Kosuke Tatsukawa 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2:
 - Use wake_up_interruptible(), not wake_up_interruptible_poll()
 - There are only two spurious uses of waitqueue_active() to remove]
Signed-off-by: Ben Hutchings 
(cherry picked from commit 80910ccdd3ee35e4131df38bc73b86ee60abdf0b)
[wt: file is drivers/char/n_tty.c in 2.6.32]
Signed-off-by: Willy Tarreau

Input: evdev - do not report errors form flush()

2015-12-05T23:49:09+00:00

commit eb38f3a4f6e86f8bb10a3217ebd85ecc5d763aae upstream.

We've got bug reports showing the old systemd-logind (at least
system-210) aborting unexpectedly, and this turned out to be because
of an invalid error code from close() call to evdev devices.  close()
is supposed to return only either EINTR or EBADFD, while the device
returned ENODEV.  logind was overreacting to it and decided to kill
itself when an unexpected error code was received.  What a tragedy.

The bad error code comes from flush fops, and actually evdev_flush()
returns ENODEV when device is disconnected or client's access to it is
revoked. But in these cases the fact that flush did not actually happen is
not an error, but rather normal behavior. For non-disconnected devices
result of flush is also not that interesting as there is no potential of
data loss and even if it fails application has no way of handling the
error. Because of that we are better off always returning success from
evdev_flush().

Also returning EINTR from flush()/close() is discouraged (as it is not
clear how application should handle this error), so let's stop taking
evdev->mutex interruptibly.

Bugzilla: http://bugzilla.suse.com/show_bug.cgi?id=939834
Signed-off-by: Takashi Iwai 
Signed-off-by: Dmitry Torokhov 
[bwh: Backported to 3.2: there's no revoked flag to test]
Signed-off-by: Ben Hutchings 
(cherry picked from commit a6706174cfe9fa100651b5012aec9796006a884b)

Signed-off-by: Willy Tarreau

windfarm: decrement client count when unregistering

2015-12-05T23:49:07+00:00

commit fe2b592173ff0274e70dc44d1d28c19bb995aa7c upstream.

wf_unregister_client() increments the client count when a client
unregisters. That is obviously incorrect. Decrement that client count
instead.

Fixes: 75722d3992f5 ("[PATCH] ppc64: Thermal control for SMU based machines")

Signed-off-by: Paul Bolle 
Signed-off-by: Michael Ellerman 
Signed-off-by: Ben Hutchings 
(cherry picked from commit 48c46d4aed1c27f363e4673e988212340e82e1bb)
Signed-off-by: Willy Tarreau

devres: fix devres_get()

2015-12-05T23:49:07+00:00

commit 64526370d11ce8868ca495723d595b61e8697fbf upstream.

Currently, devres_get() passes devres_free() the pointer to devres,
but devres_free() should be given with the pointer to resource data.

Fixes: 9ac7849e35f7 ("devres: device resource management")
Signed-off-by: Masahiro Yamada 
Acked-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings 
(cherry picked from commit ebc0ae5a7159086a992f7904dc9ad849a13eecfc)
Signed-off-by: Willy Tarreau

xhci: fix off by one error in TRB DMA address boundary check

2015-12-05T23:49:04+00:00

commit 7895086afde2a05fa24a0e410d8e6b75ca7c8fdd upstream.

We need to check that a TRB is part of the current segment
before calculating its DMA address.

Previously a ring segment didn't use a full memory page, and every
new ring segment got a new memory page, so the off by one
error in checking the upper bound was never seen.

Now that we use a full memory page, 256 TRBs (4096 bytes), the off by one
didn't catch the case when a TRB was the first element of the next segment.

This is triggered if the virtual memory pages for a ring segment are
next to each in increasing order where the ring buffer wraps around and
causes errors like:

[  106.398223] xhci_hcd 0000:00:14.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 0 comp_code 1
[  106.398230] xhci_hcd 0000:00:14.0: Looking for event-dma fffd3000 trb-start fffd4fd0 trb-end fffd5000 seg-start fffd4000 seg-end fffd4ff0

The trb-end address is one outside the end-seg address.

Tested-by: Arkadiusz MiÅkiewicz 
Signed-off-by: Mathias Nyman 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings 
(cherry picked from commit 6e3ae6256145b5597bee0296eb5fc384cd86aa3d)
Signed-off-by: Willy Tarreau

USB: whiteheat: fix potential null-deref at probe

2015-12-05T23:49:03+00:00

commit cbb4be652d374f64661137756b8f357a1827d6a4 upstream.

Fix potential null-pointer dereference at probe by making sure that the
required endpoints are present.

The whiteheat driver assumes there are at least five pairs of bulk
endpoints, of which the final pair is used for the "command port". An
attempt to bind to an interface with fewer bulk endpoints would
currently lead to an oops.

Fixes CVE-2015-5257.

Reported-by: Moein Ghasemzadeh 
Signed-off-by: Johan Hovold 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings 
Signed-off-by: Willy Tarreau

virtio-net: drop NETIF_F_FRAGLIST

2015-12-05T23:49:02+00:00

commit 48900cb6af4282fa0fb6ff4d72a81aa3dadb5c39 upstream.

virtio declares support for NETIF_F_FRAGLIST, but assumes
that there are at most MAX_SKB_FRAGS + 2 fragments which isn't
always true with a fraglist.

A longer fraglist in the skb will make the call to skb_to_sgvec overflow
the sg array, leading to memory corruption.

Drop NETIF_F_FRAGLIST so we only get what we can handle.

Cc: Michael S. Tsirkin 
Signed-off-by: Jason Wang 
Acked-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller 
[bwh: Backported to 2.6.32: there's only a single features field]
Signed-off-by: Ben Hutchings 
Signed-off-by: Willy Tarreau

md: use kzalloc() when bitmap is disabled

2015-12-05T23:49:01+00:00

commit b6878d9e03043695dbf3fa1caa6dfc09db225b16 upstream.

In drivers/md/md.c get_bitmap_file() uses kmalloc() for creating a
mdu_bitmap_file_t called "file".

5769         file = kmalloc(sizeof(*file), GFP_NOIO);
5770         if (!file)
5771                 return -ENOMEM;

This structure is copied to user space at the end of the function.

5786         if (err == 0 &&
5787             copy_to_user(arg, file, sizeof(*file)))
5788                 err = -EFAULT

But if bitmap is disabled only the first byte of "file" is initialized
with zero, so it's possible to read some bytes (up to 4095) of kernel
space memory from user space. This is an information leak.

5775         /* bitmap disabled, zero the first byte and copy out */
5776         if (!mddev->bitmap_info.file)
5777                 file->pathname[0] = '\0';

Signed-off-by: Benjamin Randazzo 
Signed-off-by: NeilBrown 
[bwh: Backported to 2.6.32: patch both possible allocation calls]
Signed-off-by: Ben Hutchings 
Signed-off-by: Willy Tarreau