linux-stable.git/drivers/pci/hotplug, branch v3.16.78 Linux kernel stable tree PCI: pciehp: Fix unprotected list iteration in IRQ handler 2018-12-16T22:08:19+00:00 Lukas Wunner lukas@wunner.de 2018-07-19T22:27:34+00:00 c28c5c78a887306c8d7cbe863766790bbfb13b2f commit 1204e35bedf4e5015cda559ed8c84789a6dae24e upstream. Commit b440bde74f04 ("PCI: Add pci_ignore_hotplug() to ignore hotplug events for a device") iterates over the devices on a hotplug port's subordinate bus in pciehp's IRQ handler without acquiring pci_bus_sem. It is thus possible for a user to cause a crash by concurrently manipulating the device list, e.g. by disabling slot power via sysfs on a different CPU or by initiating a remove/rescan via sysfs. This can't be fixed by acquiring pci_bus_sem because it may sleep. The simplest fix is to avoid the list iteration altogether and just check the ignore_hotplug flag on the port itself. This works because pci_ignore_hotplug() sets the flag both on the device as well as on its parent bridge. We do lose the ability to print the name of the device blocking hotplug in the debug message, but that's probably bearable. Fixes: b440bde74f04 ("PCI: Add pci_ignore_hotplug() to ignore hotplug events for a device") Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> [bwh: Backported to 3.16: s/events/intr_loc/] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 1204e35bedf4e5015cda559ed8c84789a6dae24e upstream.

Commit b440bde74f04 ("PCI: Add pci_ignore_hotplug() to ignore hotplug
events for a device") iterates over the devices on a hotplug port's
subordinate bus in pciehp's IRQ handler without acquiring pci_bus_sem.
It is thus possible for a user to cause a crash by concurrently
manipulating the device list, e.g. by disabling slot power via sysfs
on a different CPU or by initiating a remove/rescan via sysfs.

This can't be fixed by acquiring pci_bus_sem because it may sleep.
The simplest fix is to avoid the list iteration altogether and just
check the ignore_hotplug flag on the port itself.  This works because
pci_ignore_hotplug() sets the flag both on the device as well as on its
parent bridge.

We do lose the ability to print the name of the device blocking hotplug
in the debug message, but that's probably bearable.

Fixes: b440bde74f04 ("PCI: Add pci_ignore_hotplug() to ignore hotplug events for a device")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
[bwh: Backported to 3.16: s/events/intr_loc/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
PCI: pciehp: Fix use-after-free on unplug 2018-12-16T22:08:19+00:00 Lukas Wunner lukas@wunner.de 2018-07-19T22:27:32+00:00 848daaa8493f7501095d7099715d299a84d4e443 commit 281e878eab191cce4259abbbf1a0322e3adae02c upstream. When pciehp is unbound (e.g. on unplug of a Thunderbolt device), the hotplug_slot struct is deregistered and thus freed before freeing the IRQ. The IRQ handler and the work items it schedules print the slot name referenced from the freed structure in various informational and debug log messages, each time resulting in a quadruple dereference of freed pointers (hotplug_slot -> pci_slot -> kobject -> name). At best the slot name is logged as "(null)", at worst kernel memory is exposed in logs or the driver crashes: pciehp 0000:10:00.0:pcie204: Slot((null)): Card not present An attacker may provoke the bug by unplugging multiple devices on a Thunderbolt daisy chain at once. Unplugging can also be simulated by powering down slots via sysfs. The bug is particularly easy to trigger in poll mode. It has been present since the driver's introduction in 2004: https://git.kernel.org/tglx/history/c/c16b4b14d980 Fix by rearranging teardown such that the IRQ is freed first. Run the work items queued by the IRQ handler to completion before freeing the hotplug_slot struct by draining the work queue from the ->release_slot callback which is invoked by pci_hp_deregister(). Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 281e878eab191cce4259abbbf1a0322e3adae02c upstream.

When pciehp is unbound (e.g. on unplug of a Thunderbolt device), the
hotplug_slot struct is deregistered and thus freed before freeing the
IRQ.  The IRQ handler and the work items it schedules print the slot
name referenced from the freed structure in various informational and
debug log messages, each time resulting in a quadruple dereference of
freed pointers (hotplug_slot -> pci_slot -> kobject -> name).

At best the slot name is logged as "(null)", at worst kernel memory is
exposed in logs or the driver crashes:

  pciehp 0000:10:00.0:pcie204: Slot((null)): Card not present

An attacker may provoke the bug by unplugging multiple devices on a
Thunderbolt daisy chain at once.  Unplugging can also be simulated by
powering down slots via sysfs.  The bug is particularly easy to trigger
in poll mode.

It has been present since the driver's introduction in 2004:
https://git.kernel.org/tglx/history/c/c16b4b14d980

Fix by rearranging teardown such that the IRQ is freed first.  Run the
work items queued by the IRQ handler to completion before freeing the
hotplug_slot struct by draining the work queue from the ->release_slot
callback which is invoked by pci_hp_deregister().

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
PCI: hotplug: Don't leak pci_slot on registration failure 2018-12-16T22:08:18+00:00 Lukas Wunner lukas@wunner.de 2018-07-19T22:27:31+00:00 1fa3ed6898b12091e3dffaf591031031f9fec048 commit 4ce6435820d1f1cc2c2788e232735eb244bcc8a3 upstream. If addition of sysfs files fails on registration of a hotplug slot, the struct pci_slot as well as the entry in the slot_list is leaked. The issue has been present since the hotplug core was introduced in 2002: https://git.kernel.org/tglx/history/c/a8a2069f432c Perhaps the idea was that even though sysfs addition fails, the slot should still be usable. But that's not how drivers use the interface, they abort probe if a non-zero value is returned. Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 4ce6435820d1f1cc2c2788e232735eb244bcc8a3 upstream.

If addition of sysfs files fails on registration of a hotplug slot, the
struct pci_slot as well as the entry in the slot_list is leaked.  The
issue has been present since the hotplug core was introduced in 2002:
https://git.kernel.org/tglx/history/c/a8a2069f432c

Perhaps the idea was that even though sysfs addition fails, the slot
should still be usable.  But that's not how drivers use the interface,
they abort probe if a non-zero value is returned.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
PCI: shpchp: Fix AMD POGO identification 2018-11-20T18:05:09+00:00 Bjorn Helgaas bhelgaas@google.com 2018-05-30T19:06:42+00:00 d67598ec188e82e056598f1da37610357981eed6 commit bed4e9cfab93a0f3d0144cb919820e6d5c40b8b1 upstream. The fix for an AMD POGO erratum related to SHPC incorrectly identified the device. The workaround should be applied only for AMD POGO devices, but it was instead applied to: - all AMD bridges, and - all devices from any vendor with device ID 0x7458 Fixes: 53044f357448 ("[PATCH] PCI Hotplug: shpchp: AMD POGO errata fix") Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit bed4e9cfab93a0f3d0144cb919820e6d5c40b8b1 upstream.

The fix for an AMD POGO erratum related to SHPC incorrectly identified the
device.  The workaround should be applied only for AMD POGO devices, but it
was instead applied to:

  - all AMD bridges, and
  - all devices from any vendor with device ID 0x7458

Fixes: 53044f357448 ("[PATCH] PCI Hotplug: shpchp: AMD POGO errata fix")
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
PCI: pciehp: Clear Presence Detect and Data Link Layer Status Changed on resume 2018-11-20T18:05:01+00:00 Mika Westerberg mika.westerberg@linux.intel.com 2018-05-23T22:14:39+00:00 1474ad318dbe0d8c18e663b88845740c468eb31c commit 13c65840feab8109194f9490c9870587173cb29d upstream. After a suspend/resume cycle the Presence Detect or Data Link Layer Status Changed bits might be set. If we don't clear them those events will not fire anymore and nothing happens for instance when a device is now hot-unplugged. Fix this by clearing those bits in a newly introduced function pcie_reenable_notification(). This should be fine because immediately after, we check if the adapter is still present by reading directly from the status register. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 13c65840feab8109194f9490c9870587173cb29d upstream.

After a suspend/resume cycle the Presence Detect or Data Link Layer Status
Changed bits might be set.  If we don't clear them those events will not
fire anymore and nothing happens for instance when a device is now
hot-unplugged.

Fix this by clearing those bits in a newly introduced function
pcie_reenable_notification().  This should be fine because immediately
after, we check if the adapter is still present by reading directly from
the status register.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
PCI: ibmphp: Fix use-before-set in get_max_bus_speed() 2018-11-20T18:04:49+00:00 Dan Carpenter dan.carpenter@oracle.com 2018-04-19T10:05:49+00:00 9447dabf5ea263c3a34a8d7c9f4e7b56259a558f commit 4051f5ebb11c6ef4b0d3eac2fbbd187c070656c5 upstream. The "rc" variable is only initialized on the error path. The caller doesn't check the return but, if "rc" is non-zero, then this function is basically a no-op. Fixes: 3749c51ac6c1 ("PCI: Make current and maximum bus speeds part of the PCI core") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 4051f5ebb11c6ef4b0d3eac2fbbd187c070656c5 upstream.

The "rc" variable is only initialized on the error path.  The caller
doesn't check the return but, if "rc" is non-zero, then this function is
basically a no-op.

Fixes: 3749c51ac6c1 ("PCI: Make current and maximum bus speeds part of the PCI core")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ACPI / hotplug / PCI: Check presence of slot itself in get_slot_status() 2018-10-21T07:44:58+00:00 Mika Westerberg mika.westerberg@linux.intel.com 2018-02-12T10:55:23+00:00 6e0e1d42acc4cdf87a4b3ae67dd6a741bccc6919 commit 13d3047c81505cc0fb9bdae7810676e70523c8bf upstream. Mike Lothian reported that plugging in a USB-C device does not work properly in his Dell Alienware system. This system has an Intel Alpine Ridge Thunderbolt controller providing USB-C functionality. In these systems the USB controller (xHCI) is hotplugged whenever a device is connected to the port using ACPI-based hotplug. The ACPI description of the root port in question is as follows: Device (RP01) { Name (_ADR, 0x001C0000) Device (PXSX) { Name (_ADR, 0x02) Method (_RMV, 0, NotSerialized) { // ... } } Here _ADR 0x02 means device 0, function 2 on the bus under root port (RP01) but that seems to be incorrect because device 0 is the upstream port of the Alpine Ridge PCIe switch and it has no functions other than 0 (the bridge itself). When we get ACPI Notify() to the root port resulting from connecting a USB-C device, Linux tries to read PCI_VENDOR_ID from device 0, function 2 which of course always returns 0xffffffff because there is no such function and we never find the device. In Windows this works fine. Now, since we get ACPI Notify() to the root port and not to the PXSX device we should actually start our scan from there as well and not from the non-existent PXSX device. Fix this by checking presence of the slot itself (function 0) if we fail to do that otherwise. While there use pci_bus_read_dev_vendor_id() in get_slot_status(), which is the recommended way to read Device and Vendor IDs of devices on PCI buses. Link: https://bugzilla.kernel.org/show_bug.cgi?id=198557 Reported-by: Mike Lothian <mike@fireburn.co.uk> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 13d3047c81505cc0fb9bdae7810676e70523c8bf upstream.

Mike Lothian reported that plugging in a USB-C device does not work
properly in his Dell Alienware system.  This system has an Intel Alpine
Ridge Thunderbolt controller providing USB-C functionality.  In these
systems the USB controller (xHCI) is hotplugged whenever a device is
connected to the port using ACPI-based hotplug.

The ACPI description of the root port in question is as follows:

  Device (RP01)
  {
      Name (_ADR, 0x001C0000)

      Device (PXSX)
      {
          Name (_ADR, 0x02)

          Method (_RMV, 0, NotSerialized)
          {
              // ...
          }
      }

Here _ADR 0x02 means device 0, function 2 on the bus under root port (RP01)
but that seems to be incorrect because device 0 is the upstream port of the
Alpine Ridge PCIe switch and it has no functions other than 0 (the bridge
itself).  When we get ACPI Notify() to the root port resulting from
connecting a USB-C device, Linux tries to read PCI_VENDOR_ID from device 0,
function 2 which of course always returns 0xffffffff because there is no
such function and we never find the device.

In Windows this works fine.

Now, since we get ACPI Notify() to the root port and not to the PXSX device
we should actually start our scan from there as well and not from the
non-existent PXSX device.  Fix this by checking presence of the slot itself
(function 0) if we fail to do that otherwise.

While there use pci_bus_read_dev_vendor_id() in get_slot_status(), which is
the recommended way to read Device and Vendor IDs of devices on PCI buses.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=198557
Reported-by: Mike Lothian <mike@fireburn.co.uk>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
PCI: shpchp: Enable bridge bus mastering if MSI is enabled 2017-11-26T13:50:16+00:00 Aleksandr Bezzubikov zuban32s@gmail.com 2017-07-18T14:12:25+00:00 47cdbb45c490dbbe2aabec10b9b6583bf52172a7 commit 48b79a14505349a29b3e20f03619ada9b33c4b17 upstream. An SHPC may generate MSIs to notify software about slot or controller events (SHPC spec r1.0, sec 4.7). A PCI device can only generate an MSI if it has bus mastering enabled. Enable bus mastering if the bridge contains an SHPC that uses MSI for event notifications. Signed-off-by: Aleksandr Bezzubikov <zuban32s@gmail.com> [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Marcel Apfelbaum <marcel@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 48b79a14505349a29b3e20f03619ada9b33c4b17 upstream.

An SHPC may generate MSIs to notify software about slot or controller
events (SHPC spec r1.0, sec 4.7).  A PCI device can only generate an MSI if
it has bus mastering enabled.

Enable bus mastering if the bridge contains an SHPC that uses MSI for event
notifications.

Signed-off-by: Aleksandr Bezzubikov <zuban32s@gmail.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
powerpc/pci/rpadlpar: Fix device reference leaks 2017-03-16T02:26:20+00:00 Johan Hovold johan@kernel.org 2016-11-01T15:26:03+00:00 4554c6aec03bb0135cafadb68e4531e2d13b07f4 commit 99e5cde5eae78bef95bfe7c16ccda87fb070149b upstream. Make sure to drop any device reference taken by vio_find_node() when adding and removing virtual I/O slots. Fixes: 5eeb8c63a38f ("[PATCH] PCI Hotplug: rpaphp: Move VIO registration") Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 99e5cde5eae78bef95bfe7c16ccda87fb070149b upstream.

Make sure to drop any device reference taken by vio_find_node() when
adding and removing virtual I/O slots.

Fixes: 5eeb8c63a38f ("[PATCH] PCI Hotplug: rpaphp: Move VIO registration")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ACPI / PCI / hotplug: unlock in error path in acpiphp_enable_slot() 2016-02-16T19:50:02+00:00 Insu Yun wuninsu@gmail.com 2016-01-23T20:44:19+00:00 e4fa01001270fcf5fefa4a2f11d6c793a9fee7db commit 2c3033a0664dfae91e1dee7fabac10f24354b958 upstream. In acpiphp_enable_slot(), there is a missing unlock path when error occurred. It needs to be unlocked before returning an error. Signed-off-by: Insu Yun <wuninsu@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> 
commit 2c3033a0664dfae91e1dee7fabac10f24354b958 upstream.

In acpiphp_enable_slot(), there is a missing unlock path
when error occurred.  It needs to be unlocked before returning
an error.

Signed-off-by: Insu Yun <wuninsu@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>