kernel.git/drivers/firmware/efi/libstub, branch linux-5.6.y

efi/libstub: Avoid returning uninitialized data from setup_graphics()

2020-06-07T11:16:45Z

[ Upstream commit 081d5150845ba3fa49151a2f55d3cc03b0987509 ] Currently, setup_graphics() ignores the return value of efi_setup_gop(). As AllocatePool() does not zero out memory, the screen information table will contain uninitialized data in this case. We should free the screen information table if efi_setup_gop() returns an error code. Signed-off-by: Heinrich Schuchardt Link: https://lore.kernel.org/r/20200426194946.112768-1-xypron.glpk@gmx.de Signed-off-by: Ard Biesheuvel Signed-off-by: Sasha Levin

tpm: check event log version before reading final events

2020-05-27T15:48:28Z

commit b4f1874c62168159fdb419ced4afc77c1b51c475 upstream. This fixes the boot issues since 5.3 on several Dell models when the TPM is enabled. Depending on the exact grub binary, booting the kernel would freeze early, or just report an error parsing the final events log. We get an event log in the SHA-1 format, which doesn't have a tcg_efi_specid_event_head in the first event, and there is a final events table which doesn't match the crypto agile format. __calc_tpm2_event_size reads bad "count" and "efispecid->num_algs", and either fails, or loops long enough for the machine to be appear frozen. So we now only parse the final events table, which is per the spec always supposed to be in the crypto agile format, when we got a event log in this format. Fixes: c46f3405692de ("tpm: Reserve the TPM final events table") Fixes: 166a2809d65b2 ("tpm: Don't duplicate events from the final event log in the TCG2 log") Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1779611 Signed-off-by: Loïc Yhuel Link: https://lore.kernel.org/r/20200512040113.277768-1-loic.yhuel@gmail.com Reviewed-by: Javier Martinez Canillas Reviewed-by: Jerry Snitselaar Reviewed-by: Matthew Garrett [ardb: warn when final events table is missing or in the wrong format] Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

efi: Allow disabling PCI busmastering on bridges during boot

2020-01-10T17:55:04Z

Add an option to disable the busmaster bit in the control register on all PCI bridges before calling ExitBootServices() and passing control to the runtime kernel. System firmware may configure the IOMMU to prevent malicious PCI devices from being able to attack the OS via DMA. However, since firmware can't guarantee that the OS is IOMMU-aware, it will tear down IOMMU configuration when ExitBootServices() is called. This leaves a window between where a hostile device could still cause damage before Linux configures the IOMMU again. If CONFIG_EFI_DISABLE_PCI_DMA is enabled or "efi=disable_early_pci_dma" is passed on the command line, the EFI stub will clear the busmaster bit on all PCI bridges before ExitBootServices() is called. This will prevent any malicious PCI devices from being able to perform DMA until the kernel reenables busmastering after configuring the IOMMU. This option may cause failures with some poorly behaved hardware and should not be enabled without testing. The kernel commandline options "efi=disable_early_pci_dma" or "efi=no_disable_early_pci_dma" may be used to override the default. Note that PCI devices downstream from PCI bridges are disconnected from their drivers first, using the UEFI driver model API, so that DMA can be disabled safely at the bridge level. [ardb: disconnect PCI I/O handles first, as suggested by Arvind] Co-developed-by: Matthew Garrett Signed-off-by: Matthew Garrett Signed-off-by: Ard Biesheuvel Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Arvind Sankar Cc: Matthew Garrett Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-18-ardb@kernel.org Signed-off-by: Ingo Molnar

efi/x86: Allow translating 64-bit arguments for mixed mode calls

2020-01-10T17:55:04Z

Introduce the ability to define macros to perform argument translation for the calls that need it, and define them for the boot services that we currently use. When calling 32-bit firmware methods in mixed mode, all output parameters that are 32-bit according to the firmware, but 64-bit in the kernel (ie OUT UINTN * or OUT VOID **) must be initialized in the kernel, or the upper 32 bits may contain garbage. Define macros that zero out the upper 32 bits of the output before invoking the firmware method. When a 32-bit EFI call takes 64-bit arguments, the mixed-mode call must push the two 32-bit halves as separate arguments onto the stack. This can be achieved by splitting the argument into its two halves when calling the assembler thunk. Define a macro to do this for the free_pages boot service. Signed-off-by: Arvind Sankar Signed-off-by: Ard Biesheuvel Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Matthew Garrett Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-17-ardb@kernel.org Signed-off-by: Ingo Molnar

efi/libstub: Tidy up types and names of global cmdline variables

2019-12-25T09:49:25Z

Drop leading underscores and use bool not int for true/false variables set on the command line. Signed-off-by: Ard Biesheuvel Cc: Arvind Sankar Cc: Borislav Petkov Cc: James Morse Cc: Matt Fleming Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-25-ardb@kernel.org Signed-off-by: Ingo Molnar

efi/libstub: Rename efi_call_early/_runtime macros to be more intuitive

2019-12-25T09:49:25Z

The macros efi_call_early and efi_call_runtime are used to call EFI boot services and runtime services, respectively. However, the naming is confusing, given that the early vs runtime distinction may suggest that these are used for calling the same set of services either early or late (== at runtime), while in reality, the sets of services they can be used with are completely disjoint, and efi_call_runtime is also only usable in 'early' code. So do a global sweep to replace all occurrences with efi_bs_call or efi_rt_call, respectively, where BS and RT match the idiom used by the UEFI spec to refer to boot time or runtime services. While at it, use 'func' as the macro parameter name for the function pointers, which is less likely to collide and cause weird build errors. Signed-off-by: Ard Biesheuvel Cc: Arvind Sankar Cc: Borislav Petkov Cc: James Morse Cc: Matt Fleming Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-24-ardb@kernel.org Signed-off-by: Ingo Molnar

efi/libstub: Drop 'table' argument from efi_table_attr() macro

2019-12-25T09:49:24Z

None of the definitions of the efi_table_attr() still refer to their 'table' argument so let's get rid of it entirely. Signed-off-by: Ard Biesheuvel Cc: Arvind Sankar Cc: Borislav Petkov Cc: James Morse Cc: Matt Fleming Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-23-ardb@kernel.org Signed-off-by: Ingo Molnar

efi/libstub: Drop protocol argument from efi_call_proto() macro

2019-12-25T09:49:24Z

After refactoring the mixed mode support code, efi_call_proto() no longer uses its protocol argument in any of its implementation, so let's remove it altogether. Signed-off-by: Ard Biesheuvel Cc: Arvind Sankar Cc: Borislav Petkov Cc: James Morse Cc: Matt Fleming Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-22-ardb@kernel.org Signed-off-by: Ingo Molnar

efi/libstub/x86: Work around page freeing issue in mixed mode

2019-12-25T09:49:23Z

Mixed mode translates calls from the 64-bit kernel into the 32-bit firmware by wrapping them in a call to a thunking routine that pushes a 32-bit word onto the stack for each argument passed to the function, regardless of the argument type. This works surprisingly well for most services and protocols, with the exception of ones that take explicit 64-bit arguments. efi_free() invokes the FreePages() EFI boot service, which takes a efi_physical_addr_t as its address argument, and this is one of those 64-bit types. This means that the 32-bit firmware will interpret the (addr, size) pair as a single 64-bit quantity, and since it is guaranteed to have the high word set (as size > 0), it will always fail due to the fact that EFI memory allocations are always < 4 GB on 32-bit firmware. So let's fix this by giving the thunking code a little hand, and pass two values for the address, and a third one for the size. Signed-off-by: Ard Biesheuvel Cc: Arvind Sankar Cc: Borislav Petkov Cc: James Morse Cc: Matt Fleming Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-21-ardb@kernel.org Signed-off-by: Ingo Molnar

efi/libstub: Remove 'sys_table_arg' from all function prototypes

2019-12-25T09:49:23Z

We have a helper efi_system_table() that gives us the address of the EFI system table in memory, so there is no longer point in passing it around from each function to the next. Signed-off-by: Ard Biesheuvel Cc: Arvind Sankar Cc: Borislav Petkov Cc: James Morse Cc: Matt Fleming Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-20-ardb@kernel.org Signed-off-by: Ingo Molnar