libk: use a random value for the stack protector

Don't hardcode the __stack_chk_guard value, generate a random value
(using RDRAND on x86) before running any C code.

Signed-off-by: Danny Holman <dholman@gymli.org>

1 files changed, 3 insertions, 5 deletions

diff --git a/libk/stack_protector.c b/libk/stack_protector.c
index 78d0302..a929ae0 100644
--- a/libk/stack_protector.c
+++ b/libk/stack_protector.c
@@ -1,11 +1,9 @@
 #include <kernel/panic.h>
 #include <stdint.h>
-#include <stddef.h>
 
-#define STACK_CHK_GUARD 0x32E3429E
-
-uintptr_t __stack_chk_guard = STACK_CHK_GUARD;
+uintptr_t __stack_chk_guard;
 
 __attribute__((noreturn)) void __stack_chk_fail(void) {
-        panic("STACK SMASHING IN KERNEL ADDRESS SPACE");
+        panic("Detected attempted stack manipulation in kernel");
+        while(1);
 }