mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-31 16:38:12 +00:00
UBSAN: run-time undefined behavior sanity checker
UBSAN uses compile-time instrumentation to catch undefined behavior (UB). Compiler inserts code that perform certain kinds of checks before operations that could cause UB. If check fails (i.e. UB detected) __ubsan_handle_* function called to print error message. So the most of the work is done by compiler. This patch just implements ubsan handlers printing errors. GCC has this capability since 4.9.x [1] (see -fsanitize=undefined option and its suboptions). However GCC 5.x has more checkers implemented [2]. Article [3] has a bit more details about UBSAN in the GCC. [1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html [2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html [3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/ Issues which UBSAN has found thus far are: Found bugs: * out-of-bounds access -97840cb67f
("netfilter: nfnetlink: fix insufficient validation in nfnetlink_bind") undefined shifts: *d48458d4a7
("jbd2: use a better hash function for the revoke table") *10632008b9
("clockevents: Prevent shift out of bounds") * 'x << -1' shift in ext4 - http://lkml.kernel.org/r/<5444EF21.8020501@samsung.com> * undefined rol32(0) - http://lkml.kernel.org/r/<1449198241-20654-1-git-send-email-sasha.levin@oracle.com> * undefined dirty_ratelimit calculation - http://lkml.kernel.org/r/<566594E2.3050306@odin.com> * undefined roundown_pow_of_two(0) - http://lkml.kernel.org/r/<1449156616-11474-1-git-send-email-sasha.levin@oracle.com> * [WONTFIX] undefined shift in __bpf_prog_run - http://lkml.kernel.org/r/<CACT4Y+ZxoR3UjLgcNdUm4fECLMx2VdtfrENMtRRCdgHB2n0bJA@mail.gmail.com> WONTFIX here because it should be fixed in bpf program, not in kernel. signed overflows: *32a8df4e0b
("sched: Fix odd values in effective_load() calculations") * mul overflow in ntp - http://lkml.kernel.org/r/<1449175608-1146-1-git-send-email-sasha.levin@oracle.com> * incorrect conversion into rtc_time in rtc_time64_to_tm() - http://lkml.kernel.org/r/<1449187944-11730-1-git-send-email-sasha.levin@oracle.com> * unvalidated timespec in io_getevents() - http://lkml.kernel.org/r/<CACT4Y+bBxVYLQ6LtOKrKtnLthqLHcw-BMp3aqP3mjdAvr9FULQ@mail.gmail.com> * [NOTABUG] signed overflow in ktime_add_safe() - http://lkml.kernel.org/r/<CACT4Y+aJ4muRnWxsUe1CMnA6P8nooO33kwG-c8YZg=0Xc8rJqw@mail.gmail.com> [akpm@linux-foundation.org: fix unused local warning] [akpm@linux-foundation.org: fix __int128 build woes] Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Marek <mmarek@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yury Gribov <y.gribov@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
68920c9732
commit
c6d308534a
17 changed files with 693 additions and 1 deletions
84
Documentation/ubsan.txt
Normal file
84
Documentation/ubsan.txt
Normal file
|
@ -0,0 +1,84 @@
|
|||
Undefined Behavior Sanitizer - UBSAN
|
||||
|
||||
Overview
|
||||
--------
|
||||
|
||||
UBSAN is a runtime undefined behaviour checker.
|
||||
|
||||
UBSAN uses compile-time instrumentation to catch undefined behavior (UB).
|
||||
Compiler inserts code that perform certain kinds of checks before operations
|
||||
that may cause UB. If check fails (i.e. UB detected) __ubsan_handle_*
|
||||
function called to print error message.
|
||||
|
||||
GCC has that feature since 4.9.x [1] (see -fsanitize=undefined option and
|
||||
its suboptions). GCC 5.x has more checkers implemented [2].
|
||||
|
||||
Report example
|
||||
---------------
|
||||
|
||||
================================================================================
|
||||
UBSAN: Undefined behaviour in ../include/linux/bitops.h:110:33
|
||||
shift exponent 32 is to large for 32-bit type 'unsigned int'
|
||||
CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.0-rc1+ #26
|
||||
0000000000000000 ffffffff82403cc8 ffffffff815e6cd6 0000000000000001
|
||||
ffffffff82403cf8 ffffffff82403ce0 ffffffff8163a5ed 0000000000000020
|
||||
ffffffff82403d78 ffffffff8163ac2b ffffffff815f0001 0000000000000002
|
||||
Call Trace:
|
||||
[<ffffffff815e6cd6>] dump_stack+0x45/0x5f
|
||||
[<ffffffff8163a5ed>] ubsan_epilogue+0xd/0x40
|
||||
[<ffffffff8163ac2b>] __ubsan_handle_shift_out_of_bounds+0xeb/0x130
|
||||
[<ffffffff815f0001>] ? radix_tree_gang_lookup_slot+0x51/0x150
|
||||
[<ffffffff8173c586>] _mix_pool_bytes+0x1e6/0x480
|
||||
[<ffffffff83105653>] ? dmi_walk_early+0x48/0x5c
|
||||
[<ffffffff8173c881>] add_device_randomness+0x61/0x130
|
||||
[<ffffffff83105b35>] ? dmi_save_one_device+0xaa/0xaa
|
||||
[<ffffffff83105653>] dmi_walk_early+0x48/0x5c
|
||||
[<ffffffff831066ae>] dmi_scan_machine+0x278/0x4b4
|
||||
[<ffffffff8111d58a>] ? vprintk_default+0x1a/0x20
|
||||
[<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
|
||||
[<ffffffff830b2240>] setup_arch+0x405/0xc2c
|
||||
[<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
|
||||
[<ffffffff830ae053>] start_kernel+0x83/0x49a
|
||||
[<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
|
||||
[<ffffffff830ad386>] x86_64_start_reservations+0x2a/0x2c
|
||||
[<ffffffff830ad4f3>] x86_64_start_kernel+0x16b/0x17a
|
||||
================================================================================
|
||||
|
||||
Usage
|
||||
-----
|
||||
|
||||
To enable UBSAN configure kernel with:
|
||||
|
||||
CONFIG_UBSAN=y
|
||||
|
||||
and to check the entire kernel:
|
||||
|
||||
CONFIG_UBSAN_SANITIZE_ALL=y
|
||||
|
||||
To enable instrumentation for specific files or directories, add a line
|
||||
similar to the following to the respective kernel Makefile:
|
||||
|
||||
For a single file (e.g. main.o):
|
||||
UBSAN_SANITIZE_main.o := y
|
||||
|
||||
For all files in one directory:
|
||||
UBSAN_SANITIZE := y
|
||||
|
||||
To exclude files from being instrumented even if
|
||||
CONFIG_UBSAN_SANITIZE_ALL=y, use:
|
||||
|
||||
UBSAN_SANITIZE_main.o := n
|
||||
and:
|
||||
UBSAN_SANITIZE := n
|
||||
|
||||
Detection of unaligned accesses controlled through the separate option -
|
||||
CONFIG_UBSAN_ALIGNMENT. It's off by default on architectures that support
|
||||
unaligned accesses (CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y). One could
|
||||
still enable it in config, just note that it will produce a lot of UBSAN
|
||||
reports.
|
||||
|
||||
References
|
||||
----------
|
||||
|
||||
[1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
|
||||
[2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
|
3
Makefile
3
Makefile
|
@ -411,7 +411,7 @@ export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE
|
|||
export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
|
||||
|
||||
export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
|
||||
export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KASAN
|
||||
export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KASAN CFLAGS_UBSAN
|
||||
export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
|
||||
export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
|
||||
export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
|
||||
|
@ -784,6 +784,7 @@ endif
|
|||
|
||||
include scripts/Makefile.kasan
|
||||
include scripts/Makefile.extrawarn
|
||||
include scripts/Makefile.ubsan
|
||||
|
||||
# Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
|
||||
# last assignments
|
||||
|
|
|
@ -31,6 +31,7 @@ config X86
|
|||
select ARCH_HAS_PMEM_API if X86_64
|
||||
select ARCH_HAS_MMIO_FLUSH
|
||||
select ARCH_HAS_SG_CHAIN
|
||||
select ARCH_HAS_UBSAN_SANITIZE_ALL
|
||||
select ARCH_HAVE_NMI_SAFE_CMPXCHG
|
||||
select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
|
||||
select ARCH_MIGHT_HAVE_PC_PARPORT
|
||||
|
|
|
@ -60,6 +60,7 @@ clean-files += cpustr.h
|
|||
KBUILD_CFLAGS := $(USERINCLUDE) $(REALMODE_CFLAGS) -D_SETUP
|
||||
KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__
|
||||
GCOV_PROFILE := n
|
||||
UBSAN_SANITIZE := n
|
||||
|
||||
$(obj)/bzImage: asflags-y := $(SVGA_MODE)
|
||||
|
||||
|
|
|
@ -33,6 +33,7 @@ KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector)
|
|||
|
||||
KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__
|
||||
GCOV_PROFILE := n
|
||||
UBSAN_SANITIZE :=n
|
||||
|
||||
LDFLAGS := -m elf_$(UTS_MACHINE)
|
||||
LDFLAGS_vmlinux := -T
|
||||
|
|
|
@ -4,6 +4,7 @@
|
|||
|
||||
KBUILD_CFLAGS += $(DISABLE_LTO)
|
||||
KASAN_SANITIZE := n
|
||||
UBSAN_SANITIZE := n
|
||||
|
||||
VDSO64-$(CONFIG_X86_64) := y
|
||||
VDSOX32-$(CONFIG_X86_X32_ABI) := y
|
||||
|
|
|
@ -70,3 +70,4 @@ KBUILD_CFLAGS := $(LINUXINCLUDE) $(REALMODE_CFLAGS) -D_SETUP -D_WAKEUP \
|
|||
-I$(srctree)/arch/x86/boot
|
||||
KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__
|
||||
GCOV_PROFILE := n
|
||||
UBSAN_SANITIZE := n
|
||||
|
|
|
@ -22,6 +22,7 @@ KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \
|
|||
|
||||
GCOV_PROFILE := n
|
||||
KASAN_SANITIZE := n
|
||||
UBSAN_SANITIZE := n
|
||||
|
||||
lib-y := efi-stub-helper.o
|
||||
|
||||
|
|
|
@ -1643,6 +1643,9 @@ struct task_struct {
|
|||
struct held_lock held_locks[MAX_LOCK_DEPTH];
|
||||
gfp_t lockdep_reclaim_gfp;
|
||||
#endif
|
||||
#ifdef CONFIG_UBSAN
|
||||
unsigned int in_ubsan;
|
||||
#endif
|
||||
|
||||
/* journalling filesystem info */
|
||||
void *journal_info;
|
||||
|
|
|
@ -1893,6 +1893,8 @@ source "samples/Kconfig"
|
|||
|
||||
source "lib/Kconfig.kgdb"
|
||||
|
||||
source "lib/Kconfig.ubsan"
|
||||
|
||||
config ARCH_HAS_DEVMEM_IS_ALLOWED
|
||||
bool
|
||||
|
||||
|
|
29
lib/Kconfig.ubsan
Normal file
29
lib/Kconfig.ubsan
Normal file
|
@ -0,0 +1,29 @@
|
|||
config ARCH_HAS_UBSAN_SANITIZE_ALL
|
||||
bool
|
||||
|
||||
config UBSAN
|
||||
bool "Undefined behaviour sanity checker"
|
||||
help
|
||||
This option enables undefined behaviour sanity checker
|
||||
Compile-time instrumentation is used to detect various undefined
|
||||
behaviours in runtime. Various types of checks may be enabled
|
||||
via boot parameter ubsan_handle (see: Documentation/ubsan.txt).
|
||||
|
||||
config UBSAN_SANITIZE_ALL
|
||||
bool "Enable instrumentation for the entire kernel"
|
||||
depends on UBSAN
|
||||
depends on ARCH_HAS_UBSAN_SANITIZE_ALL
|
||||
default y
|
||||
help
|
||||
This option activates instrumentation for the entire kernel.
|
||||
If you don't enable this option, you have to explicitly specify
|
||||
UBSAN_SANITIZE := y for the files/directories you want to check for UB.
|
||||
|
||||
config UBSAN_ALIGNMENT
|
||||
bool "Enable checking of pointers alignment"
|
||||
depends on UBSAN
|
||||
default y if !HAVE_EFFICIENT_UNALIGNED_ACCESS
|
||||
help
|
||||
This option enables detection of unaligned memory accesses.
|
||||
Enabling this option on architectures that support unalligned
|
||||
accesses may produce a lot of false positives.
|
|
@ -209,3 +209,6 @@ quiet_cmd_build_OID_registry = GEN $@
|
|||
clean-files += oid_registry_data.c
|
||||
|
||||
obj-$(CONFIG_UCS2_STRING) += ucs2_string.o
|
||||
obj-$(CONFIG_UBSAN) += ubsan.o
|
||||
|
||||
UBSAN_SANITIZE_ubsan.o := n
|
||||
|
|
456
lib/ubsan.c
Normal file
456
lib/ubsan.c
Normal file
|
@ -0,0 +1,456 @@
|
|||
/*
|
||||
* UBSAN error reporting functions
|
||||
*
|
||||
* Copyright (c) 2014 Samsung Electronics Co., Ltd.
|
||||
* Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
*/
|
||||
|
||||
#include <linux/bitops.h>
|
||||
#include <linux/bug.h>
|
||||
#include <linux/ctype.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/types.h>
|
||||
#include <linux/sched.h>
|
||||
|
||||
#include "ubsan.h"
|
||||
|
||||
const char *type_check_kinds[] = {
|
||||
"load of",
|
||||
"store to",
|
||||
"reference binding to",
|
||||
"member access within",
|
||||
"member call on",
|
||||
"constructor call on",
|
||||
"downcast of",
|
||||
"downcast of"
|
||||
};
|
||||
|
||||
#define REPORTED_BIT 31
|
||||
|
||||
#if (BITS_PER_LONG == 64) && defined(__BIG_ENDIAN)
|
||||
#define COLUMN_MASK (~(1U << REPORTED_BIT))
|
||||
#define LINE_MASK (~0U)
|
||||
#else
|
||||
#define COLUMN_MASK (~0U)
|
||||
#define LINE_MASK (~(1U << REPORTED_BIT))
|
||||
#endif
|
||||
|
||||
#define VALUE_LENGTH 40
|
||||
|
||||
static bool was_reported(struct source_location *location)
|
||||
{
|
||||
return test_and_set_bit(REPORTED_BIT, &location->reported);
|
||||
}
|
||||
|
||||
static void print_source_location(const char *prefix,
|
||||
struct source_location *loc)
|
||||
{
|
||||
pr_err("%s %s:%d:%d\n", prefix, loc->file_name,
|
||||
loc->line & LINE_MASK, loc->column & COLUMN_MASK);
|
||||
}
|
||||
|
||||
static bool suppress_report(struct source_location *loc)
|
||||
{
|
||||
return current->in_ubsan || was_reported(loc);
|
||||
}
|
||||
|
||||
static bool type_is_int(struct type_descriptor *type)
|
||||
{
|
||||
return type->type_kind == type_kind_int;
|
||||
}
|
||||
|
||||
static bool type_is_signed(struct type_descriptor *type)
|
||||
{
|
||||
WARN_ON(!type_is_int(type));
|
||||
return type->type_info & 1;
|
||||
}
|
||||
|
||||
static unsigned type_bit_width(struct type_descriptor *type)
|
||||
{
|
||||
return 1 << (type->type_info >> 1);
|
||||
}
|
||||
|
||||
static bool is_inline_int(struct type_descriptor *type)
|
||||
{
|
||||
unsigned inline_bits = sizeof(unsigned long)*8;
|
||||
unsigned bits = type_bit_width(type);
|
||||
|
||||
WARN_ON(!type_is_int(type));
|
||||
|
||||
return bits <= inline_bits;
|
||||
}
|
||||
|
||||
static s_max get_signed_val(struct type_descriptor *type, unsigned long val)
|
||||
{
|
||||
if (is_inline_int(type)) {
|
||||
unsigned extra_bits = sizeof(s_max)*8 - type_bit_width(type);
|
||||
return ((s_max)val) << extra_bits >> extra_bits;
|
||||
}
|
||||
|
||||
if (type_bit_width(type) == 64)
|
||||
return *(s64 *)val;
|
||||
|
||||
return *(s_max *)val;
|
||||
}
|
||||
|
||||
static bool val_is_negative(struct type_descriptor *type, unsigned long val)
|
||||
{
|
||||
return type_is_signed(type) && get_signed_val(type, val) < 0;
|
||||
}
|
||||
|
||||
static u_max get_unsigned_val(struct type_descriptor *type, unsigned long val)
|
||||
{
|
||||
if (is_inline_int(type))
|
||||
return val;
|
||||
|
||||
if (type_bit_width(type) == 64)
|
||||
return *(u64 *)val;
|
||||
|
||||
return *(u_max *)val;
|
||||
}
|
||||
|
||||
static void val_to_string(char *str, size_t size, struct type_descriptor *type,
|
||||
unsigned long value)
|
||||
{
|
||||
if (type_is_int(type)) {
|
||||
if (type_bit_width(type) == 128) {
|
||||
#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
|
||||
u_max val = get_unsigned_val(type, value);
|
||||
|
||||
scnprintf(str, size, "0x%08x%08x%08x%08x",
|
||||
(u32)(val >> 96),
|
||||
(u32)(val >> 64),
|
||||
(u32)(val >> 32),
|
||||
(u32)(val));
|
||||
#else
|
||||
WARN_ON(1);
|
||||
#endif
|
||||
} else if (type_is_signed(type)) {
|
||||
scnprintf(str, size, "%lld",
|
||||
(s64)get_signed_val(type, value));
|
||||
} else {
|
||||
scnprintf(str, size, "%llu",
|
||||
(u64)get_unsigned_val(type, value));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
static bool location_is_valid(struct source_location *loc)
|
||||
{
|
||||
return loc->file_name != NULL;
|
||||
}
|
||||
|
||||
static DEFINE_SPINLOCK(report_lock);
|
||||
|
||||
static void ubsan_prologue(struct source_location *location,
|
||||
unsigned long *flags)
|
||||
{
|
||||
current->in_ubsan++;
|
||||
spin_lock_irqsave(&report_lock, *flags);
|
||||
|
||||
pr_err("========================================"
|
||||
"========================================\n");
|
||||
print_source_location("UBSAN: Undefined behaviour in", location);
|
||||
}
|
||||
|
||||
static void ubsan_epilogue(unsigned long *flags)
|
||||
{
|
||||
dump_stack();
|
||||
pr_err("========================================"
|
||||
"========================================\n");
|
||||
spin_unlock_irqrestore(&report_lock, *flags);
|
||||
current->in_ubsan--;
|
||||
}
|
||||
|
||||
static void handle_overflow(struct overflow_data *data, unsigned long lhs,
|
||||
unsigned long rhs, char op)
|
||||
{
|
||||
|
||||
struct type_descriptor *type = data->type;
|
||||
unsigned long flags;
|
||||
char lhs_val_str[VALUE_LENGTH];
|
||||
char rhs_val_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(lhs_val_str, sizeof(lhs_val_str), type, lhs);
|
||||
val_to_string(rhs_val_str, sizeof(rhs_val_str), type, rhs);
|
||||
pr_err("%s integer overflow:\n",
|
||||
type_is_signed(type) ? "signed" : "unsigned");
|
||||
pr_err("%s %c %s cannot be represented in type %s\n",
|
||||
lhs_val_str,
|
||||
op,
|
||||
rhs_val_str,
|
||||
type->type_name);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
|
||||
void __ubsan_handle_add_overflow(struct overflow_data *data,
|
||||
unsigned long lhs,
|
||||
unsigned long rhs)
|
||||
{
|
||||
|
||||
handle_overflow(data, lhs, rhs, '+');
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_add_overflow);
|
||||
|
||||
void __ubsan_handle_sub_overflow(struct overflow_data *data,
|
||||
unsigned long lhs,
|
||||
unsigned long rhs)
|
||||
{
|
||||
handle_overflow(data, lhs, rhs, '-');
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_sub_overflow);
|
||||
|
||||
void __ubsan_handle_mul_overflow(struct overflow_data *data,
|
||||
unsigned long lhs,
|
||||
unsigned long rhs)
|
||||
{
|
||||
handle_overflow(data, lhs, rhs, '*');
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_mul_overflow);
|
||||
|
||||
void __ubsan_handle_negate_overflow(struct overflow_data *data,
|
||||
unsigned long old_val)
|
||||
{
|
||||
unsigned long flags;
|
||||
char old_val_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(old_val_str, sizeof(old_val_str), data->type, old_val);
|
||||
|
||||
pr_err("negation of %s cannot be represented in type %s:\n",
|
||||
old_val_str, data->type->type_name);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_negate_overflow);
|
||||
|
||||
|
||||
void __ubsan_handle_divrem_overflow(struct overflow_data *data,
|
||||
unsigned long lhs,
|
||||
unsigned long rhs)
|
||||
{
|
||||
unsigned long flags;
|
||||
char rhs_val_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(rhs_val_str, sizeof(rhs_val_str), data->type, rhs);
|
||||
|
||||
if (type_is_signed(data->type) && get_signed_val(data->type, rhs) == -1)
|
||||
pr_err("division of %s by -1 cannot be represented in type %s\n",
|
||||
rhs_val_str, data->type->type_name);
|
||||
else
|
||||
pr_err("division by zero\n");
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_divrem_overflow);
|
||||
|
||||
static void handle_null_ptr_deref(struct type_mismatch_data *data)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
pr_err("%s null pointer of type %s\n",
|
||||
type_check_kinds[data->type_check_kind],
|
||||
data->type->type_name);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
|
||||
static void handle_missaligned_access(struct type_mismatch_data *data,
|
||||
unsigned long ptr)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
pr_err("%s misaligned address %p for type %s\n",
|
||||
type_check_kinds[data->type_check_kind],
|
||||
(void *)ptr, data->type->type_name);
|
||||
pr_err("which requires %ld byte alignment\n", data->alignment);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
|
||||
static void handle_object_size_mismatch(struct type_mismatch_data *data,
|
||||
unsigned long ptr)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
pr_err("%s address %pk with insufficient space\n",
|
||||
type_check_kinds[data->type_check_kind],
|
||||
(void *) ptr);
|
||||
pr_err("for an object of type %s\n", data->type->type_name);
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
|
||||
void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
|
||||
unsigned long ptr)
|
||||
{
|
||||
|
||||
if (!ptr)
|
||||
handle_null_ptr_deref(data);
|
||||
else if (data->alignment && !IS_ALIGNED(ptr, data->alignment))
|
||||
handle_missaligned_access(data, ptr);
|
||||
else
|
||||
handle_object_size_mismatch(data, ptr);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_type_mismatch);
|
||||
|
||||
void __ubsan_handle_nonnull_return(struct nonnull_return_data *data)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
pr_err("null pointer returned from function declared to never return null\n");
|
||||
|
||||
if (location_is_valid(&data->attr_location))
|
||||
print_source_location("returns_nonnull attribute specified in",
|
||||
&data->attr_location);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_nonnull_return);
|
||||
|
||||
void __ubsan_handle_vla_bound_not_positive(struct vla_bound_data *data,
|
||||
unsigned long bound)
|
||||
{
|
||||
unsigned long flags;
|
||||
char bound_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(bound_str, sizeof(bound_str), data->type, bound);
|
||||
pr_err("variable length array bound value %s <= 0\n", bound_str);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_vla_bound_not_positive);
|
||||
|
||||
void __ubsan_handle_out_of_bounds(struct out_of_bounds_data *data,
|
||||
unsigned long index)
|
||||
{
|
||||
unsigned long flags;
|
||||
char index_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(index_str, sizeof(index_str), data->index_type, index);
|
||||
pr_err("index %s is out of range for type %s\n", index_str,
|
||||
data->array_type->type_name);
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_out_of_bounds);
|
||||
|
||||
void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
|
||||
unsigned long lhs, unsigned long rhs)
|
||||
{
|
||||
unsigned long flags;
|
||||
struct type_descriptor *rhs_type = data->rhs_type;
|
||||
struct type_descriptor *lhs_type = data->lhs_type;
|
||||
char rhs_str[VALUE_LENGTH];
|
||||
char lhs_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(rhs_str, sizeof(rhs_str), rhs_type, rhs);
|
||||
val_to_string(lhs_str, sizeof(lhs_str), lhs_type, lhs);
|
||||
|
||||
if (val_is_negative(rhs_type, rhs))
|
||||
pr_err("shift exponent %s is negative\n", rhs_str);
|
||||
|
||||
else if (get_unsigned_val(rhs_type, rhs) >=
|
||||
type_bit_width(lhs_type))
|
||||
pr_err("shift exponent %s is too large for %u-bit type %s\n",
|
||||
rhs_str,
|
||||
type_bit_width(lhs_type),
|
||||
lhs_type->type_name);
|
||||
else if (val_is_negative(lhs_type, lhs))
|
||||
pr_err("left shift of negative value %s\n",
|
||||
lhs_str);
|
||||
else
|
||||
pr_err("left shift of %s by %s places cannot be"
|
||||
" represented in type %s\n",
|
||||
lhs_str, rhs_str,
|
||||
lhs_type->type_name);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds);
|
||||
|
||||
|
||||
void __noreturn
|
||||
__ubsan_handle_builtin_unreachable(struct unreachable_data *data)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
pr_err("calling __builtin_unreachable()\n");
|
||||
ubsan_epilogue(&flags);
|
||||
panic("can't return from __builtin_unreachable()");
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);
|
||||
|
||||
void __ubsan_handle_load_invalid_value(struct invalid_value_data *data,
|
||||
unsigned long val)
|
||||
{
|
||||
unsigned long flags;
|
||||
char val_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(val_str, sizeof(val_str), data->type, val);
|
||||
|
||||
pr_err("load of value %s is not a valid value for type %s\n",
|
||||
val_str, data->type->type_name);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
|
84
lib/ubsan.h
Normal file
84
lib/ubsan.h
Normal file
|
@ -0,0 +1,84 @@
|
|||
#ifndef _LIB_UBSAN_H
|
||||
#define _LIB_UBSAN_H
|
||||
|
||||
enum {
|
||||
type_kind_int = 0,
|
||||
type_kind_float = 1,
|
||||
type_unknown = 0xffff
|
||||
};
|
||||
|
||||
struct type_descriptor {
|
||||
u16 type_kind;
|
||||
u16 type_info;
|
||||
char type_name[1];
|
||||
};
|
||||
|
||||
struct source_location {
|
||||
const char *file_name;
|
||||
union {
|
||||
unsigned long reported;
|
||||
struct {
|
||||
u32 line;
|
||||
u32 column;
|
||||
};
|
||||
};
|
||||
};
|
||||
|
||||
struct overflow_data {
|
||||
struct source_location location;
|
||||
struct type_descriptor *type;
|
||||
};
|
||||
|
||||
struct type_mismatch_data {
|
||||
struct source_location location;
|
||||
struct type_descriptor *type;
|
||||
unsigned long alignment;
|
||||
unsigned char type_check_kind;
|
||||
};
|
||||
|
||||
struct nonnull_arg_data {
|
||||
struct source_location location;
|
||||
struct source_location attr_location;
|
||||
int arg_index;
|
||||
};
|
||||
|
||||
struct nonnull_return_data {
|
||||
struct source_location location;
|
||||
struct source_location attr_location;
|
||||
};
|
||||
|
||||
struct vla_bound_data {
|
||||
struct source_location location;
|
||||
struct type_descriptor *type;
|
||||
};
|
||||
|
||||
struct out_of_bounds_data {
|
||||
struct source_location location;
|
||||
struct type_descriptor *array_type;
|
||||
struct type_descriptor *index_type;
|
||||
};
|
||||
|
||||
struct shift_out_of_bounds_data {
|
||||
struct source_location location;
|
||||
struct type_descriptor *lhs_type;
|
||||
struct type_descriptor *rhs_type;
|
||||
};
|
||||
|
||||
struct unreachable_data {
|
||||
struct source_location location;
|
||||
};
|
||||
|
||||
struct invalid_value_data {
|
||||
struct source_location location;
|
||||
struct type_descriptor *type;
|
||||
};
|
||||
|
||||
#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
|
||||
typedef __int128 s_max;
|
||||
typedef unsigned __int128 u_max;
|
||||
#else
|
||||
typedef s64 s_max;
|
||||
typedef u64 u_max;
|
||||
#endif
|
||||
|
||||
#endif
|
|
@ -1,4 +1,5 @@
|
|||
KASAN_SANITIZE := n
|
||||
UBSAN_SANITIZE_kasan.o := n
|
||||
|
||||
CFLAGS_REMOVE_kasan.o = -pg
|
||||
# Function splitter causes unnecessary splits in __asan_load1/__asan_store1
|
||||
|
|
|
@ -130,6 +130,12 @@ _c_flags += $(if $(patsubst n%,, \
|
|||
$(CFLAGS_KASAN))
|
||||
endif
|
||||
|
||||
ifeq ($(CONFIG_UBSAN),y)
|
||||
_c_flags += $(if $(patsubst n%,, \
|
||||
$(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
|
||||
$(CFLAGS_UBSAN))
|
||||
endif
|
||||
|
||||
# If building the kernel in a separate objtree expand all occurrences
|
||||
# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
|
||||
|
||||
|
|
17
scripts/Makefile.ubsan
Normal file
17
scripts/Makefile.ubsan
Normal file
|
@ -0,0 +1,17 @@
|
|||
ifdef CONFIG_UBSAN
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=shift)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=integer-divide-by-zero)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=unreachable)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=vla-bound)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=null)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=signed-integer-overflow)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=bounds)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=object-size)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=returns-nonnull-attribute)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=bool)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=enum)
|
||||
|
||||
ifdef CONFIG_UBSAN_ALIGNMENT
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment)
|
||||
endif
|
||||
endif
|
Loading…
Reference in a new issue