ExitBootServices() repoints systab->runtime at a separate table with the detached runtime services. If an EFI application caches RT, it may end up calling into the stale boot-time runtime services object.
Fix this by keeping the systab->runtime pointer the same and do a "deep copy" by rewriting the object including its callbacks instead. Cc: Johannes Schauer Marin Rodrigues <[email protected]> Fixes: 699145f1cb22 ("efi: runtime: add runtime service support after ExitBootServices") Signed-off-by: Ahmad Fatoum <[email protected]> --- efi/loader/boot.c | 5 ++++- efi/loader/runtime.c | 2 +- efi/loader/watchdog.c | 4 ++-- efi/runtime/services.c | 3 ++- include/efi/loader.h | 2 +- 5 files changed, 10 insertions(+), 6 deletions(-) diff --git a/efi/loader/boot.c b/efi/loader/boot.c index 2d98c95b5c34..ddfbf33bff69 100644 --- a/efi/loader/boot.c +++ b/efi/loader/boot.c @@ -3879,6 +3879,8 @@ static struct efi_boot_services efi_boot_services = { static __efi_runtime_data u16 firmware_vendor[] = L"barebox"; +static __efi_runtime_data struct efi_runtime_services efi_runtime_services; + __efi_runtime_data struct efi_system_table systab = { .hdr = { .signature = EFI_SYSTEM_TABLE_SIGNATURE, @@ -3925,8 +3927,9 @@ efi_status_t efi_initialize_system_table(void) systab.boottime = &efi_boot_services; /* - * This will be overwritten dynamically at detach time. + * This must be overwritten dynamically at detach time. */ + efi_runtime_services = efi_runtime_services_boot; systab.runtime = &efi_runtime_services; /* Set CRC32 field in table headers */ diff --git a/efi/loader/runtime.c b/efi/loader/runtime.c index a8f872f23b48..329e1077889f 100644 --- a/efi/loader/runtime.c +++ b/efi/loader/runtime.c @@ -293,7 +293,7 @@ static efi_status_t EFIAPI efi_set_time_boottime(struct efi_time *time) * the runtime services will be replaced by the detached implementation, * so we need not take any special consideration here. */ -struct efi_runtime_services efi_runtime_services = { +struct efi_runtime_services efi_runtime_services_boot = { .hdr = { .signature = EFI_RUNTIME_SERVICES_SIGNATURE, .revision = EFI_SPECIFICATION_VERSION, diff --git a/efi/loader/watchdog.c b/efi/loader/watchdog.c index a4715c149add..c29f91a0aa07 100644 --- a/efi/loader/watchdog.c +++ b/efi/loader/watchdog.c @@ -35,8 +35,8 @@ static void EFIAPI efi_watchdog_timer_notify(struct efi_event *event, EFI_ENTRY("%p, %p", event, context); pr_emerg("\nEFI: Watchdog timeout\n"); - EFI_CALL_VOID(efi_runtime_services.reset_system(EFI_RESET_COLD, - EFI_SUCCESS, 0, NULL)); + EFI_CALL_VOID(systab.runtime->reset_system(EFI_RESET_COLD, + EFI_SUCCESS, 0, NULL)); EFI_EXIT(EFI_UNSUPPORTED); } diff --git a/efi/runtime/services.c b/efi/runtime/services.c index 5044e16c7c5c..dc4960ac4763 100644 --- a/efi/runtime/services.c +++ b/efi/runtime/services.c @@ -293,7 +293,8 @@ void efi_runtime_detach(struct efi_system_table *systab) systab->std_err = NULL; systab->boottime = NULL; - systab->runtime = &efi_runtime_services_detached; + /* Payloads may have cached systab->runtime, so patch it in place */ + *systab->runtime = efi_runtime_services_detached; /* Recalculate CRC32 */ efi_update_table_header_crc32(&systab->hdr); diff --git a/include/efi/loader.h b/include/efi/loader.h index 4dcd15854560..0ccc0a720a90 100644 --- a/include/efi/loader.h +++ b/include/efi/loader.h @@ -19,7 +19,7 @@ struct efi_table_hdr; /* Key identifying current memory map */ extern efi_uintn_t efi_memory_map_key; -extern struct efi_runtime_services efi_runtime_services; +extern struct efi_runtime_services efi_runtime_services_boot; extern struct efi_system_table systab; extern struct efi_simple_text_output_protocol efi_con_out; -- 2.47.3
