Commit Graph

18 Commits (bac318743905e55ce424104cafbc8418e0672a80)

Author SHA1 Message Date
Michael Brown bac3187439 [efi] Use efi_open() for all ephemeral protocol opens
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2025-03-24 13:19:26 +00:00
Michael Brown 02ecb23d10 [efi] Get veto candidate driver name via either component name protocol
Attempt to get the veto candidate driver name from both the current
and obsolete versions of the component name protocol.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2025-03-20 15:17:08 +00:00
Michael Brown 756e3907fd [efi] Get veto candidate driver name from image handle
Allow for drivers that do not install the driver binding protocol on
the image handle by opening the component name protocol on the driver
binding's ImageHandle rather than on the driver handle itself.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2025-03-20 14:39:52 +00:00
Michael Brown be5bf0aa7a [efi] Show image address range in veto debug messages
When hunting down a misbehaving OEM driver to add it to the veto list,
it can be very useful to know the address ranges used by each driver.
Add this information to the verbose debug messages.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2025-03-20 14:30:34 +00:00
Michael Brown cb95b5b378 [efi] Veto the Dhcp6Dxe driver on all platforms
The reference implementation of Dhcp6Dxe in EDK2 has a fatal flaw: the
code in EfiDhcp6Stop() will poll the network in a tight loop until
either a response is received or a timer tick (at TPL_CALLBACK)
occurs.  When EfiDhcp6Stop() is called at TPL_CALLBACK or higher, this
will result in an endless loop and an apparently frozen system.

Since this is the reference implementation of Dhcp6Dxe, it is likely
that almost all platforms have the same problem.

Fix by vetoing the broken driver.  If the upstream driver is ever
fixed and a new version number issued, then we could plausibly test
against the version number exposed via the driver binding protocol.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-04-16 14:19:01 +01:00
Michael Brown ae435cb4cc [efi] Process veto objects in reverse order of enumeration
While not guaranteed by the UEFI specification, the enumeration of
handles, protocols, and openers will generally return results in order
of creation.  Processing these objects in reverse order (as is already
done when calling DisconnectController() on the list of all handles)
will generally therefore perform the forcible uninstallation
operations in reverse order of object creation, which minimises the
number of implicit operations performed (e.g. when disconnecting a
controller that itself still has existent child controllers).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-06-23 16:51:10 +01:00
Michael Brown f8a0d1c0b8 [efi] Check for protocols opened by vetoed driver and image handles
The UEFI specification states that the AgentHandle may be either the
driving binding protocol handle or the image handle.

Check for both handles when searching for stale handles to be forcibly
closed on behalf of a vetoed driver.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-06-23 16:51:10 +01:00
Michael Brown f0b1025503 [efi] Unload vetoed drivers by image handle rather than driver handle
In most cases, the driver handle will be the image handle itself.
However, this is not required by the UEFI specification, and some
images will install multiple driver binding handles.

Use the image handle (extracted from the driver binding protocol
instance) when attempting to unload the driver's image.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-06-23 16:51:10 +01:00
Michael Brown c832580f19 [efi] Pass more detailed driver information to veto methods
Pass the driver binding handle, the driver binding protocol instance,
the image handle, and the loaded image protocol instance to all veto
methods.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-06-23 16:22:27 +01:00
Michael Brown 9a118322a0 [efi] Show manufacturer in veto debug output
Simplify the process of adding new entries to the veto list by
including the manufacturer name within the standard debug output.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-06-22 23:20:37 +01:00
Michael Brown 25a3d3acab [efi] Veto the VMware UefiPxeBcDxe driver
The EDK2 UefiPxeBcDxe driver includes some remarkably convoluted and
unsafe logic in its driver binding protocol Start() and Stop() methods
in order to support a pair of nominally independent driver binding
protocols (one for IPv4, one for IPv6) sharing a single dynamically
allocated data structure.  This PXEBC_PRIVATE_DATA structure is
installed as a dummy protocol on the NIC handle in order to allow both
IPv4 and IPv6 driver binding protocols to locate it as needed.

The error handling code path in the UefiPxeBcDxe driver's Start()
method may attempt to uninstall the dummy protocol but fail to do so.
This failure is ignored and the containing memory is subsequently
freed anyway.  On the next invocation of the driver binding protocol,
it will find and use this already freed block of memory.  At some
point another memory allocation will occur, the PXEBC_PRIVATE_DATA
structure will be corrupted, and some undefined behaviour will occur.

The UEFI firmware used in VMware ESX 8 includes some proprietary
changes which attempt to install copies of the EFI_LOAD_FILE_PROTOCOL
and EFI_PXE_BASE_CODE_PROTOCOL instances from the IPv4 child handle
onto the NIC handle (along with a VMware-specific protocol with GUID
5190120d-453b-4d48-958d-f0bab3bc2161 and a NULL instance pointer).
This will inevitably fail with iPXE, since the NIC handle already
includes an EFI_LOAD_FILE_PROTOCOL instance.

These VMware proprietary changes end up triggering the unsafe error
handling code path described above.  The typical symptom is that an
attempt to exit from iPXE back to the UEFI firmware will crash the VM
with a General Protection fault from within the UefiPxeBcDxe driver:
this happens when the UefiPxeBcDxe driver's Stop() method attempts to
call through a function pointer in the (freed) PXEBC_PRIVATE_DATA
structure, but the function pointer has by then been overwritten by
UCS-2 character data from an unrelated memory allocation.

Work around this failure by adding the VMware UefiPxeBcDxe driver to
the driver veto list.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-06-08 12:24:07 +01:00
Michael Brown 3c040ad387 [efi] Veto the Itautec Ip4ConfigDxe driver
The Ip4ConfigDxe driver bug that was observed on Dell systems in
commit 64b4452 ("[efi] Blacklist the Dell Ip4ConfigDxe driver") has
also been observed on systems with a manufacturer name of "Itautec
S.A.".  The symptoms of the bug are identical: an attempt to call
DisconnectController() on the LOM device handle will lock up the
system.

Fix by extending the veto to cover the Ip4ConfigDxe driver for this
manufacturer.

Debugged-by: Celso Viana <celso.vianna@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-06-11 15:14:21 +01:00
Michael Brown e3eedb0be5 [efi] Avoid using potentially uninitialised driver name in veto checks
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-12-08 15:52:25 +00:00
Michael Brown b6e2ea03b0 [efi] Veto the HP XhciDxe Driver
The HP XhciDxe driver (observed on an HP EliteBook 840 G6) does not
respond correctly to driver disconnection, and will leave the PciIo
protocol instance opened with BY_DRIVER attributes even after
returning successfully from its Stop() method.  This prevents iPXE
from subsequently connecting to the PCI device handle.

Veto this driver if the iPXE build includes a native xHCI driver.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-11-30 19:34:57 +00:00
Michael Brown 63625b43e9 [efi] Allow vetoing of drivers that cannot be unloaded
Some UEFI drivers (observed with the "Usb Xhci Driver" on an HP
EliteBook) are particularly badly behaved: they cannot be unloaded and
will leave handles opened with BY_DRIVER attributes even after
disconnecting the driver, thereby preventing a replacement iPXE driver
from opening the handle.

Allow such drivers to be vetoed by falling back to a brute-force
mechanism that will disconnect the driver from all handles, uninstall
the driver binding protocol (to prevent it from attaching to any new
handles), and finally close any stray handles that the vetoed driver
has left open.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-11-30 19:34:57 +00:00
Michael Brown 354c252ee1 [efi] Provide manufacturer and driver names to all veto checking methods
Most veto checks are likely to use the manufacturer name and driver
name, so pass these as parameters to minimise code duplication.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-11-30 17:54:22 +00:00
Michael Brown 0b5467b658 [efi] Report correct error when failing to unload a vetoed driver
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-11-24 15:42:43 +00:00
Michael Brown 0e26220902 [efi] Rename efi_blacklist to efi_veto
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-11-07 23:30:56 +00:00