libsel4utils: check variable before dereferencing

libsel4utils/src/elf.c

diff --git a/libsel4utils/src/elf.c b/libsel4utils/src/elf.c
index 18db1f3..6767d16 100644
--- a/libsel4utils/src/elf.c
+++ b/libsel4utils/src/elf.c
@@ -514,8 +514,11 @@
 uintptr_t sel4utils_elf_get_vsyscall(elf_t *elf_file)
 {
     uintptr_t* addr = (uintptr_t*)sel4utils_elf_get_section(elf_file, "__vsyscall", NULL);
-    /* Hope everything is good and just dereference it */
-    return *addr;
+    if (addr) {
+        return *addr;
+    } else {
+        return 0;
+    }
 }
 
 uintptr_t sel4utils_elf_get_section(elf_t *elf_file, const char *section_name, uint64_t* section_size)