From 1bc9fc3483ece303ad7181ea024312248d8ce928 Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Tue, 2 Feb 2021 07:27:42 +0100 Subject: [PATCH] efi_loader: only check size if EFI_DT_APPLY_FIXUPS In the implementation of the EFI_DT_FIXUP_PROTOCOL: * Only check the buffer size when EFI_DT_APPLY_FIXUPS is set. * In this case the field totalsize of the device-tree may not exceed the buffer size. * Install device-tree only if EFI_DT_INSTALL_TABLE is set. Signed-off-by: Heinrich Schuchardt --- lib/efi_loader/efi_dt_fixup.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/lib/efi_loader/efi_dt_fixup.c b/lib/efi_loader/efi_dt_fixup.c index 3850ab3b0f..6de57b84d2 100644 --- a/lib/efi_loader/efi_dt_fixup.c +++ b/lib/efi_loader/efi_dt_fixup.c @@ -110,6 +110,7 @@ efi_dt_fixup(struct efi_dt_fixup_protocol *this, void *dtb, { efi_status_t ret; size_t required_size; + size_t total_size; bootm_headers_t img = { 0 }; EFI_ENTRY("%p, %p, %p, %d", this, dtb, buffer_size, flags); @@ -124,20 +125,20 @@ efi_dt_fixup(struct efi_dt_fixup_protocol *this, void *dtb, goto out; } if (flags & EFI_DT_APPLY_FIXUPS) { + /* Check size */ required_size = fdt_off_dt_strings(dtb) + fdt_size_dt_strings(dtb) + 0x3000; - } else { - required_size = fdt_totalsize(dtb); - } - if (required_size > *buffer_size) { - *buffer_size = required_size; - ret = EFI_BUFFER_TOO_SMALL; - goto out; - } - fdt_set_totalsize(dtb, *buffer_size); + total_size = fdt_totalsize(dtb); + if (required_size < total_size) + required_size = total_size; + if (required_size > *buffer_size) { + *buffer_size = required_size; + ret = EFI_BUFFER_TOO_SMALL; + goto out; + } - if (flags & EFI_DT_APPLY_FIXUPS) { + fdt_set_totalsize(dtb, *buffer_size); if (image_setup_libfdt(&img, dtb, 0, NULL)) { log_err("failed to process device tree\n"); ret = EFI_INVALID_PARAMETER; @@ -147,10 +148,10 @@ efi_dt_fixup(struct efi_dt_fixup_protocol *this, void *dtb, if (flags & EFI_DT_RESERVE_MEMORY) efi_carve_out_dt_rsv(dtb); - if (EFI_DT_INSTALL_TABLE) { + if (flags & EFI_DT_INSTALL_TABLE) { ret = efi_install_configuration_table(&efi_guid_fdt, dtb); if (ret != EFI_SUCCESS) { - log_err("ERROR: failed to install device tree\n"); + log_err("failed to install device tree\n"); goto out; } } -- 2.39.5