mm, kfence: bug on data corruption after error report

Trigger BUG when kfence encounters data corruption of kfence managed
objects. This allows a finer-grained control instead of globally
enabling panic_on_warn.

Signed-off-by: Levente Polyak <levente@leventepolyak.net>

lib/Kconfig.kfence

@@ -84,4 +84,13 @@ config KFENCE_KUNIT_TEST
 	  during boot; say M if you want the test to build as a module; say N
 	  if you are unsure.
 
+config KFENCE_BUG_ON_DATA_CORRUPTION
+	bool "Trigger a BUG when data corruption is detected"
+	default y
+	help
+	  Select this option if the kernel should BUG when kfence encounters
+	  data corruption of kfence managed objects after error report.
+
+	  If unsure, say Y.
+
 endif # KFENCE

mm/kfence/report.c

@@ -8,6 +8,7 @@
 #include <linux/stdarg.h>
 
 #include <linux/kernel.h>
+#include <linux/bug.h>
 #include <linux/lockdep.h>
 #include <linux/math.h>
 #include <linux/printk.h>
@@ -267,6 +268,10 @@ void kfence_report_error(unsigned long address, bool is_write, struct pt_regs *r
 
 	lockdep_on();
 
+#ifdef CONFIG_KFENCE_BUG_ON_DATA_CORRUPTION
+	BUG();
+#endif
+
 	check_panic_on_warn("KFENCE");
 
 	/* We encountered a memory safety error, taint the kernel! */