ladybird/Userland/Libraries/LibC/ssp.cpp
Keegan Saunders e575339564 LibELF: Add stack guard hardening
Employ the same hardening that glibc and the Linux kernel use for
generating stack guards: zero the first byte of the guard such that
if C-style string functions read out of bounds on the stack, we do
not overwrite or potentially leak the stack guard.
2022-11-29 11:04:21 +01:00

32 lines
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C++

/*
* Copyright (c) 2021, Brian Gianforcaro <bgianf@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Format.h>
#include <AK/Types.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/internals.h>
#include <unistd.h>
#if defined __SSP__ || defined __SSP_ALL__
# error "file must not be compiled with stack protection enabled on it. Use -fno-stack-protector"
#endif
extern "C" {
extern uintptr_t __stack_chk_guard;
// Initialized in `initialize_libc` (we leave a placeholder value here before initialization).
__attribute__((used)) uintptr_t __stack_chk_guard = (uintptr_t)0xc6c7c8c9;
__attribute__((noreturn)) void __stack_chk_fail()
{
dbgln("Error: USERSPACE({}) Stack protector failure, stack smashing detected!", getpid());
if (__stdio_is_initialized)
warnln("Error: Stack protector failure, stack smashing detected!");
abort();
}
} // extern "C"