linux-toradex.git/include/linux, branch v4.4.26

mm: remove gup_flags FOLL_WRITE games from __get_user_pages()

2016-10-20T08:00:47+00:00

commit 19be0eaffa3ac7d8eb6784ad9bdbc7d67ed8e619 upstream.

This is an ancient bug that was actually attempted to be fixed once
(badly) by me eleven years ago in commit 4ceb5db9757a ("Fix
get_user_pages() race for write access") but that was then undone due to
problems on s390 by commit f33ea7f404e5 ("fix get_user_pages bug").

In the meantime, the s390 situation has long been fixed, and we can now
fix it by checking the pte_dirty() bit properly (and do it better).  The
s390 dirty bit was implemented in abf09bed3cce ("s390/mm: implement
software dirty bits") which made it into v3.9.  Earlier kernels will
have to look at the page state itself.

Also, the VM has become more scalable, and what used a purely
theoretical race back then has become easier to trigger.

To fix it, we introduce a new internal FOLL_COW flag to mark the "yes,
we already did a COW" rather than play racy games with FOLL_WRITE that
is very fundamental, and then use the pte dirty flag to validate that
the FOLL_COW flag is still valid.

Reported-and-tested-by: Phil "not Paul" Oester 
Acked-by: Hugh Dickins 
Reviewed-by: Michal Hocko 
Cc: Andy Lutomirski 
Cc: Kees Cook 
Cc: Oleg Nesterov 
Cc: Willy Tarreau 
Cc: Nick Piggin 
Cc: Greg Thelen 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mfd: 88pm80x: Double shifting bug in suspend/resume

2016-10-16T15:36:14+00:00

commit 9a6dc644512fd083400a96ac4a035ac154fe6b8d upstream.

set_bit() and clear_bit() take the bit number so this code is really
doing "1 << (1 << irq)" which is a double shift bug.  It's done
consistently so it won't cause a problem unless "irq" is more than 4.

Fixes: 70c6cce04066 ('mfd: Support 88pm80x in 80x driver')
Signed-off-by: Dan Carpenter 
Signed-off-by: Lee Jones 
Signed-off-by: Greg Kroah-Hartman

sysctl: handle error writing UINT_MAX to u32 fields

2016-10-07T13:23:46+00:00

commit e7d316a02f683864a12389f8808570e37fb90aa3 upstream.

We have scripts which write to certain fields on 3.18 kernels but this
seems to be failing on 4.4 kernels.  An entry which we write to here is
xfrm_aevent_rseqth which is u32.

  echo 4294967295  > /proc/sys/net/core/xfrm_aevent_rseqth

Commit 230633d109e3 ("kernel/sysctl.c: detect overflows when converting
to int") prevented writing to sysctl entries when integer overflow
occurs.  However, this does not apply to unsigned integers.

Heinrich suggested that we introduce a new option to handle 64 bit
limits and set min as 0 and max as UINT_MAX.  This might not work as it
leads to issues similar to __do_proc_doulongvec_minmax.  Alternatively,
we would need to change the datatype of the entry to 64 bit.

  static int __do_proc_doulongvec_minmax(void *data, struct ctl_table
  {
      i = (unsigned long *) data;   //This cast is causing to read beyond the size of data (u32)
      vleft = table->maxlen / sizeof(unsigned long); //vleft is 0 because maxlen is sizeof(u32) which is lesser than sizeof(unsigned long) on x86_64.

Introduce a new proc handler proc_douintvec.  Individual proc entries
will need to be updated to use the new handler.

[akpm@linux-foundation.org: coding-style fixes]
Fixes: 230633d109e3 ("kernel/sysctl.c:detect overflows when converting to int")
Link: http://lkml.kernel.org/r/1471479806-5252-1-git-send-email-subashab@codeaurora.org
Signed-off-by: Subash Abhinov Kasiviswanathan 
Cc: Heinrich Schuchardt 
Cc: Kees Cook 
Cc: "David S. Miller" 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

nvmem: Declare nvmem_cell_read() consistently

2016-10-07T13:23:41+00:00

commit a6c50912508d80164a5e607993b617be85a46d73 upstream.

nvmem_cell_read() is declared as void * if CONFIG_NVMEM is enabled, and
as char * otherwise. This can result in a build warning if CONFIG_NVMEM
is not enabled and a caller asigns the result to a type other than char *
without using a typecast. Use a consistent declaration to avoid the
problem.

Fixes: e2a5402ec7c6 ("nvmem: Add nvmem_device based consumer apis.")
Cc: Srinivas Kandagatla 
Signed-off-by: Guenter Roeck 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

can: dev: fix deadlock reported after bus-off

2016-10-07T13:23:40+00:00

commit 9abefcb1aaa58b9d5aa40a8bb12c87d02415e4c8 upstream.

A timer was used to restart after the bus-off state, leading to a
relatively large can_restart() executed in an interrupt context,
which in turn sets up pinctrl. When this happens during system boot,
there is a high probability of grabbing the pinctrl_list_mutex,
which is locked already by the probe() of other device, making the
kernel suspect a deadlock condition [1].

To resolve this issue, the restart_timer is replaced by a delayed
work.

[1] https://github.com/victronenergy/venus/issues/24

Signed-off-by: Sergei Miroshnichenko 
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Greg Kroah-Hartman

fix fault_in_multipages_...() on architectures with no-op access_ok()

2016-09-30T08:18:37+00:00

commit e23d4159b109167126e5bcd7f3775c95de7fee47 upstream.

Switching iov_iter fault-in to multipages variants has exposed an old
bug in underlying fault_in_multipages_...(); they break if the range
passed to them wraps around.  Normally access_ok() done by callers will
prevent such (and it's a guaranteed EFAULT - ERR_PTR() values fall into
such a range and they should not point to any valid objects).

However, on architectures where userland and kernel live in different
MMU contexts (e.g. s390) access_ok() is a no-op and on those a range
with a wraparound can reach fault_in_multipages_...().

Since any wraparound means EFAULT there, the fix is trivial - turn
those

    while (uaddr <= end)
	    ...
into

    if (unlikely(uaddr > end))
	    return -EFAULT;
    do
	    ...
    while (uaddr <= end);

Reported-by: Jan Stancek 
Tested-by: Jan Stancek 
Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

fanotify: fix list corruption in fanotify_get_response()

2016-09-30T08:18:37+00:00

commit 96d41019e3ac55f6f0115b0ce97e4f24a3d636d2 upstream.

fanotify_get_response() calls fsnotify_remove_event() when it finds that
group is being released from fanotify_release() (bypass_perm is set).

However the event it removes need not be only in the group's notification
queue but it can have already moved to access_list (userspace read the
event before closing the fanotify instance fd) which is protected by a
different lock.  Thus when fsnotify_remove_event() races with
fanotify_release() operating on access_list, the list can get corrupted.

Fix the problem by moving all the logic removing permission events from
the lists to one place - fanotify_release().

Fixes: 5838d4442bd5 ("fanotify: fix double free of pending permission events")
Link: http://lkml.kernel.org/r/1473797711-14111-3-git-send-email-jack@suse.cz
Signed-off-by: Jan Kara 
Reported-by: Miklos Szeredi 
Tested-by: Miklos Szeredi 
Reviewed-by: Miklos Szeredi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

fsnotify: add a way to stop queueing events on group shutdown

2016-09-30T08:18:37+00:00

commit 12703dbfeb15402260e7554d32a34ac40c233990 upstream.

Implement a function that can be called when a group is being shutdown
to stop queueing new events to the group.  Fanotify will use this.

Fixes: 5838d4442bd5 ("fanotify: fix double free of pending permission events")
Link: http://lkml.kernel.org/r/1473797711-14111-2-git-send-email-jack@suse.cz
Signed-off-by: Jan Kara 
Reviewed-by: Miklos Szeredi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

net: smc91x: fix SMC accesses

2016-09-30T08:18:37+00:00

[ Upstream commit 2fb04fdf30192ff1e2b5834e9b7745889ea8bbcb ]

Commit b70661c70830 ("net: smc91x: use run-time configuration on all ARM
machines") broke some ARM platforms through several mistakes.  Firstly,
the access size must correspond to the following rule:

(a) at least one of 16-bit or 8-bit access size must be supported
(b) 32-bit accesses are optional, and may be enabled in addition to
    the above.

Secondly, it provides no emulation of 16-bit accesses, instead blindly
making 16-bit accesses even when the platform specifies that only 8-bit
is supported.

Reorganise smc91x.h so we can make use of the existing 16-bit access
emulation already provided - if 16-bit accesses are supported, use
16-bit accesses directly, otherwise if 8-bit accesses are supported,
use the provided 16-bit access emulation.  If neither, BUG().  This
exactly reflects the driver behaviour prior to the commit being fixed.

Since the conversion incorrectly cut down the available access sizes on
several platforms, we also need to go through every platform and fix up
the overly-restrictive access size: Arnd assumed that if a platform can
perform 32-bit, 16-bit and 8-bit accesses, then only a 32-bit access
size needed to be specified - not so, all available access sizes must
be specified.

This likely fixes some performance regressions in doing this: if a
platform does not support 8-bit accesses, 8-bit accesses have been
emulated by performing a 16-bit read-modify-write access.

Tested on the Intel Assabet/Neponset platform, which supports only 8-bit
accesses, which was broken by the original commit.

Fixes: b70661c70830 ("net: smc91x: use run-time configuration on all ARM machines")
Signed-off-by: Russell King 
Tested-by: Robert Jarzmik 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

bonding: Fix bonding crash

2016-09-30T08:18:36+00:00

[ Upstream commit 24b27fc4cdf9e10c5e79e5923b6b7c2c5c95096c ]

Following few steps will crash kernel -

  (a) Create bonding master
      > modprobe bonding miimon=50
  (b) Create macvlan bridge on eth2
      > ip link add link eth2 dev mvl0 address aa:0:0:0:0:01 \
	   type macvlan
  (c) Now try adding eth2 into the bond
      > echo +eth2 > /sys/class/net/bond0/bonding/slaves
      

Bonding does lots of things before checking if the device enslaved is
busy or not.

In this case when the notifier call-chain sends notifications, the
bond_netdev_event() assumes that the rx_handler /rx_handler_data is
registered while the bond_enslave() hasn't progressed far enough to
register rx_handler for the new slave.

This patch adds a rx_handler check that can be performed right at the
beginning of the enslave code to avoid getting into this situation.

Signed-off-by: Mahesh Bandewar 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman