In the bootparams struct, init_size defines the static footprint of the bzImage, counted from the start of the kernel image, i.e., startup_32(). The PE/COFF metadata declares the same size for the entire image, but this time, the image includes the setup block as well, and so the space reserved by UEFI is a bit too small. This usually doesn't matter, since we normally relocate the kernel into a memory allocation of the correct size. But in the unlikely case that the image happens to be loaded at exactly the preferred offset, we skip this relocation, and execute the image in place, stepping on memory beyond the provided allocation, which may be in use for other purposes. Let's fix this by adding the size of the setup block to the image size as declared in the PE/COFF header. Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> --- arch/x86/boot/tools/build.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c index 55e669d29e54..c08db2ee4ba2 100644 --- a/arch/x86/boot/tools/build.c +++ b/arch/x86/boot/tools/build.c @@ -408,7 +408,7 @@ int main(int argc, char ** argv) update_pecoff_text(setup_sectors * 512, i + (sys_size * 16)); init_sz = get_unaligned_le32(&buf[0x260]); - update_pecoff_bss(i + (sys_size * 16), init_sz); + update_pecoff_bss(i + (sys_size * 16), init_sz + setup_sectors * 512); efi_stub_entry_update(); -- 2.17.1
