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// Copyright 2017 syzkaller project authors. All rights reserved.
// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
package linux
import (
"runtime"
"github.com/google/syzkaller/prog"
"github.com/google/syzkaller/sys/targets"
)
/*
func init() {
prog.RegisterTarget(gen.Target_amd64, initTarget)
prog.RegisterTarget(gen.Target_386, initTarget)
prog.RegisterTarget(gen.Target_arm64, initTarget)
prog.RegisterTarget(gen.Target_arm, initTarget)
prog.RegisterTarget(gen.Target_ppc64le, initTarget)
}
*/
func InitTarget(target *prog.Target) {
arch := &arch{
unix: targets.MakeUnixSanitizer(target),
clockGettimeSyscall: target.SyscallMap["clock_gettime"],
SYSLOG_ACTION_CONSOLE_OFF: target.ConstMap["SYSLOG_ACTION_CONSOLE_OFF"],
SYSLOG_ACTION_CONSOLE_ON: target.ConstMap["SYSLOG_ACTION_CONSOLE_ON"],
SYSLOG_ACTION_SIZE_UNREAD: target.ConstMap["SYSLOG_ACTION_SIZE_UNREAD"],
FIFREEZE: target.ConstMap["FIFREEZE"],
FITHAW: target.ConstMap["FITHAW"],
PTRACE_TRACEME: target.ConstMap["PTRACE_TRACEME"],
CLOCK_REALTIME: target.ConstMap["CLOCK_REALTIME"],
ARCH_SET_FS: target.ConstMap["ARCH_SET_FS"],
ARCH_SET_GS: target.ConstMap["ARCH_SET_GS"],
AF_NFC: target.ConstMap["AF_NFC"],
AF_LLC: target.ConstMap["AF_LLC"],
AF_BLUETOOTH: target.ConstMap["AF_BLUETOOTH"],
}
target.MakeMmap = targets.MakePosixMmap(target)
target.SanitizeCall = arch.sanitizeCall
target.SpecialTypes = map[string]func(g *prog.Gen, typ prog.Type, old prog.Arg) (
prog.Arg, []*prog.Call){
"timespec": arch.generateTimespec,
"timeval": arch.generateTimespec,
"sockaddr_alg": arch.generateSockaddrAlg,
"alg_name": arch.generateAlgName,
"alg_aead_name": arch.generateAlgAeadName,
"alg_hash_name": arch.generateAlgHashName,
"alg_blkcipher_name": arch.generateAlgBlkcipherhName,
"ipt_replace": arch.generateIptables,
"ip6t_replace": arch.generateIptables,
"arpt_replace": arch.generateArptables,
"ebt_replace": arch.generateEbtables,
}
target.StringDictionary = stringDictionary
if target.Arch == runtime.GOARCH {
KCOV_INIT_TRACE = uintptr(target.ConstMap["KCOV_INIT_TRACE"])
KCOV_ENABLE = uintptr(target.ConstMap["KCOV_ENABLE"])
KCOV_DISABLE = uintptr(target.ConstMap["KCOV_DISABLE"])
KCOV_TRACE_CMP = uintptr(target.ConstMap["KCOV_TRACE_CMP"])
}
}
var (
// This should not be here, but for now we expose this for syz-fuzzer.
KCOV_INIT_TRACE uintptr
KCOV_ENABLE uintptr
KCOV_DISABLE uintptr
KCOV_TRACE_CMP uintptr
// TODO(dvyukov): get rid of this, this must be in descriptions.
stringDictionary = []string{"user", "keyring", "trusted", "system", "security", "selinux",
"posix_acl_access", "mime_type", "md5sum", "nodev", "self",
"bdev", "proc", "cgroup", "cpuset",
"lo", "eth0", "eth1", "em0", "em1", "wlan0", "wlan1", "ppp0", "ppp1",
"vboxnet0", "vboxnet1", "vmnet0", "vmnet1", "GPL"}
)
type arch struct {
unix *targets.UnixSanitizer
clockGettimeSyscall *prog.Syscall
SYSLOG_ACTION_CONSOLE_OFF uint64
SYSLOG_ACTION_CONSOLE_ON uint64
SYSLOG_ACTION_SIZE_UNREAD uint64
FIFREEZE uint64
FITHAW uint64
PTRACE_TRACEME uint64
CLOCK_REALTIME uint64
ARCH_SET_FS uint64
ARCH_SET_GS uint64
AF_NFC uint64
AF_LLC uint64
AF_BLUETOOTH uint64
}
func (arch *arch) sanitizeCall(c *prog.Call) {
arch.unix.SanitizeCall(c)
switch c.Meta.CallName {
case "syslog":
cmd := c.Args[0].(*prog.ConstArg)
cmd.Val = uint64(uint32(cmd.Val))
// These disable console output, but we need it.
if cmd.Val == arch.SYSLOG_ACTION_CONSOLE_OFF || cmd.Val == arch.SYSLOG_ACTION_CONSOLE_ON {
cmd.Val = arch.SYSLOG_ACTION_SIZE_UNREAD
}
case "ioctl":
cmd := c.Args[1].(*prog.ConstArg)
// Freeze kills machine. Though, it is an interesting functions,
// so we need to test it somehow.
// TODO: not required if executor drops privileges.
if uint64(uint32(cmd.Val)) == arch.FIFREEZE {
cmd.Val = arch.FITHAW
}
case "ptrace":
req := c.Args[0].(*prog.ConstArg)
// PTRACE_TRACEME leads to unkillable processes, see:
// https://groups.google.com/forum/#!topic/syzkaller/uGzwvhlCXAw
if req.Val == arch.PTRACE_TRACEME {
req.Val = ^uint64(0)
}
case "arch_prctl":
// fs holds address of tls, if a program messes it at least signal
// handling will break. This also allows a program to do writes
// at arbitrary addresses, which usually leads to machine outbreak.
cmd := c.Args[0].(*prog.ConstArg)
if uint64(uint32(cmd.Val)) == arch.ARCH_SET_FS {
cmd.Val = arch.ARCH_SET_GS
}
case "syz_init_net_socket":
// Don't let it mess with arbitrary sockets in init namespace.
family := c.Args[0].(*prog.ConstArg)
switch uint64(uint32(family.Val)) {
case arch.AF_NFC, arch.AF_LLC, arch.AF_BLUETOOTH:
default:
family.Val = ^uint64(0)
}
}
switch c.Meta.Name {
case "setsockopt$EBT_SO_SET_ENTRIES":
arch.sanitizeEbtables(c)
}
}
func (arch *arch) generateTimespec(g *prog.Gen, typ0 prog.Type, old prog.Arg) (arg prog.Arg, calls []*prog.Call) {
typ := typ0.(*prog.StructType)
// We need to generate timespec/timeval that are either
// (1) definitely in the past, or
// (2) definitely in unreachable fututre, or
// (3) few ms ahead of now.
// Note: timespec/timeval can be absolute or relative to now.
// Note: executor has blocking syscall timeout of 20ms,
// so we generate both 10ms and 30ms.
usec := typ.Name() == "timeval"
switch {
case g.NOutOf(1, 4):
// Now for relative, past for absolute.
arg = prog.MakeGroupArg(typ, []prog.Arg{
prog.MakeResultArg(typ.Fields[0], nil, 0),
prog.MakeResultArg(typ.Fields[1], nil, 0),
})
case g.NOutOf(1, 3):
// Few ms ahead for relative, past for absolute
nsec := uint64(10 * 1e6)
if g.NOutOf(1, 2) {
nsec = 30 * 1e6
}
if usec {
nsec /= 1e3
}
arg = prog.MakeGroupArg(typ, []prog.Arg{
prog.MakeResultArg(typ.Fields[0], nil, 0),
prog.MakeResultArg(typ.Fields[1], nil, nsec),
})
case g.NOutOf(1, 2):
// Unreachable fututre for both relative and absolute
arg = prog.MakeGroupArg(typ, []prog.Arg{
prog.MakeResultArg(typ.Fields[0], nil, 2e9),
prog.MakeResultArg(typ.Fields[1], nil, 0),
})
default:
// Few ms ahead for absolute.
meta := arch.clockGettimeSyscall
ptrArgType := meta.Args[1].(*prog.PtrType)
argType := ptrArgType.Type.(*prog.StructType)
tp := prog.MakeGroupArg(argType, []prog.Arg{
prog.MakeResultArg(argType.Fields[0], nil, 0),
prog.MakeResultArg(argType.Fields[1], nil, 0),
})
var tpaddr prog.Arg
tpaddr, calls = g.Alloc(ptrArgType, tp)
gettime := &prog.Call{
Meta: meta,
Args: []prog.Arg{
prog.MakeConstArg(meta.Args[0], arch.CLOCK_REALTIME),
tpaddr,
},
Ret: prog.MakeReturnArg(meta.Ret),
}
calls = append(calls, gettime)
sec := prog.MakeResultArg(typ.Fields[0], tp.Inner[0].(*prog.ResultArg), 0)
nsec := prog.MakeResultArg(typ.Fields[1], tp.Inner[1].(*prog.ResultArg), 0)
msec := uint64(10)
if g.NOutOf(1, 2) {
msec = 30
}
if usec {
nsec.OpDiv = 1e3
nsec.OpAdd = msec * 1e3
} else {
nsec.OpAdd = msec * 1e6
}
arg = prog.MakeGroupArg(typ, []prog.Arg{sec, nsec})
}
return
}
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