linux-stable.git/drivers, branch v4.9.202

x86/bugs: Add ITLB_MULTIHIT bug infrastructure

2019-11-16T09:29:54+00:00

commit db4d30fbb71b47e4ecb11c4efa5d8aad4b03dfae upstream.

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

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

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

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

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

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

Signed-off-by: Vineela Tummalapalli 
Co-developed-by: Pawan Gupta 
Signed-off-by: Pawan Gupta 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Thomas Gleixner 
[bwh: Backported to 4.9:
 - No support for X86_VENDOR_HYGON, ATOM_AIRMONT_NP
 - Adjust context, indentation]
Signed-off-by: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

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

2019-11-16T09:29:43+00:00

commit 6608b45ac5ecb56f9e171252229c39580cc85f0f upstream.

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

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

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

usb: gadget: core: unmap request from DMA only if previously mapped

2019-11-16T09:29:37+00:00

commit 31fe084ffaaf8abece14f8ca28e5e3b4e2bf97b6 upstream.

In the SG case this is already handled since a non-zero
request->num_mapped_sgs is a clear indicator that dma_map_sg()
had been called. While it would be nice to do the same for the
singly mapped case by simply checking for non-zero request->dma,
it's conceivable that 0 is a valid dma_addr_t handle. Hence add
a flag 'dma_mapped' to struct usb_request and use this to
determine the need to call dma_unmap_single(). Otherwise, if a
request is not DMA mapped then the result of calling
usb_request_unmap_request() would safely be a no-op.

Signed-off-by: Jack Pham 
Signed-off-by: Felipe Balbi 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: hci_ldisc: Postpone HCI_UART_PROTO_READY bit set in hci_uart_set_proto()

2019-11-16T09:29:34+00:00

commit 56897b217a1d0a91c9920cb418d6b3fe922f590a upstream.

task A:                                task B:
hci_uart_set_proto                     flush_to_ldisc
 - p->open(hu) -> h5_open  //alloc h5  - receive_buf
 - set_bit HCI_UART_PROTO_READY         - tty_port_default_receive_buf
 - hci_uart_register_dev                 - tty_ldisc_receive_buf
                                          - hci_uart_tty_receive
				           - test_bit HCI_UART_PROTO_READY
				            - h5_recv
 - clear_bit HCI_UART_PROTO_READY             while() {
 - p->open(hu) -> h5_close //free h5
				              - h5_rx_3wire_hdr
				               - h5_reset()  //use-after-free
                                              }

It could use ioctl to set hci uart proto, but there is
a use-after-free issue when hci_uart_register_dev() fail in
hci_uart_set_proto(), see stack above, fix this by setting
HCI_UART_PROTO_READY bit only when hci_uart_register_dev()
return success.

Reported-by: syzbot+899a33dc0fa0dbaf06a6@syzkaller.appspotmail.com
Signed-off-by: Kefeng Wang 
Reviewed-by: Jeremy Cline 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Greg Kroah-Hartman

drm/i915/cmdparser: Fix jump whitelist clearing

2019-11-12T18:16:24+00:00

commit ea0b163b13ffc52818c079adb00d55e227a6da6f upstream.

When a jump_whitelist bitmap is reused, it needs to be cleared.
Currently this is done with memset() and the size calculation assumes
bitmaps are made of 32-bit words, not longs.  So on 64-bit
architectures, only the first half of the bitmap is cleared.

If some whitelist bits are carried over between successive batches
submitted on the same context, this will presumably allow embedding
the rogue instructions that we're trying to reject.

Use bitmap_zero() instead, which gets the calculation right.

Fixes: f8c08d8faee5 ("drm/i915/cmdparser: Add support for backward jumps")
Signed-off-by: Ben Hutchings 
Signed-off-by: Jon Bloomfield 
Signed-off-by: Greg Kroah-Hartman

drm/i915/gen8+: Add RC6 CTX corruption WA

2019-11-12T18:16:24+00:00

commit 7e34f4e4aad3fd34c02b294a3cf2321adf5b4438 upstream.

In some circumstances the RC6 context can get corrupted. We can detect
this and take the required action, that is disable RC6 and runtime PM.
The HW recovers from the corrupted state after a system suspend/resume
cycle, so detect the recovery and re-enable RC6 and runtime PM.

v2: rebase (Mika)
v3:
- Move intel_suspend_gt_powersave() to the end of the GEM suspend
  sequence.
- Add commit message.
v4:
- Rebased on intel_uncore_forcewake_put(i915->uncore, ...) API
  change.
v5:
- Rebased on latest upstream gt_pm refactoring.

Signed-off-by: Imre Deak 
Signed-off-by: Mika Kuoppala 
Signed-off-by: Greg Kroah-Hartman

drm/i915: Lower RM timeout to avoid DSI hard hangs

2019-11-12T18:16:23+00:00

commit 1d85a299c4db57c55e0229615132c964d17aa765 upstream.

In BXT/APL, device 2 MMIO reads from MIPI controller requires its PLL
to be turned ON. When MIPI PLL is turned off (MIPI Display is not
active or connected), and someone (host or GT engine) tries to read
MIPI registers, it causes hard hang. This is a hardware restriction
or limitation.

Driver by itself doesn't read MIPI registers when MIPI display is off.
But any userspace application can submit unprivileged batch buffer for
execution. In that batch buffer there can be mmio reads. And these
reads are allowed even for unprivileged applications. If these
register reads are for MIPI DSI controller and MIPI display is not
active during that time, then the MMIO read operation causes system
hard hang and only way to recover is hard reboot. A genuine
process/application won't submit batch buffer like this and doesn't
cause any issue. But on a compromised system, a malign userspace
process/app can generate such batch buffer and can trigger system
hard hang (denial of service attack).

The fix is to lower the internal MMIO timeout value to an optimum
value of 950us as recommended by hardware team. If the timeout is
beyond 1ms (which will hit for any value we choose if MMIO READ on a
DSI specific register is performed without PLL ON), it causes the
system hang. But if the timeout value is lower than it will be below
the threshold (even if timeout happens) and system will not get into
a hung state. This will avoid a system hang without losing any
programming or GT interrupts, taking the worst case of lowest CDCLK
frequency and early DC5 abort into account.

Signed-off-by: Uma Shankar 
Reviewed-by: Jon Bloomfield 
Signed-off-by: Greg Kroah-Hartman

drm/i915/cmdparser: Ignore Length operands during command matching

2019-11-12T18:16:23+00:00

commit 926abff21a8f29ef159a3ac893b05c6e50e043c3 upstream.

Some of the gen instruction macros (e.g. MI_DISPLAY_FLIP) have the
length directly encoded in them. Since these are used directly in
the tables, the Length becomes part of the comparison used for
matching during parsing. Thus, if the cmd being parsed has a
different length to that in the table, it is not matched and the
cmd is accepted via the default variable length path.

Fix by masking out everything except the Opcode in the cmd tables

Cc: Tony Luck 
Cc: Dave Airlie 
Cc: Takashi Iwai 
Cc: Tyler Hicks 
Signed-off-by: Jon Bloomfield 
Reviewed-by: Chris Wilson 
Signed-off-by: Greg Kroah-Hartman

drm/i915/cmdparser: Add support for backward jumps

2019-11-12T18:16:23+00:00

commit f8c08d8faee5567803c8c533865296ca30286bbf upstream.

To keep things manageable, the pre-gen9 cmdparser does not
attempt to track any form of nested BB_START's. This did not
prevent usermode from using nested starts, or even chained
batches because the cmdparser is not strictly enforced pre gen9.

Instead, the existence of a nested BB_START would cause the batch
to be emitted in insecure mode, and any privileged capabilities
would not be available.

For Gen9, the cmdparser becomes mandatory (for BCS at least), and
so not providing any form of nested BB_START support becomes
overly restrictive. Any such batch will simply not run.

We make heavy use of backward jumps in igt, and it is much easier
to add support for this restricted subset of nested jumps, than to
rewrite the whole of our test suite to avoid them.

Add the required logic to support limited backward jumps, to
instructions that have already been validated by the parser.

Note that it's not sufficient to simply approve any BB_START
that jumps backwards in the buffer because this would allow an
attacker to embed a rogue instruction sequence within the
operand words of a harmless instruction (say LRI) and jump to
that.

We introduce a bit array to track every instr offset successfully
validated, and test the target of BB_START against this. If the
target offset hits, it is re-written to the same offset in the
shadow buffer and the BB_START cmd is allowed.

Note: This patch deliberately ignores checkpatch issues in the
cmdtables, in order to match the style of the surrounding code.
We'll correct the entire file in one go in a later patch.

v2: set dispatch secure late (Mika)
v3: rebase (Mika)
v4: Clear whitelist on each parse
Minor review updates (Chris)
v5: Correct backward jump batching
v6: fix compilation error due to struct eb shuffle (Mika)

Cc: Tony Luck 
Cc: Dave Airlie 
Cc: Takashi Iwai 
Cc: Tyler Hicks 
Signed-off-by: Jon Bloomfield 
Signed-off-by: Mika Kuoppala 
Reviewed-by: Chris Wilson 
Signed-off-by: Greg Kroah-Hartman

drm/i915/cmdparser: Use explicit goto for error paths

2019-11-12T18:16:22+00:00

commit 0546a29cd884fb8184731c79ab008927ca8859d0 upstream.

In the next patch we will be adding a second valid
termination condition which will require a small
amount of refactoring to share logic with the BB_END
case.

Refactor all error conditions to jump to a dedicated
exit path, with 'break' reserved only for a successful
parse.

Signed-off-by: Jon Bloomfield 
Cc: Tony Luck 
Cc: Dave Airlie 
Cc: Takashi Iwai 
Cc: Tyler Hicks 
Signed-off-by: Mika Kuoppala 
Reviewed-by: Chris Wilson 
Signed-off-by: Greg Kroah-Hartman