chore: added arch expected machine in kernel boot path

Author: Sawangg

src/pe/fixtures.rs

@@ -2,6 +2,8 @@
 
 use object::pe::IMAGE_DIRECTORY_ENTRY_BASERELOC;
 
+use super::kernel::EXPECTED_MACHINE;
+
 pub(crate) const FILE_ALIGN_U32: u32 = 0x200;
 
 const FILE_ALIGN: usize = 0x200;
@@ -26,7 +28,7 @@ impl Builder {
         Self::write_bytes(&mut data, NT_OFFSET, b"PE");
 
         let file_header = Self::offset(NT_OFFSET, 4);
-        Self::write_u16(&mut data, file_header, 0x8664);
+        Self::write_u16(&mut data, file_header, EXPECTED_MACHINE);
         Self::write_u16(&mut data, Self::offset(file_header, 16), 0xF0);
         Self::write_u16(&mut data, Self::offset(file_header, 18), 0x0002);
 
@@ -105,6 +107,10 @@ impl Builder {
         );
     }
 
+    pub(crate) fn set_machine(&mut self, value: u16) {
+        Self::write_u16(&mut self.data, Self::offset(NT_OFFSET, 4), value);
+    }
+
     pub(crate) fn set_last_ptr_relocs(&mut self, ptr: u32) {
         let section_header = self.last_section_header_offset();
         Self::write_u32(&mut self.data, Self::offset(section_header, 24), ptr);

src/pe/kernel.rs

@@ -9,6 +9,16 @@ use object::pe::{
 };
 use object::read::pe::{ImageNtHeaders as _, SectionTable};
 
+/// `IMAGE_FILE_MACHINE` value required for kernels loaded by this target.
+#[cfg(target_arch = "x86_64")]
+pub(crate) const EXPECTED_MACHINE: u16 = object::pe::IMAGE_FILE_MACHINE_AMD64;
+/// `IMAGE_FILE_MACHINE` value required for kernels loaded by this target.
+#[cfg(target_arch = "aarch64")]
+pub(crate) const EXPECTED_MACHINE: u16 = object::pe::IMAGE_FILE_MACHINE_ARM64;
+/// `IMAGE_FILE_MACHINE` value required for kernels loaded by this target.
+#[cfg(target_arch = "riscv64")]
+pub(crate) const EXPECTED_MACHINE: u16 = object::pe::IMAGE_FILE_MACHINE_RISCV64;
+
 /// `IMAGE_DLLCHARACTERISTICS_NX_COMPAT`.
 const NX_COMPAT: u16 = 0x0100;
 
@@ -42,6 +52,13 @@ impl<'a> Image<'a> {
             .sections(data, offset)
             .context("invalid section table")?;
 
+        let machine = nt_headers.file_header.machine.get(LE);
+        ensure!(
+            machine == EXPECTED_MACHINE,
+            "kernel PE machine 0x{machine:04x} is not supported on this target \
+             (expected 0x{EXPECTED_MACHINE:04x})"
+        );
+
         let optional_header = &nt_headers.optional_header;
         let entry_point_rva = optional_header.address_of_entry_point.get(LE);
         let base_address = optional_header.image_base.get(LE);
@@ -127,6 +144,21 @@ mod tests {
         assert!(err.to_string().contains("invalid PE headers"), "{err}");
     }
 
+    #[test]
+    fn parse_wrong_machine_rejected() {
+        // ARRANGE
+        let mut builder = Builder::new();
+        builder.add_section(*b".text\0\0\0", &[0_u8; 16]);
+        builder.set_machine(0);
+        let data = builder.build();
+
+        // ACT
+        let err = Image::parse(&data).unwrap_err();
+
+        // ASSERT
+        assert!(err.to_string().contains("machine"), "{err}");
+    }
+
     #[test]
     fn parse_no_entry_point() {
         // ARRANGE