From: Jan Kiszka <[email protected]> Make sure we always roll back resource allocations and protocol registrations on errors so that nothing is leaked and nothing could break when running a different UEFI binary after the stub has failed. Requires to let replace_fdt return an error rather than terminating the stub.
Signed-off-by: Jan Kiszka <[email protected]> --- kernel-stub/fdt.c | 17 ++++++++++------ kernel-stub/kernel-stub.h | 3 ++- kernel-stub/main.c | 41 ++++++++++++++++++++++++++------------- 3 files changed, 40 insertions(+), 21 deletions(-) diff --git a/kernel-stub/fdt.c b/kernel-stub/fdt.c index 513aa76..b64cd7d 100644 --- a/kernel-stub/fdt.c +++ b/kernel-stub/fdt.c @@ -152,7 +152,7 @@ BOOLEAN match_fdt(const VOID *fdt, const CHAR8 *compatible) return strcmpa(compatible, alt_compatible) == 0; } -VOID replace_fdt(const VOID *fdt) +EFI_STATUS replace_fdt(const VOID *fdt) { const FDT_HEADER *header = fdt; EFI_DT_FIXUP_PROTOCOL *protocol; @@ -162,7 +162,8 @@ VOID replace_fdt(const VOID *fdt) status = LibLocateProtocol(&EfiDtFixupProtocol, (VOID **)&protocol); if (EFI_ERROR(status)) { - error_exit(L"Did not find device tree fixup protocol", status); + error(L"Did not find device tree fixup protocol", status); + return status; } /* Find out which size we need */ @@ -170,13 +171,15 @@ VOID replace_fdt(const VOID *fdt) status = protocol->Fixup(protocol, (VOID *)fdt, &size, EFI_DT_APPLY_FIXUPS); if (status != EFI_BUFFER_TOO_SMALL) { - error_exit(L"Device tree fixup: unexpected error", status); + error(L"Device tree fixup: unexpected error", status); + return status; } fdt_buffer = AllocatePool(size); if (!fdt_buffer) { - error_exit(L"Error allocating device tree buffer", - EFI_OUT_OF_RESOURCES); + status = EFI_OUT_OF_RESOURCES; + error(L"Error allocating device tree buffer", status); + return status; } CopyMem(fdt_buffer, fdt, BE32_TO_HOST(header->TotalSize)); @@ -185,6 +188,8 @@ VOID replace_fdt(const VOID *fdt) EFI_DT_INSTALL_TABLE); if (EFI_ERROR(status)) { FreePool(fdt_buffer); - error_exit(L"Device tree fixup failed", status); + error(L"Device tree fixup failed", status); } + + return status; } diff --git a/kernel-stub/kernel-stub.h b/kernel-stub/kernel-stub.h index 4944355..c0bd542 100644 --- a/kernel-stub/kernel-stub.h +++ b/kernel-stub/kernel-stub.h @@ -14,11 +14,12 @@ #include <efi.h> +VOID error(CHAR16 *message, EFI_STATUS status); VOID __attribute__((noreturn)) error_exit(CHAR16 *message, EFI_STATUS status); const VOID *get_fdt_compatible(VOID); BOOLEAN match_fdt(const VOID *fdt, const CHAR8 *compatible); -VOID replace_fdt(const VOID *fdt); +EFI_STATUS replace_fdt(const VOID *fdt); VOID install_initrd_loader(VOID *initrd, UINTN initrd_size); VOID uninstall_initrd_loader(VOID); diff --git a/kernel-stub/main.c b/kernel-stub/main.c index 95a9593..3858b24 100644 --- a/kernel-stub/main.c +++ b/kernel-stub/main.c @@ -53,17 +53,22 @@ typedef struct { static EFI_HANDLE this_image; static EFI_LOADED_IMAGE kernel_image; -VOID __attribute__((noreturn)) error_exit(CHAR16 *message, EFI_STATUS status) +static VOID info(CHAR16 *message) +{ + Print(L"Unified kernel stub: %s\n", message); +} + +VOID error(CHAR16 *message, EFI_STATUS status) { Print(L"Unified kernel stub: %s (%r).\n", message, status); (VOID) BS->Stall(3 * 1000 * 1000); - (VOID) BS->Exit(this_image, status, 0, NULL); - __builtin_unreachable(); } -static VOID info(CHAR16 *message) +VOID __attribute__((noreturn)) error_exit(CHAR16 *message, EFI_STATUS status) { - Print(L"Unified kernel stub: %s\n", message); + error(message, status); + (VOID) BS->Exit(this_image, status, 0, NULL); + __builtin_unreachable(); } static const PE_HEADER *get_pe_header(const VOID *image) @@ -93,7 +98,7 @@ EFI_STATUS efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *system_table) EFI_LOADED_IMAGE *stub_image; const PE_HEADER *pe_header; const SECTION *section; - EFI_STATUS status, kernel_status; + EFI_STATUS status, cleanup_status; UINTN n; this_image = image_handle; @@ -161,12 +166,15 @@ EFI_STATUS efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *system_table) &kernel_handle, &LoadedImageProtocol, &kernel_image, NULL); if (EFI_ERROR(status)) { - uninstall_initrd_loader(); - error_exit(L"Error registering kernel image", status); + error(L"Error registering kernel image", status); + goto cleanup_initrd; } if (alt_fdt) { - replace_fdt(alt_fdt); + status = replace_fdt(alt_fdt); + if (EFI_ERROR(status)) { + goto cleanup_protocols; + } info(L"Using matched embedded device tree"); } else if (fdt_compatible) { if (has_dtbs) { @@ -180,15 +188,20 @@ EFI_STATUS efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *system_table) ((UINT8 *) kernel_image.ImageBase + pe_header->Opt.AddressOfEntryPoint); - kernel_status = kernel_entry(kernel_handle, system_table); + status = kernel_entry(kernel_handle, system_table); - status = BS->UninstallMultipleProtocolInterfaces( +cleanup_protocols: + cleanup_status = BS->UninstallMultipleProtocolInterfaces( kernel_handle, &LoadedImageProtocol, &kernel_image, NULL); - if (EFI_ERROR(status)) { - error_exit(L"Error unregistering kernel image", status); + if (EFI_ERROR(cleanup_status)) { + error(L"Error unregistering kernel image", status); + if (!EFI_ERROR(status)) { + status = cleanup_status; + } } +cleanup_initrd: uninstall_initrd_loader(); - return kernel_status; + return status; } -- 2.35.3 -- You received this message because you are subscribed to the Google Groups "EFI Boot Guard" group. 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