If we meet a conflicting object that is marked FSCACHE_OBJECT_IS_LIVE in
the active object tree, we have been emitting a BUG after logging
information about it and the new object.

Instead, we should wait for the CACHEFILES_OBJECT_ACTIVE flag to be cleared
on the old object (or return an error).  The ACTIVE flag should be cleared
after it has been removed from the active object tree.  A timeout of 60s is
used in the wait, so we shouldn't be able to get stuck there.

Fixes: 9ae326a6 ("CacheFiles: A cache that backs onto a mounted filesystem")
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>

In cachefiles_mark_object_active(), the new object is marked active and
then we try to add it to the active object tree.  If a conflicting object
is already present, we want to wait for that to go away.  After the wait,
we go round again and try to re-mark the object as being active - but it's
already marked active from the first time we went through and a BUG is
issued.

Fix this by clearing the CACHEFILES_OBJECT_ACTIVE flag before we try again.

Analysis from Kiran Kumar Modukuri:

[Impact]
Oops during heavy NFS + FSCache + Cachefiles

CacheFiles: Error: Overlong wait for old active object to go away.

BUG: unable to handle kernel NULL pointer dereference at 0000000000000002

CacheFiles: Error: Object already active kernel BUG at
fs/cachefiles/namei.c:163!

[Cause]
In a heavily loaded system with big files being read and truncated, an
fscache object for a cookie is being dropped and a new object being
looked. The new object being looked for has to wait for the old object
to go away before the new object is moved to active state.

[Fix]
Clear the flag 'CACHEFILES_OBJECT_ACTIVE' for the new object when
retrying the object lookup.

[Testcase]
Have run ~100 hours of NFS stress tests and have not seen this bug recur.

[Regression Potential]
 - Limited to fscache/cachefiles.

Fixes: 9ae326a6 ("CacheFiles: A cache that backs onto a mounted filesystem")
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>

When a cookie is allocated that causes fscache_object structs to be
allocated, those objects are initialised with the cookie pointer, but
aren't blessed with a ref on that cookie unless the attachment is
successfully completed in fscache_attach_object().

If attachment fails because the parent object was dying or there was a
collision, fscache_attach_object() returns without incrementing the cookie
counter - but upon failure of this function, the object is released which
then puts the cookie, whether or not a ref was taken on the cookie.

Fix this by taking a ref on the cookie when it is assigned in
fscache_object_init(), even when we're creating a root object.


Analysis from Kiran Kumar:

This bug has been seen in 4.4.0-124-generic #148-Ubuntu kernel

BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1776277

fscache cookie ref count updated incorrectly during fscache object
allocation resulting in following Oops.

kernel BUG at /build/linux-Y09MKI/linux-4.4.0/fs/fscache/internal.h:321!
kernel BUG at /build/linux-Y09MKI/linux-4.4.0/fs/fscache/cookie.c:639!

[Cause]
Two threads are trying to do operate on a cookie and two objects.

(1) One thread tries to unmount the filesystem and in process goes over a
    huge list of objects marking them dead and deleting the objects.
    cookie->usage is also decremented in following path:

      nfs_fscache_release_super_cookie
       -> __fscache_relinquish_cookie
        ->__fscache_cookie_put
        ->BUG_ON(atomic_read(&cookie->usage) <= 0);

(2) A second thread tries to lookup an object for reading data in following
    path:

    fscache_alloc_object
    1) cachefiles_alloc_object
        -> fscache_object_init
           -> assign cookie, but usage not bumped.
    2) fscache_attach_object -> fails in cant_attach_object because the
         cookie's backing object or cookie's->parent object are going away
    3) fscache_put_object
        -> cachefiles_put_object
          ->fscache_object_destroy
            ->fscache_cookie_put
               ->BUG_ON(atomic_read(&cookie->usage) <= 0);

[NOTE from dhowells] It's unclear as to the circumstances in which (2) can
take place, given that thread (1) is in nfs_kill_super(), however a
conflicting NFS mount with slightly different parameters that creates a
different superblock would do it.  A backtrace from Kiran seems to show
that this is a possibility:

    kernel BUG at/build/linux-Y09MKI/linux-4.4.0/fs/fscache/cookie.c:639!
    ...
    RIP: __fscache_cookie_put+0x3a/0x40 [fscache]
    Call Trace:
     __fscache_relinquish_cookie+0x87/0x120 [fscache]
     nfs_fscache_release_super_cookie+0x2d/0xb0 [nfs]
     nfs_kill_super+0x29/0x40 [nfs]
     deactivate_locked_super+0x48/0x80
     deactivate_super+0x5c/0x60
     cleanup_mnt+0x3f/0x90
     __cleanup_mnt+0x12/0x20
     task_work_run+0x86/0xb0
     exit_to_usermode_loop+0xc2/0xd0
     syscall_return_slowpath+0x4e/0x60
     int_ret_from_sys_call+0x25/0x9f

[Fix] Bump up the cookie usage in fscache_object_init, when it is first
being assigned a cookie atomically such that the cookie is added and bumped
up if its refcount is not zero.  Remove the assignment in
fscache_attach_object().

[Testcase]
I have run ~100 hours of NFS stress tests and not seen this bug recur.

[Regression Potential]
 - Limited to fscache/cachefiles.

Fixes: ccc4fc3d ("FS-Cache: Implement the cookie management part of the netfs API")
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>

cachefiles_read_waiter() has the right to access a 'monitor' object by
virtue of being called under the waitqueue lock for one of the pages in its
purview.  However, it has no ref on that monitor object or on the
associated operation.

What it is allowed to do is to move the monitor object to the operation's
to_do list, but once it drops the work_lock, it's actually no longer
permitted to access that object.  However, it is trying to enqueue the
retrieval operation for processing - but it can only do this via a pointer
in the monitor object, something it shouldn't be doing.

If it doesn't enqueue the operation, the operation may not get processed.
If the order is flipped so that the enqueue is first, then it's possible
for the work processor to look at the to_do list before the monitor is
enqueued upon it.

Fix this by getting a ref on the operation so that we can trust that it
will still be there once we've added the monitor to the to_do list and
dropped the work_lock.  The op can then be enqueued after the lock is
dropped.

The bug can manifest in one of a couple of ways.  The first manifestation
looks like:

 FS-Cache:
 FS-Cache: Assertion failed
 FS-Cache: 6 == 5 is false
 ------------[ cut here ]------------
 kernel BUG at fs/fscache/operation.c:494!
 RIP: 0010:fscache_put_operation+0x1e3/0x1f0
 ...
 fscache_op_work_func+0x26/0x50
 process_one_work+0x131/0x290
 worker_thread+0x45/0x360
 kthread+0xf8/0x130
 ? create_worker+0x190/0x190
 ? kthread_cancel_work_sync+0x10/0x10
 ret_from_fork+0x1f/0x30

This is due to the operation being in the DEAD state (6) rather than
INITIALISED, COMPLETE or CANCELLED (5) because it's already passed through
fscache_put_operation().

The bug can also manifest like the following:

 kernel BUG at fs/fscache/operation.c:69!
 ...
    [exception RIP: fscache_enqueue_operation+246]
 ...
 #7 [ffff883fff083c10] fscache_enqueue_operation at ffffffffa0b793c6
 #8 [ffff883fff083c28] cachefiles_read_waiter at ffffffffa0b15a48
 #9 [ffff883fff083c48] __wake_up_common at ffffffff810af028

I'm not entirely certain as to which is line 69 in Lei's kernel, so I'm not
entirely clear which assertion failed.

Fixes: 9ae326a6 ("CacheFiles: A cache that backs onto a mounted filesystem")
Reported-by: Lei Xue <carmark.dlut@gmail.com>
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Reported-by: Anthony DeRobertis <aderobertis@metrics.net>
Reported-by: NeilBrown <neilb@suse.com>
Reported-by: Daniel Axtens <dja@axtens.net>
Reported-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>

Alter the state-check assertion in fscache_enqueue_operation() to allow
cancelled operations to be given processing time so they can be cleaned up.

Also fix a debugging statement that was requiring such operations to have
an object assigned.

Fixes: 9ae326a6 ("CacheFiles: A cache that backs onto a mounted filesystem")
Reported-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>

If struct page is poisoned, and uninitialized access is detected via
PF_POISONED_CHECK(page) dump_page() is called to output the page.  But,
the dump_page() itself accesses struct page to determine how to print
it, and therefore gets into a recursive loop.

For example:

  dump_page()
   __dump_page()
    PageSlab(page)
     PF_POISONED_CHECK(page)
      VM_BUG_ON_PGFLAGS(PagePoisoned(page), page)
       dump_page() recursion loop.

Link: http://lkml.kernel.org/r/20180702180536.2552-1-pasha.tatashin@oracle.com
Fixes: f165b378 ("mm: uninitialized struct page poisoning sanity checking")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The ARM trusted foundations code is currently broken in linux-next when
CONFIG_KCOV_INSTRUMENT_ALL is set:

  /tmp/ccHdQsCI.s: Assembler messages:
  /tmp/ccHdQsCI.s:37: Error: .err encountered
  /tmp/ccHdQsCI.s:38: Error: .err encountered
  /tmp/ccHdQsCI.s:39: Error: .err encountered
  scripts/Makefile.build:311: recipe for target 'arch/arm/firmware/trusted_foundations.o' failed

I could not find a function attribute that lets me disable
-fsanitize-coverage=trace-pc for just one function, so this turns it off
for the entire file instead.

Link: http://lkml.kernel.org/r/20180529103636.1535457-1-arnd@arndb.de
Fixes: 75851720 ("arm: port KCOV to arm")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Olof Johansson <olof@lixom.net>
Tested-by: Olof Johansson <olof@lixom.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There is a special case that the size is "(N << KASAN_SHADOW_SCALE_SHIFT)
Pages plus X", the value of X is [1, KASAN_SHADOW_SCALE_SIZE-1].  The
operation "size >> KASAN_SHADOW_SCALE_SHIFT" will drop X, and the
roundup operation can not retrieve the missed one page.  For example:
size=0x28006, PAGE_SIZE=0x1000, KASAN_SHADOW_SCALE_SHIFT=3, we will get
shadow_size=0x5000, but actually we need 6 pages.

  shadow_size = round_up(size >> KASAN_SHADOW_SCALE_SHIFT, PAGE_SIZE);

This can lead to a kernel crash when kasan is enabled and the value of
mod->core_layout.size or mod->init_layout.size is like above.  Because
the shadow memory of X has not been allocated and mapped.

move_module:
  ptr = module_alloc(mod->core_layout.size);
  ...
  memset(ptr, 0, mod->core_layout.size);		//crashed

  Unable to handle kernel paging request at virtual address ffff0fffff97b000
  ......
  Call trace:
    __asan_storeN+0x174/0x1a8
    memset+0x24/0x48
    layout_and_allocate+0xcd8/0x1800
    load_module+0x190/0x23e8
    SyS_finit_module+0x148/0x180

Link: http://lkml.kernel.org/r/1529659626-12660-1-git-send-email-thunder.leizhen@huawei.comSigned-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Dmitriy Vyukov <dvyukov@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Libin <huawei.libin@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When booting with very large numbers of gigantic (i.e.  1G) pages, the
operations in the loop of gather_bootmem_prealloc, and specifically
prep_compound_gigantic_page, takes a very long time, and can cause a
softlockup if enough pages are requested at boot.

For example booting with 3844 1G pages requires prepping
(set_compound_head, init the count) over 1 billion 4K tail pages, which
takes considerable time.

Add a cond_resched() to the outer loop in gather_bootmem_prealloc() to
prevent this lockup.

Tested: Booted with softlockup_panic=1 hugepagesz=1G hugepages=3844 and
no softlockup is reported, and the hugepages are reported as
successfully setup.

Link: http://lkml.kernel.org/r/20180627214447.260804-1-cannonmatthews@google.comSigned-off-by: Cannon Matthews <cannonmatthews@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use huge_ptep_get() to translate huge ptes to normal ptes so we can
check them with the huge_pte_* functions.  Otherwise some architectures
will check the wrong values and will not wait for userspace to bring in
the memory.

Link: http://lkml.kernel.org/r/20180626132421.78084-1-frankja@linux.ibm.com
Fixes: 369cd212 ("userfaultfd: hugetlbfs: userfaultfd_huge_must_wait for hugepmd ranges")
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

My networking merge (commit 4e33d7d4: "Pull networking fixes from
David Miller") got the poll() handling conflict wrong for af_smc.

The conflict between my a11e1d43 ("Revert changes to convert to
->poll_mask() and aio IOCB_CMD_POLL") and Ursula Braun's 24ac3a08
("net/smc: rebuild nonblocking connect") should have left the call to
sock_poll_wait() in place, just without the socket lock release/retake.

And I really should have realized that.  But happily, I at least asked
Ursula to double-check the merge, and she set me right.

This also fixes an incidental whitespace issue nearby that annoyed me
while looking at this.
Pointed-out-by: Ursula Braun <ubraun@linux.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull MD fixes from Shaohua Li:
 "Two small fixes for MD:

   - an error handling fix from me

   - a recover bug fix for raid10 from BingJing"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md/raid10: fix that replacement cannot complete recovery after reassemble
  MD: cleanup resources in failure

Pull OpenRISC fixes from Stafford Horne:
 "Two fixes for issues which were breaking OpenRISC boot:

   - Fix bug in __pte_free_tlb() exposed in 4.18 by Matthew Wilcox's
     page table flag addition.

   - Fix issue booting on real hardware if delay slot detection
     emulation is disabled"

* tag 'for-linus' of git://github.com/stffrdhrn/linux:
  openrisc: entry: Fix delay slot exception detection
  openrisc: Call destructor during __pte_free_tlb

Pull networking fixes from David Miller:

 1) Verify netlink attributes properly in nf_queue, from Eric Dumazet.

 2) Need to bump memory lock rlimit for test_sockmap bpf test, from
    Yonghong Song.

 3) Fix VLAN handling in lan78xx driver, from Dave Stevenson.

 4) Fix uninitialized read in nf_log, from Jann Horn.

 5) Fix raw command length parsing in mlx5, from Alex Vesker.

 6) Cleanup loopback RDS connections upon netns deletion, from Sowmini
    Varadhan.

 7) Fix regressions in FIB rule matching during create, from Jason A.
    Donenfeld and Roopa Prabhu.

 8) Fix mpls ether type detection in nfp, from Pieter Jansen van Vuuren.

 9) More bpfilter build fixes/adjustments from Masahiro Yamada.

10) Fix XDP_{TX,REDIRECT} flushing in various drivers, from Jesper
    Dangaard Brouer.

11) fib_tests.sh file permissions were broken, from Shuah Khan.

12) Make sure BH/preemption is disabled in data path of mac80211, from
    Denis Kenzior.

13) Don't ignore nla_parse_nested() return values in nl80211, from
    Johannes berg.

14) Properly account sock objects ot kmemcg, from Shakeel Butt.

15) Adjustments to setting bpf program permissions to read-only, from
    Daniel Borkmann.

16) TCP Fast Open key endianness was broken, it always took on the host
    endiannness. Whoops. Explicitly make it little endian. From Yuching
    Cheng.

17) Fix prefix route setting for link local addresses in ipv6, from
    David Ahern.

18) Potential Spectre v1 in zatm driver, from Gustavo A. R. Silva.

19) Various bpf sockmap fixes, from John Fastabend.

20) Use after free for GRO with ESP, from Sabrina Dubroca.

21) Passing bogus flags to crypto_alloc_shash() in ipv6 SR code, from
    Eric Biggers.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (87 commits)
  qede: Adverstise software timestamp caps when PHC is not available.
  qed: Fix use of incorrect size in memcpy call.
  qed: Fix setting of incorrect eswitch mode.
  qed: Limit msix vectors in kdump kernel to the minimum required count.
  ipvlan: call dev_change_flags when ipvlan mode is reset
  ipv6: sr: fix passing wrong flags to crypto_alloc_shash()
  net: fix use-after-free in GRO with ESP
  tcp: prevent bogus FRTO undos with non-SACK flows
  bpf: sockhash, add release routine
  bpf: sockhash fix omitted bucket lock in sock_close
  bpf: sockmap, fix smap_list_map_remove when psock is in many maps
  bpf: sockmap, fix crash when ipv6 sock is added
  net: fib_rules: bring back rule_exists to match rule during add
  hv_netvsc: split sub-channel setup into async and sync
  net: use dev_change_tx_queue_len() for SIOCSIFTXQLEN
  atm: zatm: Fix potential Spectre v1
  s390/qeth: consistently re-enable device features
  s390/qeth: don't clobber buffer on async TX completion
  s390/qeth: avoid using is_multicast_ether_addr_64bits on (u8 *)[6]
  s390/qeth: fix race when setting MAC address
  ...

Sudarsana Reddy Kalluru says:

====================
qed*: Fix series.

The patch series addresses few issues in the qed* drivers.

Please consider applying it to 'net' branch.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

When ptp clock is not available for a PF (e.g., higher PFs in NPAR mode),
get-tsinfo() callback should return the software timestamp capabilities
instead of returning the error.

Fixes: 4c55215c ("qede: Add driver support for PTP")
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use the correct size value while copying chassis/port id values.

Fixes: 6ad8c632 ("qed: Add support for query/config dcbx.")
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

By default, driver sets the eswitch mode incorrectly as VEB (virtual
Ethernet bridging).
Need to set VEB eswitch mode only when sriov is enabled, and it should be
to set NONE by default. The patch incorporates this change.

Fixes: 0fefbfba ("qed*: Management firmware - notifications and defaults")
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Memory size is limited in the kdump kernel environment. Allocation of more
msix-vectors (or queues) consumes few tens of MBs of memory, which might
lead to the kdump kernel failure.
This patch adds changes to limit the number of MSI-X vectors in kdump
kernel to minimum required value (i.e., 2 per engine).

Fixes: fe56b9e6 ("qed: Add module with basic common support")
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

After we change the ipvlan mode from l3 to l2, or vice versa, we only
reset IFF_NOARP flag, but don't flush the ARP table cache, which will
cause eth->h_dest to be equal to eth->h_source in ipvlan_xmit_mode_l2().
Then the message will not come out of host.

Here is the reproducer on local host:

ip link set eth1 up
ip addr add 192.168.1.1/24 dev eth1
ip link add link eth1 ipvlan1 type ipvlan mode l3

ip netns add net1
ip link set ipvlan1 netns net1
ip netns exec net1 ip link set ipvlan1 up
ip netns exec net1 ip addr add 192.168.2.1/24 dev ipvlan1

ip route add 192.168.2.0/24 via 192.168.1.2
ping 192.168.2.2 -c 2

ip netns exec net1 ip link set ipvlan1 type ipvlan mode l2
ping 192.168.2.2 -c 2

Add the same configuration on remote host. After we set the mode to l2,
we could find that the src/dst MAC addresses are the same on eth1:

21:26:06.648565 00:b7:13:ad:d3:05 > 00:b7:13:ad:d3:05, ethertype IPv4 (0x0800), length 98: (tos 0x0, ttl 64, id 58356, offset 0, flags [DF], proto ICMP (1), length 84)
    192.168.2.1 > 192.168.2.2: ICMP echo request, id 22686, seq 1, length 64

Fix this by calling dev_change_flags(), which will call netdevice notifier
with flag change info.

v2:
a) As pointed out by Wang Cong, check return value for dev_change_flags() when
change dev flags.
b) As suggested by Stefano and Sabrina, move flags setting before l3mdev_ops.
So we don't need to redo ipvlan_{, un}register_nf_hook() again in err path.
Reported-by: Jianlin Shi <jishi@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Fixes: 2ad7bf36 ("ipvlan: Initial check-in of the IPVLAN driver.")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The 'mask' argument to crypto_alloc_shash() uses the CRYPTO_ALG_* flags,
not 'gfp_t'.  So don't pass GFP_KERNEL to it.

Fixes: bf355b8d ("ipv6: sr: add core files for SR HMAC support")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since the addition of GRO for ESP, gro_receive can consume the skb and
return -EINPROGRESS. In that case, the lower layer GRO handler cannot
touch the skb anymore.

Commit 5f114163 ("net: Add a skb_gro_flush_final helper.") converted
some of the gro_receive handlers that can lead to ESP's gro_receive so
that they wouldn't access the skb when -EINPROGRESS is returned, but
missed other spots, mainly in tunneling protocols.

This patch finishes the conversion to using skb_gro_flush_final(), and
adds a new helper, skb_gro_flush_final_remcsum(), used in VXLAN and
GUE.

Fixes: 5f114163 ("net: Add a skb_gro_flush_final helper.")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull btrfs fixes from David Sterba:
 "We have a few regression fixes for qgroup rescan status tracking and
  the vm_fault_t conversion that mixed up the error values"

* tag 'for-4.18-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix mount failure when qgroup rescan is in progress
  Btrfs: fix regression in btrfs_page_mkwrite() from vm_fault_t conversion
  btrfs: quota: Set rescan progress to (u64)-1 if we hit last leaf

Pull vfs fix from Al Viro:
 "Followup to procfs-seq_file series this window"

This fixes a memory leak by making sure that proc seq files release any
private data on close.  The 'proc_seq_open' has to be properly paired
with 'proc_seq_release' that releases the extra private data.

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  proc: add proc_seq_release

Pull staging/IIO fixes from Greg KH:
 "Here are a few small staging and IIO driver fixes for 4.18-rc3.

  Nothing major or big, all just fixes for reported problems since
  4.18-rc1. All of these have been in linux-next this week with no
  reported problems"

* tag 'staging-4.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: android: ion: Return an ERR_PTR in ion_map_kernel
  staging: comedi: quatech_daqp_cs: fix no-op loop daqp_ao_insn_write()
  iio: imu: inv_mpu6050: Fix probe() failure on older ACPI based machines
  iio: buffer: fix the function signature to match implementation
  iio: mma8452: Fix ignoring MMA8452_INT_DRDY
  iio: tsl2x7x/tsl2772: avoid potential division by zero
  iio: pressure: bmp280: fix relative humidity unit

Pull tty/serial fixes from Greg KH:
 "Here are five fixes for the tty core and some serial drivers.

  The tty core ones fix some security and other issues reported by the
  syzbot that I have taken too long in responding to (sorry Tetsuo!).

  The 8350 serial driver fix resolves an issue of devices that used to
  work properly stopping working as they shouldn't have been added to a
  blacklist.

  All of these have been in linux-next for a few days with no reported
  issues"

* tag 'tty-4.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  vt: prevent leaking uninitialized data to userspace via /dev/vcs*
  serdev: fix memleak on module unload
  serial: 8250_pci: Remove stalled entries in blacklist
  n_tty: Access echo_* variables carefully.
  n_tty: Fix stall at n_tty_receive_char_special().

Pull USB fixes from Greg KH:
 "Here is a number of USB gadget and other driver fixes for 4.18-rc3.

  There's a bunch of them here, most of them being gadget driver and
  xhci host controller fixes for reported issues (as normal), but there
  are also some new device ids, and some fixes for the typec code.

  There is an acpi core patch in here that was acked by the acpi
  maintainer as it is needed for the typec fixes in order to properly
  solve a problem in that driver.

  All of these have been in linux-next this week with no reported
  issues"

* tag 'usb-4.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (33 commits)
  usb: chipidea: host: fix disconnection detect issue
  usb: typec: tcpm: fix logbuffer index is wrong if _tcpm_log is re-entered
  typec: tcpm: Fix a msecs vs jiffies bug
  NFC: pn533: Fix wrong GFP flag usage
  usb: cdc_acm: Add quirk for Uniden UBC125 scanner
  staging/typec: fix tcpci_rt1711h build errors
  usb: typec: ucsi: Fix for incorrect status data issue
  usb: typec: ucsi: acpi: Workaround for cache mode issue
  acpi: Add helper for deactivating memory region
  usb: xhci: increase CRS timeout value
  usb: xhci: tegra: fix runtime PM error handling
  usb: xhci: remove the code build warning
  xhci: Fix kernel oops in trace_xhci_free_virt_device
  xhci: Fix perceived dead host due to runtime suspend race with event handler
  dwc2: gadget: Fix ISOC IN DDMA PID bitfield value calculation
  usb: gadget: dwc2: fix memory leak in gadget_init()
  usb: gadget: composite: fix delayed_status race condition when set_interface
  usb: dwc2: fix isoc split in transfer with no data
  usb: dwc2: alloc dma aligned buffer for isoc split in
  usb: dwc2: fix the incorrect bitmaps for the ports of multi_tt hub
  ...

Pull dma mapping fixlet from Christoph Hellwig:
 "Add a missing export required by riscv and unicore"

* tag 'dma-mapping-4.18-2' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: export swiotlb_dma_ops

If SACK is not enabled and the first cumulative ACK after the RTO
retransmission covers more than the retransmitted skb, a spurious
FRTO undo will trigger (assuming FRTO is enabled for that RTO).
The reason is that any non-retransmitted segment acknowledged will
set FLAG_ORIG_SACK_ACKED in tcp_clean_rtx_queue even if there is
no indication that it would have been delivered for real (the
scoreboard is not kept with TCPCB_SACKED_ACKED bits in the non-SACK
case so the check for that bit won't help like it does with SACK).
Having FLAG_ORIG_SACK_ACKED set results in the spurious FRTO undo
in tcp_process_loss.

We need to use more strict condition for non-SACK case and check
that none of the cumulatively ACKed segments were retransmitted
to prove that progress is due to original transmissions. Only then
keep FLAG_ORIG_SACK_ACKED set, allowing FRTO undo to proceed in
non-SACK case.

(FLAG_ORIG_SACK_ACKED is planned to be renamed to FLAG_ORIG_PROGRESS
to better indicate its purpose but to keep this change minimal, it
will be done in another patch).

Besides burstiness and congestion control violations, this problem
can result in RTO loop: When the loss recovery is prematurely
undoed, only new data will be transmitted (if available) and
the next retransmission can occur only after a new RTO which in case
of multiple losses (that are not for consecutive packets) requires
one RTO per loss to recover.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Tested-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Originally in patch e6d20c55 ("openrisc: entry: Fix delay slot
detection") I fixed delay slot detection, but only for QEMU.  We missed
that hardware delay slot detection using delay slot exception flag (DSX)
was still broken.  This was because QEMU set the DSX flag in both
pre-exception supervision register (ESR) and supervision register (SR)
register, but on real hardware the DSX flag is only set on the SR
register during exceptions.

Fix this by carrying the DSX flag into the SR register during exception.
We also update the DSX flag read locations to read the value from the SR
register not the pt_regs SR register which represents ESR.  The ESR
should never have the DSX flag set.

In the process I updated/removed a few comments to match the current
state.  Including removing a comment saying that the DSX detection logic
was inefficient and needed to be rewritten.

I have tested this on QEMU with a patch ensuring it matches the hardware
specification.

Link: https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg00000.html
Fixes: e6d20c55 ("openrisc: entry: Fix delay slot detection")
Signed-off-by: Stafford Horne <shorne@gmail.com>

Daniel Borkmann says:

====================
pull-request: bpf 2018-07-01

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) A bpf_fib_lookup() helper fix to change the API before freeze to
   return an encoding of the FIB lookup result and return the nexthop
   device index in the params struct (instead of device index as return
   code that we had before), from David.

2) Various BPF JIT fixes to address syzkaller fallout, that is, do not
   reject progs when set_memory_*() fails since it could still be RO.
   Also arm32 JIT was not using bpf_jit_binary_lock_ro() API which was
   an issue, and a memory leak in s390 JIT found during review, from
   Daniel.

3) Multiple fixes for sockmap/hash to address most of the syzkaller
   triggered bugs. Usage with IPv6 was crashing, a GPF in bpf_tcp_close(),
   a missing sock_map_release() routine to hook up to callbacks, and a
   fix for an omitted bucket lock in sock_close(), from John.

4) Two bpftool fixes to remove duplicated error message on program load,
   and another one to close the libbpf object after program load. One
   additional fix for nfp driver's BPF offload to avoid stopping offload
   completely if replace of program failed, from Jakub.

5) Couple of BPF selftest fixes that bail out in some of the test
   scripts if the user does not have the right privileges, from Jeffrin.

6) Fixes in test_bpf for s390 when CONFIG_BPF_JIT_ALWAYS_ON is set
   where we need to set the flag that some of the test cases are expected
   to fail, from Kleber.

7) Fix to detangle BPF_LIRC_MODE2 dependency from CONFIG_CGROUP_BPF
   since it has no relation to it and lirc2 users often have configs
   without cgroups enabled and thus would not be able to use it, from Sean.

8) Fix a selftest failure in sockmap by removing a useless setrlimit()
   call that would set a too low limit where at the same time we are
   already including bpf_rlimit.h that does the job, from Yonghong.

9) Fix BPF selftest config with missing missing NET_SCHED, from Anders.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

John Fastabend says:

====================
This addresses two syzbot issues that lead to identifying (by Eric and
Wei) a class of bugs where we don't correctly check for IPv4/v6
sockets and their associated state. The second issue was a locking
omission in sockhash.

The first patch addresses IPv6 socks and fixing an error where
sockhash would overwrite the prot pointer with IPv4 prot. To fix
this build similar solution to TLS ULP. Although we continue to
allow socks in all states not just ESTABLISH in this patch set
because as Martin points out there should be no issue with this
on the sockmap ULP because we don't use the ctx in this code. Once
multiple ULPs coexist we may need to revisit this. However we
can do this in *next trees.

The other issue syzbot found that the tcp_close() handler missed
locking the hash bucket lock which could result in corrupting the
sockhash bucket list if delete and close ran at the same time.
And also the smap_list_remove() routine was not working correctly
at all. This was not caught in my testing because in general my
tests (to date at least lets add some more robust selftest in
bpf-next) do things in the "expected" order, create map, add socks,
delete socks, then tear down maps. The tests we have that do the
ops out of this order where only working on single maps not multi-
maps so we never saw the issue. Thanks syzbot. The fix is to
restructure the tcp_close() lock handling. And fix the obvious
bug in smap_list_remove().

Finally, during review I noticed the release handler was omitted
from the upstream code (patch 4) due to an incorrect merge conflict
fix when I ported the code to latest bpf-next before submitting.
This would leave references to the map around if the user never
closes the map.

v3: rework patches, dropping ESTABLISH check and adding rcu
    annotation along with the smap_list_remove fix

v4: missed one more case where maps was being accessed without
    the sk_callback_lock, spoted by Martin as well.

v5: changed to use a specific lock for maps and reduced callback
    lock so that it is only used to gaurd sk callbacks. I think
    this makes the logic a bit cleaner and avoids confusion
    ovoer what each lock is doing.

Also big thanks to Martin for thorough review he caught at least
one case where I missed a rcu_call().
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Add map_release_uref pointer to hashmap ops. This was dropped when
original sockhash code was ported into bpf-next before initial
commit.

Fixes: 81110384 ("bpf: sockmap, add hash map support")
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

First the sk_callback_lock() was being used to protect both the
sock callback hooks and the psock->maps list. This got overly
convoluted after the addition of sockhash (in sockmap it made
some sense because masp and callbacks were tightly coupled) so
lets split out a specific lock for maps and only use the callback
lock for its intended purpose. This fixes a couple cases where
we missed using maps lock when it was in fact needed. Also this
makes it easier to follow the code because now we can put the
locking closer to the actual code its serializing.

Next, in sock_hash_delete_elem() the pattern was as follows,

  sock_hash_delete_elem()
     [...]
     spin_lock(bucket_lock)
     l = lookup_elem_raw()
     if (l)
        hlist_del_rcu()
        write_lock(sk_callback_lock)
         .... destroy psock ...
        write_unlock(sk_callback_lock)
     spin_unlock(bucket_lock)

The ordering is necessary because we only know the {p}sock after
dereferencing the hash table which we can't do unless we have the
bucket lock held. Once we have the bucket lock and the psock element
it is deleted from the hashmap to ensure any other path doing a lookup
will fail. Finally, the refcnt is decremented and if zero the psock
is destroyed.

In parallel with the above (or free'ing the map) a tcp close event
may trigger tcp_close(). Which at the moment omits the bucket lock
altogether (oops!) where the flow looks like this,

  bpf_tcp_close()
     [...]
     write_lock(sk_callback_lock)
     for each psock->maps // list of maps this sock is part of
         hlist_del_rcu(ref_hash_node);
         .... destroy psock ...
     write_unlock(sk_callback_lock)

Obviously, and demonstrated by syzbot, this is broken because
we can have multiple threads deleting entries via hlist_del_rcu().

To fix this we might be tempted to wrap the hlist operation in a
bucket lock but that would create a lock inversion problem. In
summary to follow locking rules the psocks maps list needs the
sk_callback_lock (after this patch maps_lock) but we need the bucket
lock to do the hlist_del_rcu.

To resolve the lock inversion problem pop the head of the maps list
repeatedly and remove the reference until no more are left. If a
delete happens in parallel from the BPF API that is OK as well because
it will do a similar action, lookup the lock in the map/hash, delete
it from the map/hash, and dec the refcnt. We check for this case
before doing a destroy on the psock to ensure we don't have two
threads tearing down a psock. The new logic is as follows,

  bpf_tcp_close()
  e = psock_map_pop(psock->maps) // done with map lock
  bucket_lock() // lock hash list bucket
  l = lookup_elem_raw(head, hash, key, key_size);
  if (l) {
     //only get here if elmnt was not already removed
     hlist_del_rcu()
     ... destroy psock...
  }
  bucket_unlock()

And finally for all the above to work add missing locking around  map
operations per above. Then add RCU annotations and use
rcu_dereference/rcu_assign_pointer to manage values relying on RCU so
that the object is not free'd from sock_hash_free() while it is being
referenced in bpf_tcp_close().

Reported-by: syzbot+0ce137753c78f7b6acc1@syzkaller.appspotmail.com
Fixes: 81110384 ("bpf: sockmap, add hash map support")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

If a hashmap is free'd with open socks it removes the reference to
the hash entry from the psock. If that is the last reference to the
psock then it will also be free'd by the reference counting logic.
However the current logic that removes the hash reference from the
list of references is broken. In smap_list_remove() we first check
if the sockmap entry matches and then check if the hashmap entry
matches. But, the sockmap entry sill always match because its NULL in
this case which causes the first entry to be removed from the list.
If this is always the "right" entry (because the user adds/removes
entries in order) then everything is OK but otherwise a subsequent
bpf_tcp_close() may reference a free'd object.

To fix this create two list handlers one for sockmap and one for
sockhash.

Reported-by: syzbot+0ce137753c78f7b6acc1@syzkaller.appspotmail.com
Fixes: 81110384 ("bpf: sockmap, add hash map support")
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

This fixes a crash where we assign tcp_prot to IPv6 sockets instead
of tcpv6_prot.

Previously we overwrote the sk->prot field with tcp_prot even in the
AF_INET6 case. This patch ensures the correct tcp_prot and tcpv6_prot
are used.

Tested with 'netserver -6' and 'netperf -H [IPv6]' as well as
'netperf -H [IPv4]'. The ESTABLISHED check resolves the previously
crashing case here.

Fixes: 174a79ff ("bpf: sockmap with sk redirect support")
Reported-by: syzbot+5c063698bdbfac19f363@syzkaller.appspotmail.com
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Pull parisc fixes and cleanups from Helge Deller:
 "Nothing exiting in this patchset, just

   - small cleanups of header files

   - default to 4 CPUs when building a SMP kernel

   - mark 16kB and 64kB page sizes broken

   - addition of the new io_pgetevents syscall"

* 'parisc-4.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Build kernel without -ffunction-sections
  parisc: Reduce debug output in unwind code
  parisc: Wire up io_pgetevents syscall
  parisc: Default to 4 SMP CPUs
  parisc: Convert printk(KERN_LEVEL) to pr_lvl()
  parisc: Mark 16kB and 64kB page sizes BROKEN
  parisc: Drop struct sigaction from not exported header file

Pull ARM SoC fixes from Olof Johansson:
 "A smaller batch for the end of the week (let's see if I can keep the
  weekly cadence going for once).

  All medium-grade fixes here, nothing worrisome:

   - Fixes for some fairly old bugs around SD card write-protect
     detection and GPIO interrupt assignments on Davinci.

   - Wifi module suspend fix for Hikey.

   - Minor DT tweaks to fix inaccuracies for Amlogic platforms, one
     of which solves booting with third-party u-boot"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  arm64: dts: hikey960: Define wl1837 power capabilities
  arm64: dts: hikey: Define wl1835 power capabilities
  ARM64: dts: meson-gxl: fix Mali GPU compatible string
  ARM64: dts: meson-axg: fix ethernet stability issue
  ARM64: dts: meson-gx: fix ATF reserved memory region
  ARM64: dts: meson-gxl-s905x-p212: Add phy-supply for usb0
  ARM64: dts: meson: fix register ranges for SD/eMMC
  ARM64: dts: meson: disable sd-uhs modes on the libretech-cc
  ARM: dts: da850: Fix interrups property for gpio
  ARM: davinci: board-da850-evm: fix WP pin polarity for MMC/SD

Merge tag 'kbuild-fixes-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - introduce __diag_* macros and suppress -Wattribute-alias warnings
   from GCC 8

 - fix stack protector test script for x86_64

 - fix line number handling in Kconfig

 - document that '#' starts a comment in Kconfig

 - handle P_SYMBOL property in dump debugging of Kconfig

 - correct help message of LD_DEAD_CODE_DATA_ELIMINATION

 - fix occasional segmentation faults in Kconfig

* tag 'kbuild-fixes-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: loop boundary condition fix
  kbuild: reword help of LD_DEAD_CODE_DATA_ELIMINATION
  kconfig: handle P_SYMBOL in print_symbol()
  kconfig: document Kconfig source file comments
  kconfig: fix line numbers for if-entries in menu tree
  stack-protector: Fix test with 32-bit userland and CONFIG_64BIT=y
  powerpc: Remove -Wattribute-alias pragmas
  disable -Wattribute-alias warning for SYSCALL_DEFINEx()
  kbuild: add macro for controlling warnings to linux/compiler.h