linux-stable.git/include, branch v3.16.79

appletalk: Fix potential NULL pointer dereference in unregister_snap_client

2019-12-10T18:01:33+00:00

commit 9804501fa1228048857910a6bf23e085aade37cc upstream.

register_snap_client may return NULL, all the callers
check it, but only print a warning. This will result in
NULL pointer dereference in unregister_snap_client and other
places.

It has always been used like this since v2.6

Reported-by: Dan Carpenter 
Signed-off-by: YueHaibing 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

cfg80211: add and use strongly typed element iteration macros

2019-12-10T18:01:28+00:00

commit 0f3b07f027f87a38ebe5c436490095df762819be upstream.

Rather than always iterating elements from frames with pure
u8 pointers, add a type "struct element" that encapsulates
the id/datalen/data format of them.

Then, add the element iteration macros
 * for_each_element
 * for_each_element_id
 * for_each_element_extid

which take, as their first 'argument', such a structure and
iterate through a given u8 array interpreting it as elements.

While at it and since we'll need it, also add
 * for_each_subelement
 * for_each_subelement_id
 * for_each_subelement_extid

which instead of taking data/length just take an outer element
and use its data/datalen.

Also add for_each_element_completed() to determine if any of
the loops above completed, i.e. it was able to parse all of
the elements successfully and no data remained.

Use for_each_element_id() in cfg80211_find_ie_match() as the
first user of this.

Signed-off-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

ASoC: Define a set of DAPM pre/post-up events

2019-12-10T18:01:07+00:00

commit cfc8f568aada98f9608a0a62511ca18d647613e2 upstream.

Prepare to use SND_SOC_DAPM_PRE_POST_PMU definition to
reduce coming code size and make it more readable.

Signed-off-by: Oleksandr Suvorov 
Reviewed-by: Marcel Ziswiler 
Reviewed-by: Igor Opaniuk 
Reviewed-by: Fabio Estevam 
Link: https://lore.kernel.org/r/20190719100524.23300-2-oleksandr.suvorov@toradex.com
Signed-off-by: Mark Brown 
Signed-off-by: Ben Hutchings

asm-generic: fix -Wtype-limits compiler warnings

2019-11-22T15:57:11+00:00

commit cbedfe11347fe418621bd188d58a206beb676218 upstream.

Commit d66acc39c7ce ("bitops: Optimise get_order()") introduced a
compilation warning because "rx_frag_size" is an "ushort" while
PAGE_SHIFT here is 16.

The commit changed the get_order() to be a multi-line macro where
compilers insist to check all statements in the macro even when
__builtin_constant_p(rx_frag_size) will return false as "rx_frag_size"
is a module parameter.

In file included from ./arch/powerpc/include/asm/page_64.h:107,
                 from ./arch/powerpc/include/asm/page.h:242,
                 from ./arch/powerpc/include/asm/mmu.h:132,
                 from ./arch/powerpc/include/asm/lppaca.h:47,
                 from ./arch/powerpc/include/asm/paca.h:17,
                 from ./arch/powerpc/include/asm/current.h:13,
                 from ./include/linux/thread_info.h:21,
                 from ./arch/powerpc/include/asm/processor.h:39,
                 from ./include/linux/prefetch.h:15,
                 from drivers/net/ethernet/emulex/benet/be_main.c:14:
drivers/net/ethernet/emulex/benet/be_main.c: In function 'be_rx_cqs_create':
./include/asm-generic/getorder.h:54:9: warning: comparison is always
true due to limited range of data type [-Wtype-limits]
   (((n) < (1UL << PAGE_SHIFT)) ? 0 :  \
         ^
drivers/net/ethernet/emulex/benet/be_main.c:3138:33: note: in expansion
of macro 'get_order'
  adapter->big_page_size = (1 << get_order(rx_frag_size)) * PAGE_SIZE;
                                 ^~~~~~~~~

Fix it by moving all of this multi-line macro into a proper function,
and killing __get_order() off.

[akpm@linux-foundation.org: remove __get_order() altogether]
[cai@lca.pw: v2]
  Link: http://lkml.kernel.org/r/1564000166-31428-1-git-send-email-cai@lca.pw
Link: http://lkml.kernel.org/r/1563914986-26502-1-git-send-email-cai@lca.pw
Fixes: d66acc39c7ce ("bitops: Optimise get_order()")
Signed-off-by: Qian Cai 
Reviewed-by: Nathan Chancellor 
Cc: David S. Miller 
Cc: Arnd Bergmann 
Cc: David Howells 
Cc: Jakub Jelinek 
Cc: Nick Desaulniers 
Cc: Bill Wendling 
Cc: James Y Knight 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

sched/fair: Don't free p->numa_faults with concurrent readers

2019-11-22T15:57:07+00:00

commit 16d51a590a8ce3befb1308e0e7ab77f3b661af33 upstream.

When going through execve(), zero out the NUMA fault statistics instead of
freeing them.

During execve, the task is reachable through procfs and the scheduler. A
concurrent /proc/*/sched reader can read data from a freed ->numa_faults
allocation (confirmed by KASAN) and write it back to userspace.
I believe that it would also be possible for a use-after-free read to occur
through a race between a NUMA fault and execve(): task_numa_fault() can
lead to task_numa_compare(), which invokes task_weight() on the currently
running task of a different CPU.

Another way to fix this would be to make ->numa_faults RCU-managed or add
extra locking, but it seems easier to wipe the NUMA fault statistics on
execve.

Signed-off-by: Jann Horn 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Petr Mladek 
Cc: Sergey Senozhatsky 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Fixes: 82727018b0d3 ("sched/numa: Call task_numa_free() from do_execve()")
Link: https://lkml.kernel.org/r/20190716152047.14424-1-jannh@google.com
Signed-off-by: Ingo Molnar 
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings

ALSA: compress: Fix regression on compressed capture streams

2019-11-22T15:57:04+00:00

commit 4475f8c4ab7b248991a60d9c02808dbb813d6be8 upstream.

A previous fix to the stop handling on compressed capture streams causes
some knock on issues. The previous fix updated snd_compr_drain_notify to
set the state back to PREPARED for capture streams. This causes some
issues however as the handling for snd_compr_poll differs between the
two states and some user-space applications were relying on the poll
failing after the stream had been stopped.

To correct this regression whilst still fixing the original problem the
patch was addressing, update the capture handling to skip the PREPARED
state rather than skipping the SETUP state as it has done until now.

Fixes: 4f2ab5e1d13d ("ALSA: compress: Fix stop handling on compressed capture streams")
Signed-off-by: Charles Keepax 
Acked-by: Vinod Koul 
Signed-off-by: Takashi Iwai 
Signed-off-by: Ben Hutchings

x86/bugs: Add ITLB_MULTIHIT bug infrastructure

2019-11-15T00:56:52+00:00

commit db4d30fbb71b47e4ecb11c4efa5d8aad4b03dfae upstream.

Some processors may incur a machine check error possibly resulting in an
unrecoverable CPU lockup when an instruction fetch encounters a TLB
multi-hit in the instruction TLB. This can occur when the page size is
changed along with either the physical address or cache type. The relevant
erratum can be found here:

   https://bugzilla.kernel.org/show_bug.cgi?id=205195

There are other processors affected for which the erratum does not fully
disclose the impact.

This issue affects both bare-metal x86 page tables and EPT.

It can be mitigated by either eliminating the use of large pages or by
using careful TLB invalidations when changing the page size in the page
tables.

Just like Spectre, Meltdown, L1TF and MDS, a new bit has been allocated in
MSR_IA32_ARCH_CAPABILITIES (PSCHANGE_MC_NO) and will be set on CPUs which
are mitigated against this issue.

Signed-off-by: Vineela Tummalapalli 
Co-developed-by: Pawan Gupta 
Signed-off-by: Pawan Gupta 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Thomas Gleixner 
[bwh: Backported to 3.16:
 - Use next available X86_BUG bit
 - Don't use BIT() in msr-index.h because it's a UAPI header
 - No support for X86_VENDOR_HYGON, ATOM_AIRMONT_NP
 - Adjust filename, context, indentation]
Signed-off-by: Ben Hutchings

x86/speculation/taa: Add sysfs reporting for TSX Async Abort

2019-11-15T00:56:49+00:00

commit 6608b45ac5ecb56f9e171252229c39580cc85f0f upstream.

Add the sysfs reporting file for TSX Async Abort. It exposes the
vulnerability and the mitigation state similar to the existing files for
the other hardware vulnerabilities.

Sysfs file path is:
/sys/devices/system/cpu/vulnerabilities/tsx_async_abort

Signed-off-by: Pawan Gupta 
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Tested-by: Neelima Krishnan 
Reviewed-by: Mark Gross 
Reviewed-by: Tony Luck 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Josh Poimboeuf 
Signed-off-by: Ben Hutchings

VMCI: Fix integer overflow in VMCI handle arrays

2019-10-31T22:14:57+00:00

commit 1c2eb5b2853c9f513690ba6b71072d8eb65da16a upstream.

The VMCI handle array has an integer overflow in
vmci_handle_arr_append_entry when it tries to expand the array. This can be
triggered from a guest, since the doorbell link hypercall doesn't impose a
limit on the number of doorbell handles that a VM can create in the
hypervisor, and these handles are stored in a handle array.

In this change, we introduce a mandatory max capacity for handle
arrays/lists to avoid excessive memory usage.

Signed-off-by: Vishnu Dasa 
Reviewed-by: Adit Ranadive 
Reviewed-by: Jorgen Hansen 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

coredump: fix race condition between collapse_huge_page() and core dumping

2019-10-05T15:19:58+00:00

commit 59ea6d06cfa9247b586a695c21f94afa7183af74 upstream.

When fixing the race conditions between the coredump and the mmap_sem
holders outside the context of the process, we focused on
mmget_not_zero()/get_task_mm() callers in 04f5866e41fb70 ("coredump: fix
race condition between mmget_not_zero()/get_task_mm() and core
dumping"), but those aren't the only cases where the mmap_sem can be
taken outside of the context of the process as Michal Hocko noticed
while backporting that commit to older -stable kernels.

If mmgrab() is called in the context of the process, but then the
mm_count reference is transferred outside the context of the process,
that can also be a problem if the mmap_sem has to be taken for writing
through that mm_count reference.

khugepaged registration calls mmgrab() in the context of the process,
but the mmap_sem for writing is taken later in the context of the
khugepaged kernel thread.

collapse_huge_page() after taking the mmap_sem for writing doesn't
modify any vma, so it's not obvious that it could cause a problem to the
coredump, but it happens to modify the pmd in a way that breaks an
invariant that pmd_trans_huge_lock() relies upon.  collapse_huge_page()
needs the mmap_sem for writing just to block concurrent page faults that
call pmd_trans_huge_lock().

Specifically the invariant that "!pmd_trans_huge()" cannot become a
"pmd_trans_huge()" doesn't hold while collapse_huge_page() runs.

The coredump will call __get_user_pages() without mmap_sem for reading,
which eventually can invoke a lockless page fault which will need a
functional pmd_trans_huge_lock().

So collapse_huge_page() needs to use mmget_still_valid() to check it's
not running concurrently with the coredump...  as long as the coredump
can invoke page faults without holding the mmap_sem for reading.

This has "Fixes: khugepaged" to facilitate backporting, but in my view
it's more a bug in the coredump code that will eventually have to be
rewritten to stop invoking page faults without the mmap_sem for reading.
So the long term plan is still to drop all mmget_still_valid().

Link: http://lkml.kernel.org/r/20190607161558.32104-1-aarcange@redhat.com
Fixes: ba76149f47d8 ("thp: khugepaged")
Signed-off-by: Andrea Arcangeli 
Reported-by: Michal Hocko 
Acked-by: Michal Hocko 
Acked-by: Kirill A. Shutemov 
Cc: Oleg Nesterov 
Cc: Jann Horn 
Cc: Hugh Dickins 
Cc: Mike Rapoport 
Cc: Mike Kravetz 
Cc: Peter Xu 
Cc: Jason Gunthorpe 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
[bwh: Backported to 3.16:
 - Don't set result variable; collapse_huge_range() returns void
 - Adjust filenames]
Signed-off-by: Ben Hutchings