In a section header VirtualSize may be zero. This is for instance seen in the .sbat section of shim. In this case use SizeOfRawData as section size.
Fixes: 9d30a941cce5 ("efi_loader: don't load beyond VirtualSize") Signed-off-by: Heinrich Schuchardt heinrich.schuchardt@canonical.com --- lib/efi_loader/efi_image_loader.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-)
diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c index a0eb63fceb..838e3a7f02 100644 --- a/lib/efi_loader/efi_image_loader.c +++ b/lib/efi_loader/efi_image_loader.c @@ -800,6 +800,23 @@ efi_status_t efi_check_pe(void *buffer, size_t size, void **nt_header) return EFI_SUCCESS; }
+/** + * section_size() - determine size of section + * + * The size of a section in memory if normally given by VirtualSize. + * If VirtualSize is not provided, use SizeOfRawData. + * + * @sec: section header + * Return: size of section in memory + */ +static u32 section_size(IMAGE_SECTION_HEADER *sec) +{ + if (sec->Misc.VirtualSize) + return sec->Misc.VirtualSize; + else + return sec->SizeOfRawData; +} + /** * efi_load_pe() - relocate EFI binary * @@ -869,8 +886,9 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, /* Calculate upper virtual address boundary */ for (i = num_sections - 1; i >= 0; i--) { IMAGE_SECTION_HEADER *sec = §ions[i]; + virt_size = max_t(unsigned long, virt_size, - sec->VirtualAddress + sec->Misc.VirtualSize); + sec->VirtualAddress + section_size(sec)); }
/* Read 32/64bit specific header bits */ @@ -931,11 +949,16 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, /* Load sections into RAM */ for (i = num_sections - 1; i >= 0; i--) { IMAGE_SECTION_HEADER *sec = §ions[i]; - memset(efi_reloc + sec->VirtualAddress, 0, - sec->Misc.VirtualSize); + u32 copy_size = section_size(sec); + + if (copy_size > sec->SizeOfRawData) { + copy_size = sec->SizeOfRawData; + memset(efi_reloc + sec->VirtualAddress, 0, + sec->Misc.VirtualSize); + } memcpy(efi_reloc + sec->VirtualAddress, efi + sec->PointerToRawData, - min(sec->Misc.VirtualSize, sec->SizeOfRawData)); + copy_size); }
/* Run through relocations */