linux-stable.git/drivers, branch v3.16.40

sg_write()/bsg_write() is not fit to be called under KERNEL_DS

2017-02-23T03:54:47+00:00

commit 128394eff343fc6d2f32172f03e24829539c5835 upstream.

Both damn things interpret userland pointers embedded into the payload;
worse, they are actually traversing those.  Leaving aside the bad
API design, this is very much _not_ safe to call with KERNEL_DS.
Bail out early if that happens.

Signed-off-by: Al Viro 
Signed-off-by: Ben Hutchings

staging/android/ion : fix a race condition in the ion driver

2017-02-23T03:54:47+00:00

commit 9590232bb4f4cc824f3425a6e1349afbe6d6d2b7 upstream.

There is a use-after-free problem in the ion driver.
This is caused by a race condition in the ion_ioctl()
function.

A handle has ref count of 1 and two tasks on different
cpus calls ION_IOC_FREE simultaneously.

cpu 0                                   cpu 1
-------------------------------------------------------
ion_handle_get_by_id()
(ref == 2)
                            ion_handle_get_by_id()
                            (ref == 3)

ion_free()
(ref == 2)

ion_handle_put()
(ref == 1)

                            ion_free()
                            (ref == 0 so ion_handle_destroy() is
                            called
                            and the handle is freed.)

                            ion_handle_put() is called and it
                            decreases the slub's next free pointer

The problem is detected as an unaligned access in the
spin lock functions since it uses load exclusive
 instruction. In some cases it corrupts the slub's
free pointer which causes a mis-aligned access to the
next free pointer.(kmalloc returns a pointer like
ffffc0745b4580aa). And it causes lots of other
hard-to-debug problems.

This symptom is caused since the first member in the
ion_handle structure is the reference count and the
ion driver decrements the reference after it has been
freed.

To fix this problem client->lock mutex is extended
to protect all the codes that uses the handle.

Signed-off-by: Eun Taik Lee 
Reviewed-by: Laura Abbott 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

fbdev: color map copying bounds checking

2017-02-23T03:54:46+00:00

commit 2dc705a9930b4806250fbf5a76e55266e59389f2 upstream.

Copying color maps to userspace doesn't check the value of to->start,
which will cause kernel heap buffer OOB read due to signedness wraps.

CVE-2016-8405

Link: http://lkml.kernel.org/r/20170105224249.GA50925@beast
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kees Cook 
Reported-by: Peter Pi (@heisecode) of Trend Micro
Cc: Min Chong 
Cc: Dan Carpenter 
Cc: Tomi Valkeinen 
Cc: Bartlomiej Zolnierkiewicz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

HID: core: prevent out-of-bound readings

2017-02-23T03:54:45+00:00

commit 50220dead1650609206efe91f0cc116132d59b3f upstream.

Plugging a Logitech DJ receiver with KASAN activated raises a bunch of
out-of-bound readings.

The fields are allocated up to MAX_USAGE, meaning that potentially, we do
not have enough fields to fit the incoming values.
Add checks and silence KASAN.

Signed-off-by: Benjamin Tissoires 
Signed-off-by: Jiri Kosina 
Signed-off-by: Ben Hutchings

usb: gadget: f_fs: Fix use-after-free

2017-02-23T03:54:45+00:00

commit 38740a5b87d53ceb89eb2c970150f6e94e00373a upstream.

When using asynchronous read or write operations on the USB endpoints the
issuer of the IO request is notified by calling the ki_complete() callback
of the submitted kiocb when the URB has been completed.

Calling this ki_complete() callback will free kiocb. Make sure that the
structure is no longer accessed beyond that point, otherwise undefined
behaviour might occur.

Fixes: 2e4c7553cd6f ("usb: gadget: f_fs: add aio support")
Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Felipe Balbi 
[bwh: Backported to 3.16:
 - Adjust filename
 - We only use kiocb::private, not kiocb::ki_flags]
Signed-off-by: Ben Hutchings

tty: Prevent ldisc drivers from re-using stale tty fields

2017-02-23T03:54:44+00:00

commit dd42bf1197144ede075a9d4793123f7689e164bc upstream.

Line discipline drivers may mistakenly misuse ldisc-related fields
when initializing. For example, a failure to initialize tty->receive_room
in the N_GIGASET_M101 line discipline was recently found and fixed [1].
Now, the N_X25 line discipline has been discovered accessing the previous
line discipline's already-freed private data [2].

Harden the ldisc interface against misuse by initializing revelant
tty fields before instancing the new line discipline.

[1]
    commit fd98e9419d8d622a4de91f76b306af6aa627aa9c
    Author: Tilman Schmidt 
    Date:   Tue Jul 14 00:37:13 2015 +0200

    isdn/gigaset: reset tty->receive_room when attaching ser_gigaset

[2] Report from Sasha Levin 
    [  634.336761] ==================================================================
    [  634.338226] BUG: KASAN: use-after-free in x25_asy_open_tty+0x13d/0x490 at addr ffff8800a743efd0
    [  634.339558] Read of size 4 by task syzkaller_execu/8981
    [  634.340359] =============================================================================
    [  634.341598] BUG kmalloc-512 (Not tainted): kasan: bad access detected
    ...
    [  634.405018] Call Trace:
    [  634.405277] dump_stack (lib/dump_stack.c:52)
    [  634.405775] print_trailer (mm/slub.c:655)
    [  634.406361] object_err (mm/slub.c:662)
    [  634.406824] kasan_report_error (mm/kasan/report.c:138 mm/kasan/report.c:236)
    [  634.409581] __asan_report_load4_noabort (mm/kasan/report.c:279)
    [  634.411355] x25_asy_open_tty (drivers/net/wan/x25_asy.c:559 (discriminator 1))
    [  634.413997] tty_ldisc_open.isra.2 (drivers/tty/tty_ldisc.c:447)
    [  634.414549] tty_set_ldisc (drivers/tty/tty_ldisc.c:567)
    [  634.415057] tty_ioctl (drivers/tty/tty_io.c:2646 drivers/tty/tty_io.c:2879)
    [  634.423524] do_vfs_ioctl (fs/ioctl.c:43 fs/ioctl.c:607)
    [  634.427491] SyS_ioctl (fs/ioctl.c:622 fs/ioctl.c:613)
    [  634.427945] entry_SYSCALL_64_fastpath (arch/x86/entry/entry_64.S:188)

Cc: Tilman Schmidt 
Cc: Sasha Levin 
Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

sg: Fix double-free when drives detach during SG_IO

2017-02-23T03:54:44+00:00

commit f3951a3709ff50990bf3e188c27d346792103432 upstream.

In sg_common_write(), we free the block request and return -ENODEV if
the device is detached in the middle of the SG_IO ioctl().

Unfortunately, sg_finish_rem_req() also tries to free srp->rq, so we
end up freeing rq->cmd in the already free rq object, and then free
the object itself out from under the current user.

This ends up corrupting random memory via the list_head on the rq
object. The most common crash trace I saw is this:

  ------------[ cut here ]------------
  kernel BUG at block/blk-core.c:1420!
  Call Trace:
  [] blk_put_request+0x5b/0x80
  [] sg_finish_rem_req+0x6b/0x120 [sg]
  [] sg_common_write.isra.14+0x459/0x5a0 [sg]
  [] ? selinux_file_alloc_security+0x48/0x70
  [] sg_new_write.isra.17+0x195/0x2d0 [sg]
  [] sg_ioctl+0x644/0xdb0 [sg]
  [] do_vfs_ioctl+0x90/0x520
  [] ? file_has_perm+0x97/0xb0
  [] SyS_ioctl+0x91/0xb0
  [] tracesys+0xdd/0xe2
    RIP [] __blk_put_request+0x154/0x1a0

The solution is straightforward: just set srp->rq to NULL in the
failure branch so that sg_finish_rem_req() doesn't attempt to re-free
it.

Additionally, since sg_rq_end_io() will never be called on the object
when this happens, we need to free memory backing ->cmd if it isn't
embedded in the object itself.

KASAN was extremely helpful in finding the root cause of this bug.

Signed-off-by: Calvin Owens 
Acked-by: Douglas Gilbert 
Signed-off-by: Martin K. Petersen 
[bwh: Backported to 3.16:
 - sg_finish_rem_req() would not free srp->rq->cmd so don't do it here either
 - Adjust context]
Signed-off-by: Ben Hutchings

ser_gigaset: return -ENOMEM on error instead of success

2017-02-23T03:54:44+00:00

commit 93a97c50cbf1c007caf12db5cc23e0d5b9c8473c upstream.

If we can't allocate the resources in gigaset_initdriver() then we
should return -ENOMEM instead of zero.

Fixes: 2869b23e4b95 ("[PATCH] drivers/isdn/gigaset: new M101 driver (v2)")
Signed-off-by: Dan Carpenter 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

can: peak: fix bad memory access and free sequence

2017-02-23T03:54:44+00:00

commit b67d0dd7d0dc9e456825447bbeb935d8ef43ea7c upstream.

Fix for bad memory access while disconnecting. netdev is freed before
private data free, and dev is accessed after freeing netdev.

This makes a slub problem, and it raise kernel oops with slub debugger
config.

Signed-off-by: Jiho Chu 
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Ben Hutchings

net: ep93xx_eth: Do not crash unloading module

2017-02-23T03:54:42+00:00

commit c823abac17926767fb50175e098f087a6ac684c3 upstream.

When we unload the ep93xx_eth, whether we have opened the network
interface or not, we will either hit a kernel paging request error, or a
simple NULL pointer de-reference because:

- if ep93xx_open has been called, we have created a valid DMA mapping
  for ep->descs, when we call ep93xx_stop, we also call
  ep93xx_free_buffers, ep->descs now has a stale value

- if ep93xx_open has not been called, we have a NULL pointer for
  ep->descs, so performing any operation against that address just won't
  work

Fix this by adding a NULL pointer check for ep->descs which means that
ep93xx_free_buffers() was able to successfully tear down the descriptors
and free the DMA cookie as well.

Fixes: 1d22e05df818 ("[PATCH] Cirrus Logic ep93xx ethernet driver")
Signed-off-by: Florian Fainelli 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings