[ Upstream commit 65161c35

 ]

Eliminate the follow smatch warning:

drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c:1227
bnx2x_iov_init_one() warn: missing error code 'err'.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 78cf0eb9 ]

When update the latest mainline kernel with the following three configs,
the kernel hangs during startup:

(1) CONFIG_FUNCTION_GRAPH_TRACER=y
(2) CONFIG_PREEMPT_TRACER=y
(3) CONFIG_FTRACE_STARTUP_TEST=y

When update the latest mainline kernel with the above two configs (1)
and (2), the kernel starts normally, but it still hangs when execute
the following command:

echo "function_graph" > /sys/kernel/debug/tracing/current_tracer

Without CONFIG_PREEMPT_TRACER=y, the above two kinds of kernel hangs
disappeared, so it seems that CONFIG_PREEMPT_TRACER has some influences
with function_graph tracer at the first glance.

I use ejtag to find out the epc address is related with preempt_enable()
in the file arch/mips/lib/mips-atomic.c, because function tracing can
trace the preempt_{enable,disable} calls that are traced, replace them
with preempt_{enable,disable}_notrace to prevent function tracing from
going into an infinite loop, and then it can fix the kernel hang issue.

By the way, it seems that this commit is a complement and improvement of
commit f93a1a00

 ("MIPS: Fix crash that occurs when function tracing
is enabled").

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit a4dd4fc6

 ]

In cops_probe1(), there is a write to dev->base_addr after requesting an
interrupt line and registering the interrupt handler cops_interrupt().
The handler might be called in parallel to handle an interrupt.
cops_interrupt() tries to read dev->base_addr leading to a potential
data race. So write to dev->base_addr before calling request_irq().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Saubhik Mukherjee <saubhik.mukherjee@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 5eff1461 ]

If runtime power menagement is enabled, the gigabit ethernet PLL would
be disabled after macb_probe(). During this period of time, the system
would hang up if we try to access GEMGXL control registers.

We can't put runtime_pm_get/runtime_pm_put/ there due to the issue of
sleep inside atomic section (7fa2955f

 ("sh_eth: Fix sleeping
function called from invalid context"). Add netif_running checking to
ensure the device is available before accessing GEMGXL device.

Changed in v2:
 - Use netif_running instead of its own flag

Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 2ef7665d

 ]

Target de-configuration panics at high CPU load because TPGT and WWPN can
be removed on separate threads.

TPGT removal requests a reset HBA on a separate thread and waits for reset
complete (phase1). Due to high CPU load that HBA reset can be delayed for
some time.

WWPN removal does qlt_stop_phase2(). There it is believed that phase1 has
already completed and thus tgt.tgt_ops is subsequently cleared. However,
tgt.tgt_ops is needed to process incoming traffic and therefore this will
cause one of the following panics:

NIP qlt_reset+0x7c/0x220 [qla2xxx]
LR  qlt_reset+0x68/0x220 [qla2xxx]
Call Trace:
0xc000003ffff63a78 (unreliable)
qlt_handle_imm_notify+0x800/0x10c0 [qla2xxx]
qlt_24xx_atio_pkt+0x208/0x590 [qla2xxx]
qlt_24xx_process_atio_queue+0x33c/0x7a0 [qla2xxx]
qla83xx_msix_atio_q+0x54/0x90 [qla2xxx]

or

NIP qlt_24xx_handle_abts+0xd0/0x2a0 [qla2xxx]
LR  qlt_24xx_handle_abts+0xb4/0x2a0 [qla2xxx]
Call Trace:
qlt_24xx_handle_abts+0x90/0x2a0 [qla2xxx] (unreliable)
qlt_24xx_process_atio_queue+0x500/0x7a0 [qla2xxx]
qla83xx_msix_atio_q+0x54/0x90 [qla2xxx]

or

NIP qlt_create_sess+0x90/0x4e0 [qla2xxx]
LR  qla24xx_do_nack_work+0xa8/0x180 [qla2xxx]
Call Trace:
0xc0000000348fba30 (unreliable)
qla24xx_do_nack_work+0xa8/0x180 [qla2xxx]
qla2x00_do_work+0x674/0xbf0 [qla2xxx]
qla2x00_iocb_work_fn

The patch fixes the issue by serializing qlt_stop_phase1() and
qlt_stop_phase2() functions to make WWPN removal wait for phase1
completion.

Link: https://lore.kernel.org/r/20210415203554.27890-1-d.bogdanov@yadro.com
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit e662502b

 ]

Some commands (such as INQUIRY) may return less data than the initiator
requested. To avoid conducting useless information, set the right residual
count to make upper layer aware of this.

Before (INQUIRY PAGE 0xB0 with 128B buffer):

$ sg_raw -r 128 /dev/sda 12 01 B0 00 80 00
SCSI Status: Good

Received 128 bytes of data:
 00 00 b0 00 3c 01 00 00 00 00 00 00 00 00 00 00 00 ...<............
 10 00 00 00 00 00 01 00 00 00 00 00 40 00 00 08 00 ...........@....
 20 80 00 00 00 00 00 00 00 00 00 20 00 00 00 00 00 .......... .....
 30 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 40 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 50 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 60 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

After:

$ sg_raw -r 128 /dev/sda 12 01 B0 00 80 00
SCSI Status: Good

Received 64 bytes of data:
00 00 b0 00 3c 01 00 00 00 00 00 00 00 00 00 00 00 ...<............
10 00 00 00 00 00 01 00 00 00 00 00 40 00 00 08 00 ...........@....
20 80 00 00 00 00 00 00 00 00 00 20 00 00 00 00 00 .......... .....
30 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

[mkp: clarified description]

Link: https://lore.kernel.org/r/03C41093-B62E-43A2-913E-CFC92F1C70C3@vmware.com
Signed-off-by: Matt Wang <wwentao@vmware.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 13a6f315

 ]

When calling the 'ql_sem_spinlock', the driver has already acquired the
spin lock, so the driver should not call 'ssleep' in atomic context.

This bug can be fixed by using 'mdelay' instead of 'ssleep'.

The KASAN's log reveals it:

[    3.238124 ] BUG: scheduling while atomic: swapper/0/1/0x00000002
[    3.238748 ] 2 locks held by swapper/0/1:
[    3.239151 ]  #0: ffff88810177b240 (&dev->mutex){....}-{3:3}, at:
__device_driver_lock+0x41/0x60
[    3.240026 ]  #1: ffff888107c60e28 (&qdev->hw_lock){....}-{2:2}, at:
ql3xxx_probe+0x2aa/0xea0
[    3.240873 ] Modules linked in:
[    3.241187 ] irq event stamp: 460854
[    3.241541 ] hardirqs last  enabled at (460853): [<ffffffff843051bf>]
_raw_spin_unlock_irqrestore+0x4f/0x70
[    3.242245 ] hardirqs last disabled at (460854): [<ffffffff843058ca>]
_raw_spin_lock_irqsave+0x2a/0x70
[    3.242245 ] softirqs last  enabled at (446076): [<ffffffff846002e4>]
__do_softirq+0x2e4/0x4b1
[    3.242245 ] softirqs last disabled at (446069): [<ffffffff811ba5e0>]
irq_exit_rcu+0x100/0x110
[    3.242245 ] Preemption disabled at:
[    3.242245 ] [<ffffffff828ca5ba>] ql3xxx_probe+0x2aa/0xea0
[    3.242245 ] Kernel panic - not syncing: scheduling while atomic
[    3.242245 ] CPU: 2 PID: 1 Comm: swapper/0 Not tainted
5.13.0-rc1-00145
-gee7dc339169-dirty #16
[    3.242245 ] Call Trace:
[    3.242245 ]  dump_stack+0xba/0xf5
[    3.242245 ]  ? ql3xxx_probe+0x1f0/0xea0
[    3.242245 ]  panic+0x15a/0x3f2
[    3.242245 ]  ? vprintk+0x76/0x150
[    3.242245 ]  ? ql3xxx_probe+0x2aa/0xea0
[    3.242245 ]  __schedule_bug+0xae/0xe0
[    3.242245 ]  __schedule+0x72e/0xa00
[    3.242245 ]  schedule+0x43/0xf0
[    3.242245 ]  schedule_timeout+0x28b/0x500
[    3.242245 ]  ? del_timer_sync+0xf0/0xf0
[    3.242245 ]  ? msleep+0x2f/0x70
[    3.242245 ]  msleep+0x59/0x70
[    3.242245 ]  ql3xxx_probe+0x307/0xea0
[    3.242245 ]  ? _raw_spin_unlock_irqrestore+0x3a/0x70
[    3.242245 ]  ? pci_device_remove+0x110/0x110
[    3.242245 ]  local_pci_probe+0x45/0xa0
[    3.242245 ]  pci_device_probe+0x12b/0x1d0
[    3.242245 ]  really_probe+0x2a9/0x610
[    3.242245 ]  driver_probe_device+0x90/0x1d0
[    3.242245 ]  ? mutex_lock_nested+0x1b/0x20
[    3.242245 ]  device_driver_attach+0x68/0x70
[    3.242245 ]  __driver_attach+0x124/0x1b0
[    3.242245 ]  ? device_driver_attach+0x70/0x70
[    3.242245 ]  bus_for_each_dev+0xbb/0x110
[    3.242245 ]  ? rdinit_setup+0x45/0x45
[    3.242245 ]  driver_attach+0x27/0x30
[    3.242245 ]  bus_add_driver+0x1eb/0x2a0
[    3.242245 ]  driver_register+0xa9/0x180
[    3.242245 ]  __pci_register_driver+0x82/0x90
[    3.242245 ]  ? yellowfin_init+0x25/0x25
[    3.242245 ]  ql3xxx_driver_init+0x23/0x25
[    3.242245 ]  do_one_initcall+0x7f/0x3d0
[    3.242245 ]  ? rdinit_setup+0x45/0x45
[    3.242245 ]  ? rcu_read_lock_sched_held+0x4f/0x80
[    3.242245 ]  kernel_init_freeable+0x2aa/0x301
[    3.242245 ]  ? rest_init+0x2c0/0x2c0
[    3.242245 ]  kernel_init+0x18/0x190
[    3.242245 ]  ? rest_init+0x2c0/0x2c0
[    3.242245 ]  ? rest_init+0x2c0/0x2c0
[    3.242245 ]  ret_from_fork+0x1f/0x30
[    3.242245 ] Dumping ftrace buffer:
[    3.242245 ]    (ftrace buffer empty)
[    3.242245 ] Kernel Offset: disabled
[    3.242245 ] Rebooting in 1 seconds.

Reported-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 940d71c6

 ]

If VCPU is suspended (VM suspend) in wq_watchdog_timer_fn() then
once this VCPU resumes it will see the new jiffies value, while it
may take a while before IRQ detects PVCLOCK_GUEST_STOPPED on this
VCPU and updates all the watchdogs via pvclock_touch_watchdogs().
There is a small chance of misreported WQ stalls in the meantime,
because new jiffies is time_after() old 'ts + thresh'.

wq_watchdog_timer_fn()
{
	for_each_pool(pool, pi) {
		if (time_after(jiffies, ts + thresh)) {
			pr_emerg("BUG: workqueue lockup - pool");
		}
	}
}

Save jiffies at the beginning of this function and use that value
for stall detection. If VM gets suspended then we continue using
"old" jiffies value and old WQ touch timestamps. If IRQ at some
point restarts the stall detection cycle (pvclock_touch_watchdogs())
then old jiffies will always be before new 'ts + thresh'.

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 45e1ba40 ]

This patch effectively reverts the commit a3e72739 ("cgroup: fix
too early usage of static_branch_disable()"). The commit 6041186a
("init: initialize jump labels before command line option parsing") has
moved the jump_label_init() before parse_args() which has made the
commit a3e72739

 unnecessary. On the other hand there are
consequences of disabling the controllers later as there are subsystems
doing the controller checks for different decisions. One such incident
is reported [1] regarding the memory controller and its impact on memory
reclaim code.

[1] https://lore.kernel.org/linux-mm/921e53f3-4b13-aab8-4a9e-e83ff15371e4@nec.com

Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reported-by: NOMURA JUNICHI(野村　淳一) <junichi.nomura@nec.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Jun'ichi Nomura <junichi.nomura@nec.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 1dde47a6

 ]

We spotted a bug recently during a review where a driver was
unregistering a bus that wasn't registered, which would trigger this
BUG_ON().  Let's handle that situation more gracefully, and just print
a warning and return.

Reported-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 1d482e66

 ]

Syzbot reports that in mac80211 we have a potential deadlock
between our "local->stop_queue_reasons_lock" (spinlock) and
netlink's nl_table_lock (rwlock). This is because there's at
least one situation in which we might try to send a netlink
message with this spinlock held while it is also possible to
take the spinlock from a hardirq context, resulting in the
following deadlock scenario reported by lockdep:

       CPU0                    CPU1
       ----                    ----
  lock(nl_table_lock);
                               local_irq_disable();
                               lock(&local->queue_stop_reason_lock);
                               lock(nl_table_lock);
  <Interrupt>
    lock(&local->queue_stop_reason_lock);

This seems valid, we can take the queue_stop_reason_lock in
any kind of context ("CPU0"), and call ieee80211_report_ack_skb()
with the spinlock held and IRQs disabled ("CPU1") in some
code path (ieee80211_do_stop() via ieee80211_free_txskb()).

Short of disallowing netlink use in scenarios like these
(which would be rather complex in mac80211's case due to
the deep callchain), it seems the only fix for this is to
disable IRQs while nl_table_lock is held to avoid hitting
this scenario, this disallows the "CPU0" portion of the
reported deadlock.

Note that the writer side (netlink_table_grab()) already
disables IRQs for this lock.

Unfortunately though, this seems like a huge hammer, and
maybe the whole netlink table locking should be reworked.

Reported-by:  <syzbot+69ff9dff50dcfe14ddd4@syzkaller.appspotmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 35d96e63

 ]

If bond_kobj_init() or later kzalloc() in bond_alloc_slave() fail,
then we call kobject_put() on the slave->kobj. This in turn calls
the release function slave_kobj_release() which will always try to
cancel_delayed_work_sync(&slave->notify_work), which shouldn't be
done on an uninitialized work struct.

Always initialize the work struct earlier to avoid problems here.

Syzbot bisected this down to a completely pointless commit, some
fault injection may have been at work here that caused the alloc
failure in the first place, which may interact badly with bisect.

Reported-by:  <syzbot+bfda097c12a00c8cae67@syzkaller.appspotmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 9f6f8525

 ]

'nj_setup' in netjet.c might fail with -EIO and in this case
'card->irq' is initialized and is bigger than zero. A subsequent call to
'nj_release' will free the irq that has not been requested.

Fix this bug by deleting the previous assignment to 'card->irq' and just
keep the assignment before 'request_irq'.

The KASAN's log reveals it:

[    3.354615 ] WARNING: CPU: 0 PID: 1 at kernel/irq/manage.c:1826
free_irq+0x100/0x480
[    3.355112 ] Modules linked in:
[    3.355310 ] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
5.13.0-rc1-00144-g25a1298726e #13
[    3.355816 ] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[    3.356552 ] RIP: 0010:free_irq+0x100/0x480
[    3.356820 ] Code: 6e 08 74 6f 4d 89 f4 e8 5e ac 09 00 4d 8b 74 24 18
4d 85 f6 75 e3 e8 4f ac 09 00 8b 75 c8 48 c7 c7 78 c1 2e 85 e8 e0 cf f5
ff <0f> 0b 48 8b 75 c0 4c 89 ff e8 72 33 0b 03 48 8b 43 40 4c 8b a0 80
[    3.358012 ] RSP: 0000:ffffc90000017b48 EFLAGS: 00010082
[    3.358357 ] RAX: 0000000000000000 RBX: ffff888104dc8000 RCX:
0000000000000000
[    3.358814 ] RDX: ffff8881003c8000 RSI: ffffffff8124a9e6 RDI:
00000000ffffffff
[    3.359272 ] RBP: ffffc90000017b88 R08: 0000000000000000 R09:
0000000000000000
[    3.359732 ] R10: ffffc900000179f0 R11: 0000000000001d04 R12:
0000000000000000
[    3.360195 ] R13: ffff888107dc6000 R14: ffff888107dc6928 R15:
ffff888104dc80a8
[    3.360652 ] FS:  0000000000000000(0000) GS:ffff88817bc00000(0000)
knlGS:0000000000000000
[    3.361170 ] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    3.361538 ] CR2: 0000000000000000 CR3: 000000000582e000 CR4:
00000000000006f0
[    3.362003 ] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[    3.362175 ] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[    3.362175 ] Call Trace:
[    3.362175 ]  nj_release+0x51/0x1e0
[    3.362175 ]  nj_probe+0x450/0x950
[    3.362175 ]  ? pci_device_remove+0x110/0x110
[    3.362175 ]  local_pci_probe+0x45/0xa0
[    3.362175 ]  pci_device_probe+0x12b/0x1d0
[    3.362175 ]  really_probe+0x2a9/0x610
[    3.362175 ]  driver_probe_device+0x90/0x1d0
[    3.362175 ]  ? mutex_lock_nested+0x1b/0x20
[    3.362175 ]  device_driver_attach+0x68/0x70
[    3.362175 ]  __driver_attach+0x124/0x1b0
[    3.362175 ]  ? device_driver_attach+0x70/0x70
[    3.362175 ]  bus_for_each_dev+0xbb/0x110
[    3.362175 ]  ? rdinit_setup+0x45/0x45
[    3.362175 ]  driver_attach+0x27/0x30
[    3.362175 ]  bus_add_driver+0x1eb/0x2a0
[    3.362175 ]  driver_register+0xa9/0x180
[    3.362175 ]  __pci_register_driver+0x82/0x90
[    3.362175 ]  ? w6692_init+0x38/0x38
[    3.362175 ]  nj_init+0x36/0x38
[    3.362175 ]  do_one_initcall+0x7f/0x3d0
[    3.362175 ]  ? rdinit_setup+0x45/0x45
[    3.362175 ]  ? rcu_read_lock_sched_held+0x4f/0x80
[    3.362175 ]  kernel_init_freeable+0x2aa/0x301
[    3.362175 ]  ? rest_init+0x2c0/0x2c0
[    3.362175 ]  kernel_init+0x18/0x190
[    3.362175 ]  ? rest_init+0x2c0/0x2c0
[    3.362175 ]  ? rest_init+0x2c0/0x2c0
[    3.362175 ]  ret_from_fork+0x1f/0x30
[    3.362175 ] Kernel panic - not syncing: panic_on_warn set ...
[    3.362175 ] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
5.13.0-rc1-00144-g25a1298726e #13
[    3.362175 ] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[    3.362175 ] Call Trace:
[    3.362175 ]  dump_stack+0xba/0xf5
[    3.362175 ]  ? free_irq+0x100/0x480
[    3.362175 ]  panic+0x15a/0x3f2
[    3.362175 ]  ? __warn+0xf2/0x150
[    3.362175 ]  ? free_irq+0x100/0x480
[    3.362175 ]  __warn+0x108/0x150
[    3.362175 ]  ? free_irq+0x100/0x480
[    3.362175 ]  report_bug+0x119/0x1c0
[    3.362175 ]  handle_bug+0x3b/0x80
[    3.362175 ]  exc_invalid_op+0x18/0x70
[    3.362175 ]  asm_exc_invalid_op+0x12/0x20
[    3.362175 ] RIP: 0010:free_irq+0x100/0x480
[    3.362175 ] Code: 6e 08 74 6f 4d 89 f4 e8 5e ac 09 00 4d 8b 74 24 18
4d 85 f6 75 e3 e8 4f ac 09 00 8b 75 c8 48 c7 c7 78 c1 2e 85 e8 e0 cf f5
ff <0f> 0b 48 8b 75 c0 4c 89 ff e8 72 33 0b 03 48 8b 43 40 4c 8b a0 80
[    3.362175 ] RSP: 0000:ffffc90000017b48 EFLAGS: 00010082
[    3.362175 ] RAX: 0000000000000000 RBX: ffff888104dc8000 RCX:
0000000000000000
[    3.362175 ] RDX: ffff8881003c8000 RSI: ffffffff8124a9e6 RDI:
00000000ffffffff
[    3.362175 ] RBP: ffffc90000017b88 R08: 0000000000000000 R09:
0000000000000000
[    3.362175 ] R10: ffffc900000179f0 R11: 0000000000001d04 R12:
0000000000000000
[    3.362175 ] R13: ffff888107dc6000 R14: ffff888107dc6928 R15:
ffff888104dc80a8
[    3.362175 ]  ? vprintk+0x76/0x150
[    3.362175 ]  ? free_irq+0x100/0x480
[    3.362175 ]  nj_release+0x51/0x1e0
[    3.362175 ]  nj_probe+0x450/0x950
[    3.362175 ]  ? pci_device_remove+0x110/0x110
[    3.362175 ]  local_pci_probe+0x45/0xa0
[    3.362175 ]  pci_device_probe+0x12b/0x1d0
[    3.362175 ]  really_probe+0x2a9/0x610
[    3.362175 ]  driver_probe_device+0x90/0x1d0
[    3.362175 ]  ? mutex_lock_nested+0x1b/0x20
[    3.362175 ]  device_driver_attach+0x68/0x70
[    3.362175 ]  __driver_attach+0x124/0x1b0
[    3.362175 ]  ? device_driver_attach+0x70/0x70
[    3.362175 ]  bus_for_each_dev+0xbb/0x110
[    3.362175 ]  ? rdinit_setup+0x45/0x45
[    3.362175 ]  driver_attach+0x27/0x30
[    3.362175 ]  bus_add_driver+0x1eb/0x2a0
[    3.362175 ]  driver_register+0xa9/0x180
[    3.362175 ]  __pci_register_driver+0x82/0x90
[    3.362175 ]  ? w6692_init+0x38/0x38
[    3.362175 ]  nj_init+0x36/0x38
[    3.362175 ]  do_one_initcall+0x7f/0x3d0
[    3.362175 ]  ? rdinit_setup+0x45/0x45
[    3.362175 ]  ? rcu_read_lock_sched_held+0x4f/0x80
[    3.362175 ]  kernel_init_freeable+0x2aa/0x301
[    3.362175 ]  ? rest_init+0x2c0/0x2c0
[    3.362175 ]  kernel_init+0x18/0x190
[    3.362175 ]  ? rest_init+0x2c0/0x2c0
[    3.362175 ]  ? rest_init+0x2c0/0x2c0
[    3.362175 ]  ret_from_fork+0x1f/0x30
[    3.362175 ] Dumping ftrace buffer:
[    3.362175 ]    (ftrace buffer empty)
[    3.362175 ] Kernel Offset: disabled
[    3.362175 ] Rebooting in 1 seconds..

Reported-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit e072b267

 ]

This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Link: https://lore.kernel.org/r/1620789145-14936-1-git-send-email-zou_wei@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 8ab78863

 ]

The function rawsock_create() calls a privileged function sk_alloc(), which requires a ns-aware check to check net->user_ns, i.e., ns_capable(). However, the original code checks the init_user_ns using capable(). So we replace the capable() with ns_capable().

Signed-off-by: Jeimon <jjjinmeng.zhou@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 591a22c1 upstream.

Commit bfb819ea

 ("proc: Check /proc/$pid/attr/ writes against file opener")
tried to make sure that there could not be a confusion between the opener of
a /proc/$pid/attr/ file and the writer. It used struct cred to make sure
the privileges didn't change. However, there were existing cases where a more
privileged thread was passing the opened fd to a differently privileged thread
(during container setup). Instead, use mm_struct to track whether the opener
and writer are still the same process. (This is what several other proc files
already do, though for different reasons.)

Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
Reported-by: Andrea Righi <andrea.righi@canonical.com>
Tested-by: Andrea Righi <andrea.righi@canonical.com>
Fixes: bfb819ea

 ("proc: Check /proc/$pid/attr/ writes against file opener")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Link: https://lore.kernel.org/r/20210608175930.477274100@linuxfoundation.org
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Jason Self <jason@bluehome.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The commit referenced below was incomplete: It merely affected what
would get written to the vdev-<N> xenstore node. The guest would still
find the function at the original function number as long as
__xen_pcibk_get_pci_dev() wouldn't be in sync. The same goes for AER wrt
__xen_pcibk_get_pcifront_dev().

Undo overriding the function to zero and instead make sure that VFs at
function zero remain alone in their slot. This has the added benefit of
improving overall capacity, considering that there's only a total of 32
slots available right now (PCI segment and bus can both only ever be
zero at present).

This is upstream commit 4ba50e7c.

Fixes: 8a5248fe

 ("xen PV passthru: assign SR-IOV virtual functions to 
separate virtual slots")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/8def783b-404c-3452-196d-3f3fd4d72c9e@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 60588bfa upstream.

select_idle_cpu() will scan the LLC domain for idle CPUs,
it's always expensive. so the next commit :

	1ad3aaf3 ("sched/core: Implement new approach to scale select_idle_cpu()")

introduces a way to limit how many CPUs we scan.

But it consume some CPUs out of 'nr' that are not allowed
for the task and thus waste our attempts. The function
always return nr_cpumask_bits, and we can't find a CPU
which our task is allowed to run.

Cpumask may be too big, similar to select_idle_core(), use
per_cpu_ptr 'select_idle_mask' to prevent stack overflow.

Fixes: 1ad3aaf3

 ("sched/core: Implement new approach to scale select_idle_cpu()")
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20191213024530.28052-1-cj.chengjian@huawei.com
Signed-off-by: Yang Wei <yang.wei@linux.alibaba.com>
Tested-by: Yang Wei <yang.wei@linux.alibaba.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0884335a upstream.

Drop bits 63:32 on loads/stores to/from DRs and CRs when the vCPU is not
in 64-bit mode.  The APM states bits 63:32 are dropped for both DRs and
CRs:

  In 64-bit mode, the operand size is fixed at 64 bits without the need
  for a REX prefix. In non-64-bit mode, the operand size is fixed at 32
  bits and the upper 32 bits of the destination are forced to 0.

Fixes: 7ff76d58 ("KVM: SVM: enhance MOV CR intercept handler")
Fixes: cae3797a

 ("KVM: SVM: enhance mov DR intercept handler")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210422022128.3464144-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[sudip: manual backport to old file]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 1d86859f

 upstream.

The dev_port is meant to distinguish the network ports belonging to
the same PCI function.  Our devices only have one network port
associated with each PCI function and so we should not set it for
correctness.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a7036191 upstream.

In 801c6058

 ("bpf: Fix leakage of uninitialized bpf stack under
speculation") we replaced masking logic with direct loads of immediates
if the register is a known constant. Given in this case we do not apply
any masking, there is also no reason for the operation to be truncated
under the speculative domain.

Therefore, there is also zero reason for the verifier to branch-off and
simulate this case, it only needs to do it for unknown but bounded scalars.
As a side-effect, this also enables few test cases that were previously
rejected due to simulation under zero truncation.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Piotr Krysiuk <piotras@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit bb01a1bb upstream.

Masking direction as indicated via mask_to_left is considered to be
calculated once and then used to derive pointer limits. Thus, this
needs to be placed into bpf_sanitize_info instead so we can pass it
to sanitize_ptr_alu() call after the pointer move. Piotr noticed a
corner case where the off reg causes masking direction change which
then results in an incorrect final aux->alu_limit.

Fixes: 7fedb63a

 ("bpf: Tighten speculative pointer arithmetic mask")
Reported-by: Piotr Krysiuk <piotras@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Piotr Krysiuk <piotras@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 3d0220f6

 upstream.

Add a container structure struct bpf_sanitize_info which holds
the current aux info, and update call-sites to sanitize_ptr_alu()
to pass it in. This is needed for passing in additional state
later on.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Piotr Krysiuk <piotras@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 801c6058 upstream.

The current implemented mechanisms to mitigate data disclosure under
speculation mainly address stack and map value oob access from the
speculative domain. However, Piotr discovered that uninitialized BPF
stack is not protected yet, and thus old data from the kernel stack,
potentially including addresses of kernel structures, could still be
extracted from that 512 bytes large window. The BPF stack is special
compared to map values since it's not zero initialized for every
program invocation, whereas map values /are/ zero initialized upon
their initial allocation and thus cannot leak any prior data in either
domain. In the non-speculative domain, the verifier ensures that every
stack slot read must have a prior stack slot write by the BPF program
to avoid such data leaking issue.

However, this is not enough: for example, when the pointer arithmetic
operation moves the stack pointer from the last valid stack offset to
the first valid offset, the sanitation logic allows for any intermediate
offsets during speculative execution, which could then be used to
extract any restricted stack content via side-channel.

Given for unprivileged stack pointer arithmetic the use of unknown
but bounded scalars is generally forbidden, we can simply turn the
register-based arithmetic operation into an immediate-based arithmetic
operation without the need for masking. This also gives the benefit
of reducing the needed instructions for the operation. Given after
the work in 7fedb63a

 ("bpf: Tighten speculative pointer arithmetic
mask"), the aux->alu_limit already holds the final immediate value for
the offset register with the known scalar. Thus, a simple mov of the
immediate to AX register with using AX as the source for the original
instruction is sufficient and possible now in this case.

Reported-by: Piotr Krysiuk <piotras@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Piotr Krysiuk <piotras@gmail.com>
Reviewed-by: Piotr Krysiuk <piotras@gmail.com>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
[fllinden@amazon.com: fixed minor 4.14 conflict because of renamed function]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 31e95b61 upstream.

mostly revert the previous workaround and make
'dubious pointer arithmetic' test useful again.
Use (ptr - ptr) << const instead of ptr << const to generate large scalar.
The rest stays as before commit 2b36047e.

Fixes: 2b36047e

 ("selftests/bpf: fix test_align")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
[fllinden@amazon.com: adjust for 4.14 (no liveness of regs in output)]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 2b36047e upstream.

since commit 82abbf8d the verifier rejects the bit-wise
arithmetic on pointers earlier.
The test 'dubious pointer arithmetic' now has less output to match on.
Adjust it.

Fixes: 82abbf8d

 ("bpf: do not allow root to mangle valid pointers")
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit dd066823 upstream.

Subtraction of pointers was accidentally allowed for unpriv programs
by commit 82abbf8d. Revert that part of commit.

Fixes: 82abbf8d

 ("bpf: do not allow root to mangle valid pointers")
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
[fllinden@amazon.com: backport to 4.14]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 82abbf8d upstream.

Do not allow root to convert valid pointers into unknown scalars.
In particular disallow:
 ptr &= reg
 ptr <<= reg
 ptr += ptr
and explicitly allow:
 ptr -= ptr
since pkt_end - pkt == length

1.
This minimizes amount of address leaks root can do.
In the future may need to further tighten the leaks with kptr_restrict.

2.
If program has such pointer math it's likely a user mistake and
when verifier complains about it right away instead of many instructions
later on invalid memory access it's easier for users to fix their progs.

3.
when register holding a pointer cannot change to scalar it allows JITs to
optimize better. Like 32-bit archs could use single register for pointers
instead of a pair required to hold 64-bit scalars.

4.
reduces architecture dependent behavior. Since code:
r1 = r10;
r1 &= 0xff;
if (r1 ...)
will behave differently arm64 vs x64 and offloaded vs native.

A significant chunk of ptr mangling was allowed by
commit f1174f77

 ("bpf/verifier: rework value tracking")
yet some of it was allowed even earlier.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
[fllinden@amazon.com: backport to 4.14]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d7a50913

 upstream.

Update various selftest error messages:

 * The 'Rx tried to sub from different maps, paths, or prohibited types'
   is reworked into more specific/differentiated error messages for better
   guidance.

 * The change into 'value -4294967168 makes map_value pointer be out of
   bounds' is due to moving the mixed bounds check into the speculation
   handling and thus occuring slightly later than above mentioned sanity
   check.

 * The change into 'math between map_value pointer and register with
   unbounded min value' is similarly due to register sanity check coming
   before the mixed bounds check.

 * The case of 'map access: known scalar += value_ptr from different maps'
   now loads fine given masks are the same from the different paths (despite
   max map value size being different).

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
[fllinden@amazon.com - 4.14 backport, account for split test_verifier and
different / missing tests]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 7fedb63a

 upstream.

This work tightens the offset mask we use for unprivileged pointer arithmetic
in order to mitigate a corner case reported by Piotr and Benedict where in
the speculative domain it is possible to advance, for example, the map value
pointer by up to value_size-1 out-of-bounds in order to leak kernel memory
via side-channel to user space.

Before this change, the computed ptr_limit for retrieve_ptr_limit() helper
represents largest valid distance when moving pointer to the right or left
which is then fed as aux->alu_limit to generate masking instructions against
the offset register. After the change, the derived aux->alu_limit represents
the largest potential value of the offset register which we mask against which
is just a narrower subset of the former limit.

For minimal complexity, we call sanitize_ptr_alu() from 2 observation points
in adjust_ptr_min_max_vals(), that is, before and after the simulated alu
operation. In the first step, we retieve the alu_state and alu_limit before
the operation as well as we branch-off a verifier path and push it to the
verification stack as we did before which checks the dst_reg under truncation,
in other words, when the speculative domain would attempt to move the pointer
out-of-bounds.

In the second step, we retrieve the new alu_limit and calculate the absolute
distance between both. Moreover, we commit the alu_state and final alu_limit
via update_alu_sanitation_state() to the env's instruction aux data, and bail
out from there if there is a mismatch due to coming from different verification
paths with different states.

Reported-by: Piotr Krysiuk <piotras@gmail.com>
Reported-by: Benedict Schlueter <benedict.schlueter@rub.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Benedict Schlueter <benedict.schlueter@rub.de>
[fllinden@amazon.com: backported to 4.14]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f5288193

 upstream.

Add a small sanitize_needed() helper function and move sanitize_val_alu()
out of the main opcode switch. In upcoming work, we'll move sanitize_ptr_alu()
as well out of its opcode switch so this helps to streamline both.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
[fllinden@amazon.com: backported to 4.14]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 073815b7

 upstream.

Move the bounds check in adjust_ptr_min_max_vals() into a small helper named
sanitize_check_bounds() in order to simplify the former a bit.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
[fllinden@amazon.com: backport to 4.14]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a6aaece0

 upstream.

Consolidate all error handling and provide more user-friendly error messages
from sanitize_ptr_alu() and sanitize_val_alu().

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
[fllinden@amazon.com: backport to 4.14]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit b658bbb8

 upstream.

Small refactor with no semantic changes in order to consolidate the max
ptr_limit boundary check.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 24c109bb upstream.

The mixed signed bounds check really belongs into retrieve_ptr_limit()
instead of outside of it in adjust_ptr_min_max_vals(). The reason is
that this check is not tied to PTR_TO_MAP_VALUE only, but to all pointer
types that we handle in retrieve_ptr_limit() and given errors from the latter
propagate back to adjust_ptr_min_max_vals() and lead to rejection of the
program, it's a better place to reside to avoid anything slipping through
for future types. The reason why we must reject such off_reg is that we
otherwise would not be able to derive a mask, see details in 9d7eceed


("bpf: restrict unknown scalars of mixed signed bounds for unprivileged").

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
[fllinden@amazon.com: backport to 4.14]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 6f55b2f2

 upstream.

Small refactor to drag off_reg into sanitize_ptr_alu(), so we later on can
use off_reg for generalizing some of the checks for all pointer types.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
[fllinden@amazon.com: fix minor contextual conflict for 4.14]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0a13e353

 upstream.

Fix up test_verifier error messages for the case where the original error
message changed, or for the case where pointer alu errors differ between
privileged and unprivileged tests. Also, add alternative tests for keeping
coverage of the original verifier rejection error message (fp alu), and
newly reject map_ptr += rX where rX == 0 given we now forbid alu on these
types for unprivileged. All test_verifier cases pass after the change. The
test case fixups were kept separate to ease backporting of core changes.

Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
[fllinden@amazon.com: backport to 4.14, skipping non-existent tests]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit d84cf06e ]

The userfaultfd hugetlb tests cause a resv_huge_pages underflow.  This
happens when hugetlb_mcopy_atomic_pte() is called with !is_continue on
an index for which we already have a page in the cache.  When this
happens, we allocate a second page, double consuming the reservation,
and then fail to insert the page into the cache and return -EEXIST.

To fix this, we first check if there is a page in the cache which
already consumed the reservation, and return -EEXIST immediately if so.

There is still a rare condition where we fail to copy the page contents
AND race with a call for hugetlb_no_page() for this index and again we
will underflow resv_huge_pages.  That is fixed in a more complicated
patch not targeted for -stable.

Test:

  Hacked the code locally such that resv_huge_pages underflows produce a
  warning, then:

  ./tools/testing/selftests/vm/userfaultfd hugetlb_shared 10
	2 /tmp/kokonut_test/huge/userfaultfd_test && echo test success
  ./tools/testing/selftests/vm/userfaultfd hugetlb 10
	2 /tmp/kokonut_test/huge/userfaultfd_test && echo test success

Both tests succeed and produce no warnings.  After the test runs number
of free/resv hugepages is correct.

[mike.kravetz@oracle.com: changelog fixes]

Link: https://lkml.kernel.org/r/20210528004649.85298-1-almasrymina@google.com
Fixes: 8fb5debc

 ("userfaultfd: hugetlbfs: add hugetlb_mcopy_atomic_pte for userfaultfd support")
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Peter Xu <peterx@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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 011b28ac

 upstream.

This function has the following pattern

	while (1) {
		ret = whatever();
		if (ret)
			goto out;
	}
	ret = 0
out:
	return ret;

However several places in this while loop we simply break; when there's
a problem, thus clearing the return value, and in one case we do a
return -EIO, and leak the memory for the path.

Fix this by re-arranging the loop to deal with ret == 1 coming from
btrfs_search_slot, and then simply delete the

	ret = 0;
out:

bit so everybody can break if there is an error, which will allow for
proper error handling to occur.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.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>