Kernel: Expose sysctl 'ubsan_is_deadly' to panic the Kernel on UB

This makes it easier to find UB, for example when fuzzing the Kernel.

This can be enabled by default, thanks to @boricj's work in
32e1354b9b0050dd2920c8506cef2841789e14df.

1 files changed, 7 insertions, 0 deletions

diff --git a/Kernel/FileSystem/ProcFS.cpp b/Kernel/FileSystem/ProcFS.cpp
index df7deae852..7829b38e2f 100644
--- a/Kernel/FileSystem/ProcFS.cpp
+++ b/Kernel/FileSystem/ProcFS.cpp
@@ -59,6 +59,7 @@
 #include <Kernel/Scheduler.h>
 #include <Kernel/StdLib.h>
 #include <Kernel/TTY/TTY.h>
+#include <Kernel/UBSanitizer.h>
 #include <Kernel/VM/AnonymousVMObject.h>
 #include <Kernel/VM/MemoryManager.h>
 #include <LibC/errno_numbers.h>
@@ -994,6 +995,7 @@ void ProcFS::add_sys_string(String&& name, Lockable<String>& var, Function<void(
 bool ProcFS::initialize()
 {
     static Lockable<bool>* kmalloc_stack_helper;
+    static Lockable<bool>* ubsan_deadly_helper;
 
     if (kmalloc_stack_helper == nullptr) {
         kmalloc_stack_helper = new Lockable<bool>();
@@ -1001,6 +1003,11 @@ bool ProcFS::initialize()
         ProcFS::add_sys_bool("kmalloc_stacks", *kmalloc_stack_helper, [] {
             g_dump_kmalloc_stacks = kmalloc_stack_helper->resource();
         });
+        ubsan_deadly_helper = new Lockable<bool>();
+        ubsan_deadly_helper->resource() = UBSanitizer::g_ubsan_is_deadly;
+        ProcFS::add_sys_bool("ubsan_is_deadly", *ubsan_deadly_helper, [] {
+            UBSanitizer::g_ubsan_is_deadly = ubsan_deadly_helper->resource();
+        });
     }
     return true;
 }