[ Upstream commit 13fc1d27 ]

There is a race between setting up a qgroup rescan worker and completing
a qgroup rescan worker that can lead to callers of the qgroup rescan wait
ioctl to either not wait for the rescan worker to complete or to hang
forever due to missing wake ups. The following diagram shows a sequence
of steps that illustrates the race.

        CPU 1                                                         CPU 2                                  CPU 3

 btrfs_ioctl_quota_rescan()
  btrfs_qgroup_rescan()
   qgroup_rescan_init()
    mutex_lock(&fs_info->qgroup_rescan_lock)
    spin_lock(&fs_info->qgroup_lock)

    fs_info->qgroup_flags |=
      BTRFS_QGROUP_STATUS_FLAG_RESCAN

    init_completion(
      &fs_info->qgroup_rescan_completion)

    fs_info->qgroup_rescan_running = true

    mutex_unlock(&fs_info->qgroup_rescan_lock)
    spin_unlock(&fs_info->qgroup_lock)

    btrfs_init_work()
     --> starts the worker

                                                        btrfs_qgroup_rescan_worker()
                                                         mutex_lock(&fs_info->qgroup_rescan_lock)

                                                         fs_info->qgroup_flags &=
                                                           ~BTRFS_QGROUP_STATUS_FLAG_RESCAN

                                                         mutex_unlock(&fs_info->qgroup_rescan_lock)

                                                         starts transaction, updates qgroup status
                                                         item, etc

                                                                                                           btrfs_ioctl_quota_rescan()
                                                                                                            btrfs_qgroup_rescan()
                                                                                                             qgroup_rescan_init()
                                                                                                              mutex_lock(&fs_info->qgroup_rescan_lock)
                                                                                                              spin_lock(&fs_info->qgroup_lock)

                                                                                                              fs_info->qgroup_flags |=
                                                                                                                BTRFS_QGROUP_STATUS_FLAG_RESCAN

                                                                                                              init_completion(
                                                                                                                &fs_info->qgroup_rescan_completion)

                                                                                                              fs_info->qgroup_rescan_running = true

                                                                                                              mutex_unlock(&fs_info->qgroup_rescan_lock)
                                                                                                              spin_unlock(&fs_info->qgroup_lock)

                                                                                                              btrfs_init_work()
                                                                                                               --> starts another worker

                                                         mutex_lock(&fs_info->qgroup_rescan_lock)

                                                         fs_info->qgroup_rescan_running = false

                                                         mutex_unlock(&fs_info->qgroup_rescan_lock)

							 complete_all(&fs_info->qgroup_rescan_completion)

Before the rescan worker started by the task at CPU 3 completes, if
another task calls btrfs_ioctl_quota_rescan(), it will get -EINPROGRESS
because the flag BTRFS_QGROUP_STATUS_FLAG_RESCAN is set at
fs_info->qgroup_flags, which is expected and correct behaviour.

However if other task calls btrfs_ioctl_quota_rescan_wait() before the
rescan worker started by the task at CPU 3 completes, it will return
immediately without waiting for the new rescan worker to complete,
because fs_info->qgroup_rescan_running is set to false by CPU 2.

This race is making test case btrfs/171 (from fstests) to fail often:

  btrfs/171 9s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad)
#      --- tests/btrfs/171.out     2018-09-16 21:30:48.505104287 +0100
#      +++ /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad      2019-09-19 02:01:36.938486039 +0100
#      @@ -1,2 +1,3 @@
#       QA output created by 171
#      +ERROR: quota rescan failed: Operation now in progress
#       Silence is golden
#      ...
#      (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/171.out /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad'  to see the entire diff)

That is because the test calls the btrfs-progs commands "qgroup quota
rescan -w", "qgroup assign" and "qgroup remove" in a sequence that makes
calls to the rescan start ioctl fail with -EINPROGRESS (note the "btrfs"
commands 'qgroup assign' and 'qgroup remove' often call the rescan start
ioctl after calling the qgroup assign ioctl,
btrfs_ioctl_qgroup_assign()), since previous waits didn't actually wait
for a rescan worker to complete.

Another problem the race can cause is missing wake ups for waiters,
since the call to complete_all() happens outside a critical section and
after clearing the flag BTRFS_QGROUP_STATUS_FLAG_RESCAN. In the sequence
diagram above, if we have a waiter for the first rescan task (executed
by CPU 2), then fs_info->qgroup_rescan_completion.wait is not empty, and
if after the rescan worker clears BTRFS_QGROUP_STATUS_FLAG_RESCAN and
before it calls complete_all() against
fs_info->qgroup_rescan_completion, the task at CPU 3 calls
init_completion() against fs_info->qgroup_rescan_completion which
re-initilizes its wait queue to an empty queue, therefore causing the
rescan worker at CPU 2 to call complete_all() against an empty queue,
never waking up the task waiting for that rescan worker.

Fix this by clearing BTRFS_QGROUP_STATUS_FLAG_RESCAN and setting
fs_info->qgroup_rescan_running to false in the same critical section,
delimited by the mutex fs_info->qgroup_rescan_lock, as well as doing the
call to complete_all() in that same critical section. This gives the
protection needed to avoid rescan wait ioctl callers not waiting for a
running rescan worker and the lost wake ups problem, since setting that
rescan flag and boolean as well as initializing the wait queue is done
already in a critical section delimited by that mutex (at
qgroup_rescan_init()).

Fixes: 57254b6e ("Btrfs: add ioctl to wait for qgroup rescan completion")
Fixes: d2c609b8

 ("btrfs: properly track when rescan worker is running")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 6af112b1 upstream.

When doing any form of incremental send the parent and the child trees
need to be compared via btrfs_compare_trees. This  can result in long
loop chains without ever relinquishing the CPU. This causes softlockup
detector to trigger when comparing trees with a lot of items. Example
report:

watchdog: BUG: soft lockup - CPU#0 stuck for 24s! [snapperd:16153]
CPU: 0 PID: 16153 Comm: snapperd Not tainted 5.2.9-1-default #1 openSUSE Tumbleweed (unreleased)
Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
pstate: 40000005 (nZcv daif -PAN -UAO)
pc : __ll_sc_arch_atomic_sub_return+0x14/0x20
lr : btrfs_release_extent_buffer_pages+0xe0/0x1e8 [btrfs]
sp : ffff00001273b7e0
Call trace:
 __ll_sc_arch_atomic_sub_return+0x14/0x20
 release_extent_buffer+0xdc/0x120 [btrfs]
 free_extent_buffer.part.0+0xb0/0x118 [btrfs]
 free_extent_buffer+0x24/0x30 [btrfs]
 btrfs_release_path+0x4c/0xa0 [btrfs]
 btrfs_free_path.part.0+0x20/0x40 [btrfs]
 btrfs_free_path+0x24/0x30 [btrfs]
 get_inode_info+0xa8/0xf8 [btrfs]
 finish_inode_if_needed+0xe0/0x6d8 [btrfs]
 changed_cb+0x9c/0x410 [btrfs]
 btrfs_compare_trees+0x284/0x648 [btrfs]
 send_subvol+0x33c/0x520 [btrfs]
 btrfs_ioctl_send+0x8a0/0xaf0 [btrfs]
 btrfs_ioctl+0x199c/0x2288 [btrfs]
 do_vfs_ioctl+0x4b0/0x820
 ksys_ioctl+0x84/0xb8
 __arm64_sys_ioctl+0x28/0x38
 el0_svc_common.constprop.0+0x7c/0x188
 el0_svc_handler+0x34/0x90
 el0_svc+0x8/0xc

Fix this by adding a call to cond_resched at the beginning of the main
loop in btrfs_compare_trees.

Fixes: 7069830a

 ("Btrfs: add btrfs_compare_trees function")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit efad8a85 upstream.

At ctree.c:get_old_root(), we are accessing a root's header owner field
after we have freed the respective extent buffer. This results in an
use-after-free that can lead to crashes, and when CONFIG_DEBUG_PAGEALLOC
is set, results in a stack trace like the following:

  [ 3876.799331] stack segment: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
  [ 3876.799363] CPU: 0 PID: 15436 Comm: pool Not tainted 5.3.0-rc3-btrfs-next-54 #1
  [ 3876.799385] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
  [ 3876.799433] RIP: 0010:btrfs_search_old_slot+0x652/0xd80 [btrfs]
  (...)
  [ 3876.799502] RSP: 0018:ffff9f08c1a2f9f0 EFLAGS: 00010286
  [ 3876.799518] RAX: ffff8dd300000000 RBX: ffff8dd85a7a9348 RCX: 000000038da26000
  [ 3876.799538] RDX: 0000000000000000 RSI: ffffe522ce368980 RDI: 0000000000000246
  [ 3876.799559] RBP: dae1922adadad000 R08: 0000000008020000 R09: ffffe522c0000000
  [ 3876.799579] R10: ffff8dd57fd788c8 R11: 000000007511b030 R12: ffff8dd781ddc000
  [ 3876.799599] R13: ffff8dd9e6240578 R14: ffff8dd6896f7a88 R15: ffff8dd688cf90b8
  [ 3876.799620] FS:  00007f23ddd97700(0000) GS:ffff8dda20200000(0000) knlGS:0000000000000000
  [ 3876.799643] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 3876.799660] CR2: 00007f23d4024000 CR3: 0000000710bb0005 CR4: 00000000003606f0
  [ 3876.799682] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [ 3876.799703] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [ 3876.799723] Call Trace:
  [ 3876.799735]  ? do_raw_spin_unlock+0x49/0xc0
  [ 3876.799749]  ? _raw_spin_unlock+0x24/0x30
  [ 3876.799779]  resolve_indirect_refs+0x1eb/0xc80 [btrfs]
  [ 3876.799810]  find_parent_nodes+0x38d/0x1180 [btrfs]
  [ 3876.799841]  btrfs_check_shared+0x11a/0x1d0 [btrfs]
  [ 3876.799870]  ? extent_fiemap+0x598/0x6e0 [btrfs]
  [ 3876.799895]  extent_fiemap+0x598/0x6e0 [btrfs]
  [ 3876.799913]  do_vfs_ioctl+0x45a/0x700
  [ 3876.799926]  ksys_ioctl+0x70/0x80
  [ 3876.799938]  ? trace_hardirqs_off_thunk+0x1a/0x20
  [ 3876.799953]  __x64_sys_ioctl+0x16/0x20
  [ 3876.799965]  do_syscall_64+0x62/0x220
  [ 3876.799977]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [ 3876.799993] RIP: 0033:0x7f23e0013dd7
  (...)
  [ 3876.800056] RSP: 002b:00007f23ddd96ca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  [ 3876.800078] RAX: ffffffffffffffda RBX: 00007f23d80210f8 RCX: 00007f23e0013dd7
  [ 3876.800099] RDX: 00007f23d80210f8 RSI: 00000000c020660b RDI: 0000000000000003
  [ 3876.800626] RBP: 000055fa2a2a2440 R08: 0000000000000000 R09: 00007f23ddd96d7c
  [ 3876.801143] R10: 00007f23d8022000 R11: 0000000000000246 R12: 00007f23ddd96d80
  [ 3876.801662] R13: 00007f23ddd96d78 R14: 00007f23d80210f0 R15: 00007f23ddd96d80
  (...)
  [ 3876.805107] ---[ end trace e53161e179ef04f9 ]---

Fix that by saving the root's header owner field into a local variable
before freeing the root's extent buffer, and then use that local variable
when needed.

Fixes: 30b0463a

 ("Btrfs: fix accessing the root pointer in tree mod log functions")
CC: stable@vger.kernel.org # 3.10+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 5c2e9f34

 upstream.

When filtering xattr list for reading, presence of trusted xattr
results in a security audit log.  However, if there is other content
no errno will be set, and if there isn't, the errno will be -ENODATA
and not -EPERM as is usually associated with a lack of capability.
The check does not block the request to list the xattrs present.

Switch to ns_capable_noaudit to reflect a more appropriate check.

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Cc: linux-security-module@vger.kernel.org
Cc: kernel-team@android.com
Cc: stable@vger.kernel.org # v3.18+
Fixes: a082c6f6

 ("ovl: filter trusted xattr for non-admin")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a016e279

 upstream.

There may be situations when a server negotiates SMB 2.1
protocol version or higher but responds to a CREATE request
with an oplock rather than a lease.

Currently the client doesn't handle such a case correctly:
when another CREATE comes in the server sends an oplock
break to the initial CREATE and the client doesn't send
an ack back due to a wrong caching level being set (READ
instead of RWH). Missing an oplock break ack makes the
server wait until the break times out which dramatically
increases the latency of the second CREATE.

Fix this by properly detecting oplocks when using SMB 2.1
protocol version and higher.

Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a71e2ac1 upstream.

The NACKF flag should be cleared in INTRIICNAKI interrupt processing as
description in HW manual.

This issue shows up quickly when PREEMPT_RT is applied and a device is
probed that is not plugged in (like a touchscreen controller). The result
is endless interrupts that halt system boot.

Fixes: 310c18a4

 ("i2c: riic: add driver")
Cc: stable@vger.kernel.org
Reported-by: Chien Nguyen <chien.nguyen.eb@rvc.renesas.com>
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 78887832

 upstream.

add_early_randomness() is called by hwrng_register() when the
hardware is added. If this hardware and its module are present
at boot, and if there is no data available the boot hangs until
data are available and can't be interrupted.

For instance, in the case of virtio-rng, in some cases the host can be
not able to provide enough entropy for all the guests.

We can have two easy ways to reproduce the problem but they rely on
misconfiguration of the hypervisor or the egd daemon:

- if virtio-rng device is configured to connect to the egd daemon of the
host but when the virtio-rng driver asks for data the daemon is not
connected,

- if virtio-rng device is configured to connect to the egd daemon of the
host but the egd daemon doesn't provide data.

The guest kernel will hang at boot until the virtio-rng driver provides
enough data.

To avoid that, call rng_get_data() in non-blocking mode (wait=0)
from add_early_randomness().

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Fixes: d9e79726

 ("hwrng: add randomness to system from rng...")
Cc: <stable@vger.kernel.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 6565c182 upstream.

Quoted from
commit 3da40c7b ("ext4: only call ext4_truncate when size <= isize")

" At LSF we decided that if we truncate up from isize we shouldn't trim
  fallocated blocks that were fallocated with KEEP_SIZE and are past the
 new i_size.  This patch fixes ext4 to do this. "

And generic/092 of fstest have covered this case for long time, however
is_quota_modification() didn't adjust based on that rule, so that in
below condition, we will lose to quota block change:
- fallocate blocks beyond EOF
- remount
- truncate(file_path, file_size)

Fix it.

Link: https://lore.kernel.org/r/20190911093650.35329-1-yuchao0@huawei.com
Fixes: 3da40c7b

 ("ext4: only call ext4_truncate when size <= isize")
CC: stable@vger.kernel.org
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c1e8220b

 upstream.

If a program attempts to punch a hole on an inline data file, we need
to convert it to a normal file first.

This was detected using ext4/032 using the adv configuration.  Simple
reproducer:

mke2fs -Fq -t ext4 -O inline_data /dev/vdc
mount /vdc
echo "" > /vdc/testfile
xfs_io -c 'truncate 33554432' /vdc/testfile
xfs_io -c 'fpunch 0 1048576' /vdc/testfile
umount /vdc
e2fsck -fy /dev/vdc

Cc: stable@vger.kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 8619e5bd

 upstream.

syzbot found that a thread can stall for minutes inside read_mem() or
write_mem() after that thread was killed by SIGKILL [1]. Reading from
iomem areas of /dev/mem can be slow, depending on the hardware.
While reading 2GB at one read() is legal, delaying termination of killed
thread for minutes is bad. Thus, allow reading/writing /dev/mem and
/dev/kmem to be preemptible and killable.

  [ 1335.912419][T20577] read_mem: sz=4096 count=2134565632
  [ 1335.943194][T20577] read_mem: sz=4096 count=2134561536
  [ 1335.978280][T20577] read_mem: sz=4096 count=2134557440
  [ 1336.011147][T20577] read_mem: sz=4096 count=2134553344
  [ 1336.041897][T20577] read_mem: sz=4096 count=2134549248

Theoretically, reading/writing /dev/mem and /dev/kmem can become
"interruptible". But this patch chose "killable". Future patch will make
them "interruptible" so that we can revert to "killable" if some program
regressed.

[1] https://syzkaller.appspot.com/bug?id=a0e3436829698d5824231251fad9d8e998f94f5e

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: stable <stable@vger.kernel.org>
Reported-by: syzbot <syzbot+8ab2d0f39fb79fe6ca40@syzkaller.appspotmail.com>
Link: https://lore.kernel.org/r/1566825205-10703-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c1d3ad84

 upstream.

Currently frame registrations are not purged, even when changing the
interface type.  This can lead to potentially weird situations where
frames possibly not allowed on a given interface type remain registered
due to the type switching happening after registration.

The kernel currently relies on userspace apps to actually purge the
registrations themselves, this is not something that the kernel should
rely on.

Add a call to cfg80211_mlme_purge_registrations() to forcefully remove
any registrations left over prior to switching the iftype.

Cc: stable@vger.kernel.org
Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Link: https://lore.kernel.org/r/20190828211110.15005-1-denkenz@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 143f6e73 upstream.

7471fb77

 ("md/raid6: Fix anomily when recovering a single device in
RAID6.") avoids rereading P when it can be computed from other members.
However, this misses the chance to re-write the right data to P. This
patch sets R5_ReadError if the re-read fails.

Also, when re-read is skipped, we also missed the chance to reset
rdev->read_errors to 0. It can fail the disk when there are many read
errors on P member disk (other disks don't have read error)

V2: upper layer read request don't read parity/Q data. So there is no
need to consider such situation.

This is Reported-by: kbuild test robot <lkp@intel.com>

Fixes: 7471fb77

 ("md/raid6: Fix anomily when recovering a single device in RAID6.")
Cc: <stable@vger.kernel.org> #4.4+
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f18ddc13 upstream.

ENOTSUPP is not supposed to be returned to userspace. This was found on an
OpenPower machine, where the RTC does not support set_alarm.

On that system, a clock_nanosleep(CLOCK_REALTIME_ALARM, ...) results in
"524 Unknown error 524"

Replace it with EOPNOTSUPP which results in the expected "95 Operation not
supported" error.

Fixes: 1c6b39ad

 (alarmtimers: Return -ENOTSUPP if no RTC device is present)
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190903171802.28314-1-cascardo@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit b7005d4e upstream.

This fixes a kernel panic on memcpy when
FORTIFY_SOURCE is enabled.

The initial smp implementation on commit aa7eb2bb
("arm: zynq: Add smp support")
used memcpy, which worked fine until commit ee333554
("ARM: 8749/1: Kconfig: Add ARCH_HAS_FORTIFY_SOURCE")
enabled overflow checks at runtime, producing a read
overflow panic.

The computed size of memcpy args are:
- p_size (dst): 4294967295 = (size_t) -1
- q_size (src): 1
- size (len): 8

Additionally, the memory is marked as __iomem, so one of
the memcpy_* functions should be used for read/write.

Fixes: aa7eb2bb

 ("arm: zynq: Add smp support")
Signed-off-by: Luis Araneda <luaraneda@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 810f3b86

 upstream.

If ipc->ops.reply_msg_match is NULL, we may end up using uninitialized
mask value.

reported by smatch:
sound/soc/intel/common/sst-ipc.c:266 sst_ipc_reply_find_msg() error: uninitialized symbol 'mask'.

Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@intel.com>
Link: https://lore.kernel.org/r/20190827141712.21015-3-amadeuszx.slawinski@linux.intel.com
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 7e0bb582

 upstream.

Like a bunch of other MSI laptops the MS-1039 uses a 0c45:627b
SN9C201 + OV7660 webcam which is mounted upside down.

Add it to the sn9c20x flip_dmi_table to deal with this.

Cc: stable@vger.kernel.org
Reported-by: Rui Salvaterra <rsalvaterra@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 16cfacc8 upstream.

Manually generate the PDPTR reserved bit mask when explicitly loading
PDPTRs.  The reserved bits that are being tracked by the MMU reflect the
current paging mode, which is unlikely to be PAE paging in the vast
majority of flows that use load_pdptrs(), e.g. CR0 and CR4 emulation,
__set_sregs(), etc...  This can cause KVM to incorrectly signal a bad
PDPTR, or more likely, miss a reserved bit check and subsequently fail
a VM-Enter due to a bad VMCS.GUEST_PDPTR.

Add a one off helper to generate the reserved bits instead of sharing
code across the MMU's calculations and the PDPTR emulation.  The PDPTR
reserved bits are basically set in stone, and pushing a helper into
the MMU's calculation adds unnecessary complexity without improving
readability.

Oppurtunistically fix/update the comment for load_pdptrs().

Note, the buggy commit also introduced a deliberate functional change,
"Also remove bit 5-6 from rsvd_bits_mask per latest SDM.", which was
effectively (and correctly) reverted by commit cd9ae5fe ("KVM: x86:
Fix page-tables reserved bits").  A bit of SDM archaeology shows that
the SDM from late 2008 had a bug (likely a copy+paste error) where it
listed bits 6:5 as AVL and A for PDPTEs used for 4k entries but reserved
for 2mb entries.  I.e. the SDM contradicted itself, and bits 6:5 are and
always have been reserved.

Fixes: 20c466b5

 ("KVM: Use rsvd_bits_mask in load_pdptrs()")
Cc: stable@vger.kernel.org
Cc: Nadav Amit <nadav.amit@gmail.com>
Reported-by: Doug Reiland <doug.reiland@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c8848cee upstream.

x86_emulate_instruction() takes into account ctxt->have_exception flag
during instruction decoding, but in practice this flag is never set in
x86_decode_insn().

Fixes: 6ea6e843

 ("KVM: x86: inject exceptions produced by x86_decode_insn")
Cc: stable@vger.kernel.org
Cc: Denis Lunev <den@virtuozzo.com>
Cc: Roman Kagan <rkagan@virtuozzo.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Signed-off-by: Jan Dakinevich <jan.dakinevich@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 8530a79c upstream.

inject_emulated_exception() returns true if and only if nested page
fault happens. However, page fault can come from guest page tables
walk, either nested or not nested. In both cases we should stop an
attempt to read under RIP and give guest to step over its own page
fault handler.

This is also visible when an emulated instruction causes a #GP fault
and the VMware backdoor is enabled.  To handle the VMware backdoor,
KVM intercepts #GP faults; with only the next patch applied,
x86_emulate_instruction() injects a #GP but returns EMULATE_FAIL
instead of EMULATE_DONE.   EMULATE_FAIL causes handle_exception_nmi()
(or gp_interception() for SVM) to re-inject the original #GP because it
thinks emulation failed due to a non-VMware opcode.  This patch prevents
the issue as x86_emulate_instruction() will return EMULATE_DONE after
injecting the #GP.

Fixes: 6ea6e843

 ("KVM: x86: inject exceptions produced by x86_decode_insn")
Cc: stable@vger.kernel.org
Cc: Denis Lunev <den@virtuozzo.com>
Cc: Roman Kagan <rkagan@virtuozzo.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Signed-off-by: Jan Dakinevich <jan.dakinevich@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 5fa16591

 upstream.

The HP Dino PCI controller chip can be used in two variants: as on-board
controller (e.g. in B160L), or on an Add-On card ("Card-Mode") to bridge
PCI components to systems without a PCI bus, e.g. to a HSC/GSC bus.  One
such Add-On card is the HP HSC-PCI Card which has one or more DEC Tulip
PCI NIC chips connected to the on-card Dino PCI controller.

Dino in Card-Mode has a big disadvantage: All PCI memory accesses need
to go through the DINO_MEM_DATA register, so Linux drivers will not be
able to use the ioremap() function. Without ioremap() many drivers will
not work, one example is the tulip driver which then simply crashes the
kernel if it tries to access the ports on the HP HSC card.

This patch disables the HP HSC card if it finds one, and as such
fixes the kernel crash on a HP D350/2 machine.

Signed-off-by: Helge Deller <deller@gmx.de>
Noticed-by: Phil Scarr <phil.scarr@pm.me>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d5880c7a

 upstream.

unlock_page() was missing in case of an already in-flight write against the
same page.

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Fixes: ff17be08

 ("fuse: writepage: skip already in flight")
Cc: <stable@vger.kernel.org> # v3.13
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit b46eff55ad5bd98e746c0a7022fe7ee071de5fee ]

kmsg_dump_get_buffer() is supposed to select all the youngest log
messages which fit into the provided buffer.  It determines the correct
start index by using msg_print_text() with a NULL buffer to calculate
the size of each entry.  However, when performing the actual writes,
msg_print_text() only writes the entry to the buffer if the written len
is lesser than the size of the buffer.  So if the lengths of the
selected youngest log messages happen to precisely fill up the provided
buffer, the last log message is not included.

We don't want to modify msg_print_text() to fill up the buffer and start
returning a length which is equal to the size of the buffer, since
callers of its other users, such as kmsg_dump_get_line(), depend upon
the current behaviour.

Instead, fix kmsg_dump_get_buffer() to compensate for this.

For example, with the following two final prints:

[    6.427502] AAAAAAAAAAAAA
[    6.427769] BBBBBBBB12345

A dump of a 64-byte buffer filled by kmsg_dump_get_buffer(), before this
patch:

 00000000: 3c 30 3e 5b 20 20 20 20 36 2e 35 32 32 31 39 37  <0>[    6.522197
 00000010: 5d 20 41 41 41 41 41 41 41 41 41 41 41 41 41 0a  ] AAAAAAAAAAAAA.
 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................

After this patch:

 00000000: 3c 30 3e 5b 20 20 20 20 36 2e 34 35 36 36 37 38  <0>[    6.456678
 00000010: 5d 20 42 42 42 42 42 42 42 42 31 32 33 34 35 0a  ] BBBBBBBB12345.
 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................

Link: http://lkml.kernel.org/r/20190711142937.4083-1-vincent.whitchurch@axis.com
Fixes: e2ae715d

 ("kmsg - kmsg_dump() use iterator to receive log buffer content")
To: rostedt@goodmis.org
Cc: linux-kernel@vger.kernel.org
Cc: <stable@vger.kernel.org> # v3.5+
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

commit e1a00b5b upstream.

2 bytes in MSB of register for clock status is zero during intermediate
state after changing status of sampling clock in models of TASCAM FireWire
series. The duration of this state differs depending on cases. During the
state, it's better to retry reading the register for current status of
the clock.

In current implementation, the intermediate state is checked only when
getting current sampling transmission frequency, then retry reading.
This care is required for the other operations to read the register.

This commit moves the codes of check and retry into helper function
commonly used for operations to read the register.

Fixes: e453df44

 ("ALSA: firewire-tascam: add PCM functionality")
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20190910135152.29800-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 2617120f upstream.

The return value of snd_tscm_stream_get_clock() is ignored. This commit
checks the value and handle error.

Fixes: e453df44

 ("ALSA: firewire-tascam: add PCM functionality")
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20190910135152.29800-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit e9eb103f

 ]

The omap3isp driver registered subdevs without the dev field being set. Do
that now.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 2a28468e

 ]

[BUG]
With fuzzed image and MIXED_GROUPS super flag, we can hit the following
BUG_ON():

  kernel BUG at fs/btrfs/delayed-ref.c:491!
  invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 0 PID: 1849 Comm: sync Tainted: G           O      5.2.0-custom #27
  RIP: 0010:update_existing_head_ref.cold+0x44/0x46 [btrfs]
  Call Trace:
   add_delayed_ref_head+0x20c/0x2d0 [btrfs]
   btrfs_add_delayed_tree_ref+0x1fc/0x490 [btrfs]
   btrfs_free_tree_block+0x123/0x380 [btrfs]
   __btrfs_cow_block+0x435/0x500 [btrfs]
   btrfs_cow_block+0x110/0x240 [btrfs]
   btrfs_search_slot+0x230/0xa00 [btrfs]
   ? __lock_acquire+0x105e/0x1e20
   btrfs_insert_empty_items+0x67/0xc0 [btrfs]
   alloc_reserved_file_extent+0x9e/0x340 [btrfs]
   __btrfs_run_delayed_refs+0x78e/0x1240 [btrfs]
   ? kvm_clock_read+0x18/0x30
   ? __sched_clock_gtod_offset+0x21/0x50
   btrfs_run_delayed_refs.part.0+0x4e/0x180 [btrfs]
   btrfs_run_delayed_refs+0x23/0x30 [btrfs]
   btrfs_commit_transaction+0x53/0x9f0 [btrfs]
   btrfs_sync_fs+0x7c/0x1c0 [btrfs]
   ? __ia32_sys_fdatasync+0x20/0x20
   sync_fs_one_sb+0x23/0x30
   iterate_supers+0x95/0x100
   ksys_sync+0x62/0xb0
   __ia32_sys_sync+0xe/0x20
   do_syscall_64+0x65/0x240
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

[CAUSE]
This situation is caused by several factors:
- Fuzzed image
  The extent tree of this fs missed one backref for extent tree root.
  So we can allocated space from that slot.

- MIXED_BG feature
  Super block has MIXED_BG flag.

- No mixed block groups exists
  All block groups are just regular ones.

This makes data space_info->block_groups[] contains metadata block
groups.  And when we reserve space for data, we can use space in
metadata block group.

Then we hit the following file operations:

- fallocate
  We need to allocate data extents.
  find_free_extent() choose to use the metadata block to allocate space
  from, and choose the space of extent tree root, since its backref is
  missing.

  This generate one delayed ref head with is_data = 1.

- extent tree update
  We need to update extent tree at run_delayed_ref time.

  This generate one delayed ref head with is_data = 0, for the same
  bytenr of old extent tree root.

Then we trigger the BUG_ON().

[FIX]
The quick fix here is to check block_group->flags before using it.

The problem can only happen for MIXED_GROUPS fs. Regular filesystems
won't have space_info with DATA|METADATA flag, and no way to hit the
bug.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203255
Reported-by: Jungyeon Yoon <jungyeon.yoon@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 051c78af

 ]

Lenovo ThinkCentre M73 and M93 don't seem to have a proper beep
although the driver tries to probe and set up blindly.
Blacklist these machines for suppressing the beep creation.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204635
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit a10feaf8

 ]

The function at issue does not always initialize each byte allocated
for 'b' and can therefore leak uninitialized memory to a USB device in
the call to usb_bulk_msg()

Use kzalloc() instead of kmalloc()

Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
Reported-by:  <syzbot+0522702e9d67142379f1@syzkaller.appspotmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 764f3f1e

 ]

This sentinel tells the firmware loading process when to stop.

Reported-and-tested-by:  <syzbot+98156c174c5a2cad9f8f@syzkaller.appspotmail.com>
Signed-off-by: Kevin Easton <kevin@guarana.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit c894e33d

 ]

When switching from any MMC speed mode that requires 1.8v
(HS200, HS400 and HS400ES) to High Speed (HS) mode, the system
ends up configured for SDR12 with a 50MHz clock which is an illegal
mode.

This happens because the SDHCI_CTRL_VDD_180 bit in the
SDHCI_HOST_CONTROL2 register is left set and when this bit is
set, the speed mode is controlled by the SDHCI_CTRL_UHS field
in the SDHCI_HOST_CONTROL2 register. The SDHCI_CTRL_UHS field
will end up being set to 0 (SDR12) by sdhci_set_uhs_signaling()
because there is no UHS mode being set.

The fix is to change sdhci_set_uhs_signaling() to set the
SDHCI_CTRL_UHS field to SDR25 (which is the same as HS) for
any switch to HS mode.

This was found on a new eMMC controller that does strict checking
of the speed mode and the corresponding clock rate. It caused the
switch to HS400 mode to fail because part of the sequence to switch
to HS400 requires a switch from HS200 to HS before going to HS400.

Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Al Cooper <alcooperx@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 2ec42f31

 ]

Some tools use the snd_pcm_info_get_name() to try to identify PCMs or for
other purposes.

Currently it is left empty with the dmaengine-pcm, in this case copy the
pcm->id string as pcm->name.

For example IGT is using this to find the HDMI PCM for testing audio on it.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reported-by: Arthur She <arthur.she@linaro.org>
Link: https://lore.kernel.org/r/20190906055524.7393-1-peter.ujfalusi@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit e336b402

 ]

Since BUG() and WARN() may use a trap (e.g. UD2 on x86) to
get the address where the BUG() has occurred, kprobes can not
do single-step out-of-line that instruction. So prohibit
probing on such address.

Without this fix, if someone put a kprobe on WARN(), the
kernel will crash with invalid opcode error instead of
outputing warning message, because kernel can not find
correct bug address.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S . Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naveen N . Rao <naveen.n.rao@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/156750890133.19112.3393666300746167111.stgit@devnote2
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit c5dbe606

 ]

Skip resetting paRAM slots marked as reserved as they might be used by
other cores.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20190823125618.8133-2-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 07f1a685

 ]

When run test case:
  mdadm -CR /dev/md1 -l 1 -n 4 /dev/sd[a-d] --assume-clean --bitmap=internal
  mdadm -S /dev/md1
  mdadm -A /dev/md1 /dev/sd[b-c] --run --force

  mdadm --zero /dev/sda
  mdadm /dev/md1 -a /dev/sda

  echo offline > /sys/block/sdc/device/state
  echo offline > /sys/block/sdb/device/state
  sleep 5
  mdadm -S /dev/md1

  echo running > /sys/block/sdb/device/state
  echo running > /sys/block/sdc/device/state
  mdadm -A /dev/md1 /dev/sd[a-c] --run --force

mdadm run fail with kernel message as follow:
[  172.986064] md: kicking non-fresh sdb from array!
[  173.004210] md: kicking non-fresh sdc from array!
[  173.022383] md/raid1:md1: active with 0 out of 4 mirrors
[  173.022406] md1: failed to create bitmap (-5)

In fact, when active disk in raid1 array less than one, we
need to return fail in raid1_run().

Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 6e4d91aa

 ]

At boot time, the acpi_power_meter driver logs the following error level
message: "Ignoring unsafe software power cap". Having read about it from
a few sources, it seems that the error message can be quite misleading.

While the message can imply that Linux is ignoring the fact that the
system is operating in potentially dangerous conditions, the truth is
the driver found an ACPI_PMC object that supports software power
capping. The driver simply decides not to use it, perhaps because it
doesn't support the object.

The best solution is probably changing the log level from error to warning.
All sources I have found, regarding the error, have downplayed its
significance. There is not much of a reason for it to be on error level,
while causing potential confusions or misinterpretations.

Signed-off-by: Wang Shenran <shenran268@gmail.com>
Link: https://lore.kernel.org/r/20190724080110.6952-1-shenran268@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 03d1571d ]

In cm_write(), 'buf' is allocated through kzalloc(). In the following
execution, if an error occurs, 'buf' is not deallocated, leading to memory
leaks. To fix this issue, free 'buf' before returning the error.

Fixes: 526b4af4

 ("ACPI: Split out custom_method functionality into an own driver")
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit e97fd138

 ]

To be compliant with XDG user directory layout, the user's plugin
directory is changed from ~/.traceevent/plugins to
~/.local/lib/traceevent/plugins/

Suggested-by: Patrick McLean <chutzpah@gentoo.org>
Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Patrick McLean <chutzpah@gentoo.org>
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/linux-trace-devel/20190313144206.41e75cf8@patrickm/
Link: http://lore.kernel.org/linux-trace-devel/20190801074959.22023-4-tz.stoyanov@gmail.com
Link: http://lore.kernel.org/lkml/20190805204355.344622683@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 4c4cdc4c

 ]

According to the ACPI 6.3 specification, the _PSD method is optional
when using CPPC.  The underlying assumption is that each CPU can change
frequency independently from all other CPUs; _PSD is provided to tell
the OS that some processors can NOT do that.

However, the acpi_get_psd() function returns ENODEV if there is no _PSD
method present, or an ACPI error status if an error occurs when evaluating
_PSD, if present.  This makes _PSD mandatory when using CPPC, in violation
of the specification, and only on Linux.

This has forced some firmware writers to provide a dummy _PSD, even though
it is irrelevant, but only because Linux requires it; other OSPMs follow
the spec.  We really do not want to have OS specific ACPI tables, though.

So, correct acpi_get_psd() so that it does not return an error if there
is no _PSD method present, but does return a failure when the method can
not be executed properly.  This allows _PSD to be optional as it should
be.

Signed-off-by: Al Stone <ahs3@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 093347ab

 ]

As pointed by cppcheck:

	[drivers/media/i2c/ov9650.c:706]: (error) Shifting by a negative value is undefined behaviour
	[drivers/media/i2c/ov9650.c:707]: (error) Shifting by a negative value is undefined behaviour
	[drivers/media/i2c/ov9650.c:721]: (error) Shifting by a negative value is undefined behaviour

Prevent mangling with gains with invalid values.

As pointed by Sylvester, this should never happen in practice,
as min value of V4L2_CID_GAIN control is 16 (gain is always >= 16
and m is always >= 0), but it is too hard for a static analyzer
to get this, as the logic with validates control min/max is
elsewhere inside V4L2 core.

Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>