elf_reader: check if ELF machine type is for BPF data

Signed-off-by: Florian Lehner <dev@der-flo.net>
cilium · Nov 2, 2022 · c92998d · c92998d
1 parent b4f36f0
commit c92998d
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Showing 3 changed files with 10 additions and 0 deletions.
diff --git a/elf_reader.go b/elf_reader.go
@@ -51,6 +51,12 @@ func LoadCollectionSpecFromReader(rd io.ReaderAt) (*CollectionSpec, error) {
 		return nil, err
 	}
 
+	// Checks if the ELF file is for BPF data.
+	// Old LLVM versions set e_machine to EM_NONE.
+	if f.File.Machine != unix.EM_NONE && f.File.Machine != elf.EM_BPF {
+		return nil, fmt.Errorf("unexpected machine type for BPF ELF: %s", f.File.Machine)
+	}
+
 	var (
 		licenseSection *elf.Section
 		versionSection *elf.Section

diff --git a/internal/unix/types_linux.go b/internal/unix/types_linux.go
@@ -75,6 +75,8 @@ const (
 	SIGPROF                   = linux.SIGPROF
 	SIG_BLOCK                 = linux.SIG_BLOCK
 	SIG_UNBLOCK               = linux.SIG_UNBLOCK
+	EM_NONE                   = linux.EM_NONE
+	EM_BPF                    = linux.EM_BPF
 )
 
 type Statfs_t = linux.Statfs_t

diff --git a/internal/unix/types_other.go b/internal/unix/types_other.go
@@ -79,6 +79,8 @@ const (
 	SIGPROF
 	SIG_BLOCK
 	SIG_UNBLOCK
+	EM_NONE
+	EM_BPF
 )
 
 type Statfs_t struct {