linux-stable.git/include, branch v4.14.136

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

2019-08-04T07:32:03+00:00

commit 16d51a590a8ce3befb1308e0e7ab77f3b661af33 upstream.

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

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

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

Signed-off-by: Jann Horn 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Petr Mladek 
Cc: Sergey Senozhatsky 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Fixes: 82727018b0d3 ("sched/numa: Call task_numa_free() from do_execve()")
Link: https://lkml.kernel.org/r/20190716152047.14424-1-jannh@google.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

iommu/iova: Fix compilation error with !CONFIG_IOMMU_IOVA

2019-08-04T07:32:02+00:00

commit 201c1db90cd643282185a00770f12f95da330eca upstream.

The stub function for !CONFIG_IOMMU_IOVA needs to be
'static inline'.

Fixes: effa467870c76 ('iommu/vt-d: Don't queue_iova() if there is no flush queue')
Signed-off-by: Joerg Roedel 
Signed-off-by: Dmitry Safonov 
Signed-off-by: Greg Kroah-Hartman

iommu/vt-d: Don't queue_iova() if there is no flush queue

2019-08-04T07:32:02+00:00

commit effa467870c7612012885df4e246bdb8ffd8e44c upstream.

Intel VT-d driver was reworked to use common deferred flushing
implementation. Previously there was one global per-cpu flush queue,
afterwards - one per domain.

Before deferring a flush, the queue should be allocated and initialized.

Currently only domains with IOMMU_DOMAIN_DMA type initialize their flush
queue. It's probably worth to init it for static or unmanaged domains
too, but it may be arguable - I'm leaving it to iommu folks.

Prevent queuing an iova flush if the domain doesn't have a queue.
The defensive check seems to be worth to keep even if queue would be
initialized for all kinds of domains. And is easy backportable.

On 4.19.43 stable kernel it has a user-visible effect: previously for
devices in si domain there were crashes, on sata devices:

 BUG: spinlock bad magic on CPU#6, swapper/0/1
  lock: 0xffff88844f582008, .magic: 00000000, .owner: /-1, .owner_cpu: 0
 CPU: 6 PID: 1 Comm: swapper/0 Not tainted 4.19.43 #1
 Call Trace:
  
  dump_stack+0x61/0x7e
  spin_bug+0x9d/0xa3
  do_raw_spin_lock+0x22/0x8e
  _raw_spin_lock_irqsave+0x32/0x3a
  queue_iova+0x45/0x115
  intel_unmap+0x107/0x113
  intel_unmap_sg+0x6b/0x76
  __ata_qc_complete+0x7f/0x103
  ata_qc_complete+0x9b/0x26a
  ata_qc_complete_multiple+0xd0/0xe3
  ahci_handle_port_interrupt+0x3ee/0x48a
  ahci_handle_port_intr+0x73/0xa9
  ahci_single_level_irq_intr+0x40/0x60
  __handle_irq_event_percpu+0x7f/0x19a
  handle_irq_event_percpu+0x32/0x72
  handle_irq_event+0x38/0x56
  handle_edge_irq+0x102/0x121
  handle_irq+0x147/0x15c
  do_IRQ+0x66/0xf2
  common_interrupt+0xf/0xf
 RIP: 0010:__do_softirq+0x8c/0x2df

The same for usb devices that use ehci-pci:
 BUG: spinlock bad magic on CPU#0, swapper/0/1
  lock: 0xffff88844f402008, .magic: 00000000, .owner: /-1, .owner_cpu: 0
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.43 #4
 Call Trace:
  
  dump_stack+0x61/0x7e
  spin_bug+0x9d/0xa3
  do_raw_spin_lock+0x22/0x8e
  _raw_spin_lock_irqsave+0x32/0x3a
  queue_iova+0x77/0x145
  intel_unmap+0x107/0x113
  intel_unmap_page+0xe/0x10
  usb_hcd_unmap_urb_setup_for_dma+0x53/0x9d
  usb_hcd_unmap_urb_for_dma+0x17/0x100
  unmap_urb_for_dma+0x22/0x24
  __usb_hcd_giveback_urb+0x51/0xc3
  usb_giveback_urb_bh+0x97/0xde
  tasklet_action_common.isra.4+0x5f/0xa1
  tasklet_action+0x2d/0x30
  __do_softirq+0x138/0x2df
  irq_exit+0x7d/0x8b
  smp_apic_timer_interrupt+0x10f/0x151
  apic_timer_interrupt+0xf/0x20
  
 RIP: 0010:_raw_spin_unlock_irqrestore+0x17/0x39

Cc: David Woodhouse 
Cc: Joerg Roedel 
Cc: Lu Baolu 
Cc: iommu@lists.linux-foundation.org
Cc:  # 4.14+
Fixes: 13cf01744608 ("iommu/vt-d: Make use of iova deferred flushing")
Signed-off-by: Dmitry Safonov 
Reviewed-by: Lu Baolu 
Signed-off-by: Joerg Roedel 
[v4.14-port notes:
o minor conflict with untrusted IOMMU devices check under if-condition
o setup_timer() near one chunk is timer_setup() in v5.3]
Signed-off-by: Dmitry Safonov 
Signed-off-by: Greg Kroah-Hartman

VSOCK: use TCP state constants for sk_state

2019-08-04T07:31:59+00:00

commit 3b4477d2dcf2709d0be89e2a8dced3d0f4a017f2 upstream.

There are two state fields: socket->state and sock->sk_state.  The
socket->state field uses SS_UNCONNECTED, SS_CONNECTED, etc while the
sock->sk_state typically uses values that match TCP state constants
(TCP_CLOSE, TCP_ESTABLISHED).  AF_VSOCK does not follow this convention
and instead uses SS_* constants for both fields.

The sk_state field will be exposed to userspace through the vsock_diag
interface for ss(8), netstat(8), and other programs.

This patch switches sk_state to TCP state constants so that the meaning
of this field is consistent with other address families.  Not just
AF_INET and AF_INET6 use the TCP constants, AF_UNIX and others do too.

The following mapping was used to convert the code:

  SS_FREE -> TCP_CLOSE
  SS_UNCONNECTED -> TCP_CLOSE
  SS_CONNECTING -> TCP_SYN_SENT
  SS_CONNECTED -> TCP_ESTABLISHED
  SS_DISCONNECTING -> TCP_CLOSING
  VSOCK_SS_LISTEN -> TCP_LISTEN

In __vsock_create() the sk_state initialization was dropped because
sock_init_data() already initializes sk_state to TCP_CLOSE.

Signed-off-by: Stefan Hajnoczi 
Signed-off-by: David S. Miller 
[Adjusted net/vmw_vsock/hyperv_transport.c since the commit
b4562ca7925a ("hv_sock: add locking in the open/close/release code paths")
and the commit
c9d3fe9da094 ("VSOCK: fix outdated sk_state value in hvs_release()")
were backported before 3b4477d2dcf2.]
Signed-off-by: Dexuan Cui 
Signed-off-by: Greg Kroah-Hartman

access: avoid the RCU grace period for the temporary subjective credentials

2019-07-31T05:28:58+00:00

commit d7852fbd0f0423937fa287a598bfde188bb68c22 upstream.

It turns out that 'access()' (and 'faccessat()') can cause a lot of RCU
work because it installs a temporary credential that gets allocated and
freed for each system call.

The allocation and freeing overhead is mostly benign, but because
credentials can be accessed under the RCU read lock, the freeing
involves a RCU grace period.

Which is not a huge deal normally, but if you have a lot of access()
calls, this causes a fair amount of seconday damage: instead of having a
nice alloc/free patterns that hits in hot per-CPU slab caches, you have
all those delayed free's, and on big machines with hundreds of cores,
the RCU overhead can end up being enormous.

But it turns out that all of this is entirely unnecessary.  Exactly
because access() only installs the credential as the thread-local
subjective credential, the temporary cred pointer doesn't actually need
to be RCU free'd at all.  Once we're done using it, we can just free it
synchronously and avoid all the RCU overhead.

So add a 'non_rcu' flag to 'struct cred', which can be set by users that
know they only use it in non-RCU context (there are other potential
users for this).  We can make it a union with the rcu freeing list head
that we need for the RCU case, so this doesn't need any extra storage.

Note that this also makes 'get_current_cred()' clear the new non_rcu
flag, in case we have filesystems that take a long-term reference to the
cred and then expect the RCU delayed freeing afterwards.  It's not
entirely clear that this is required, but it makes for clear semantics:
the subjective cred remains non-RCU as long as you only access it
synchronously using the thread-local accessors, but you _can_ use it as
a generic cred if you want to.

It is possible that we should just remove the whole RCU markings for
->cred entirely.  Only ->real_cred is really supposed to be accessed
through RCU, and the long-term cred copies that nfs uses might want to
explicitly re-enable RCU freeing if required, rather than have
get_current_cred() do it implicitly.

But this is a "minimal semantic changes" change for the immediate
problem.

Acked-by: Peter Zijlstra (Intel) 
Acked-by: Eric Dumazet 
Acked-by: Paul E. McKenney 
Cc: Oleg Nesterov 
Cc: Jan Glauber 
Cc: Jiri Kosina 
Cc: Jayachandran Chandrasekharan Nair 
Cc: Greg KH 
Cc: Kees Cook 
Cc: David Howells 
Cc: Miklos Szeredi 
Cc: Al Viro 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

drm/crc: Only report a single overflow when a CRC fd is opened

2019-07-31T05:28:56+00:00

[ Upstream commit a012024571d98e2e4bf29a9168fb7ddc44b7ab86 ]

This reduces the amount of spam when you debug a CRC reading
program.

Signed-off-by: Maarten Lankhorst 
[mlankhorst: Change bool overflow to was_overflow (Ville)]
Reviewed-by: Ville Syrjälä 
Link: https://patchwork.freedesktop.org/patch/msgid/20180418125121.72081-1-maarten.lankhorst@linux.intel.com
Signed-off-by: Sasha Levin

jbd2: introduce jbd2_inode dirty range scoping

2019-07-31T05:28:47+00:00

commit 6ba0e7dc64a5adcda2fbe65adc466891795d639e upstream.

Currently both journal_submit_inode_data_buffers() and
journal_finish_inode_data_buffers() operate on the entire address space
of each of the inodes associated with a given journal entry.  The
consequence of this is that if we have an inode where we are constantly
appending dirty pages we can end up waiting for an indefinite amount of
time in journal_finish_inode_data_buffers() while we wait for all the
pages under writeback to be written out.

The easiest way to cause this type of workload is do just dd from
/dev/zero to a file until it fills the entire filesystem.  This can
cause journal_finish_inode_data_buffers() to wait for the duration of
the entire dd operation.

We can improve this situation by scoping each of the inode dirty ranges
associated with a given transaction.  We do this via the jbd2_inode
structure so that the scoping is contained within jbd2 and so that it
follows the lifetime and locking rules for that structure.

This allows us to limit the writeback & wait in
journal_submit_inode_data_buffers() and
journal_finish_inode_data_buffers() respectively to the dirty range for
a given struct jdb2_inode, keeping us from waiting forever if the inode
in question is still being appended to.

Signed-off-by: Ross Zwisler 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Jan Kara 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

mm: add filemap_fdatawait_range_keep_errors()

2019-07-31T05:28:47+00:00

commit aa0bfcd939c30617385ffa28682c062d78050eba upstream.

In the spirit of filemap_fdatawait_range() and
filemap_fdatawait_keep_errors(), introduce
filemap_fdatawait_range_keep_errors() which both takes a range upon
which to wait and does not clear errors from the address space.

Signed-off-by: Ross Zwisler 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Jan Kara 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

tcp: fix tcp_set_congestion_control() use from bpf hook

2019-07-31T05:28:46+00:00

[ Upstream commit 8d650cdedaabb33e85e9b7c517c0c71fcecc1de9 ]

Neal reported incorrect use of ns_capable() from bpf hook.

bpf_setsockopt(...TCP_CONGESTION...)
  -> tcp_set_congestion_control()
   -> ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)
    -> ns_capable_common()
     -> current_cred()
      -> rcu_dereference_protected(current->cred, 1)

Accessing 'current' in bpf context makes no sense, since packets
are processed from softirq context.

As Neal stated : The capability check in tcp_set_congestion_control()
was written assuming a system call context, and then was reused from
a BPF call site.

The fix is to add a new parameter to tcp_set_congestion_control(),
so that the ns_capable() call is only performed under the right
context.

Fixes: 91b5b21c7c16 ("bpf: Add support for changing congestion control")
Signed-off-by: Eric Dumazet 
Cc: Lawrence Brakmo 
Reported-by: Neal Cardwell 
Acked-by: Neal Cardwell 
Acked-by: Lawrence Brakmo 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: make skb_dst_force return true when dst is refcounted

2019-07-31T05:28:46+00:00

[ Upstream commit b60a77386b1d4868f72f6353d35dabe5fbe981f2 ]

netfilter did not expect that skb_dst_force() can cause skb to lose its
dst entry.

I got a bug report with a skb->dst NULL dereference in netfilter
output path.  The backtrace contains nf_reinject(), so the dst might have
been cleared when skb got queued to userspace.

Other users were fixed via
if (skb_dst(skb)) {
	skb_dst_force(skb);
	if (!skb_dst(skb))
		goto handle_err;
}

But I think its preferable to make the 'dst might be cleared' part
of the function explicit.

In netfilter case, skb with a null dst is expected when queueing in
prerouting hook, so drop skb for the other hooks.

v2:
 v1 of this patch returned true in case skb had no dst entry.
 Eric said:
   Say if we have two skb_dst_force() calls for some reason
   on the same skb, only the first one will return false.

 This now returns false even when skb had no dst, as per Erics
 suggestion, so callers might need to check skb_dst() first before
 skb_dst_force().

Signed-off-by: Florian Westphal 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman