mirror of
https://github.com/netbirdio/gvisor.git
synced 2026-05-22 17:12:49 -07:00
Restrict ptrace(2) according to the default configurations of the YAMA security module (mode 1), which is a common default among various Linux distributions. The new access checks only permit the tracer to proceed if one of the following conditions is met: a) The tracer is already attached to the tracee. b) The target is a descendant of the tracer. c) The target has explicitly given permission to the tracer through the PR_SET_PTRACER prctl. d) The tracer has CAP_SYS_PTRACE. See security/yama/yama_lsm.c for more details. Note that these checks are added to CanTrace, which is checked for PTRACE_ATTACH as well as some other operations, e.g., checking a process' memory layout through /proc/[pid]/mem. Since this patch adds restrictions to ptrace, it may break compatibility for applications run by non-root users that, for instance, rely on being able to trace processes that are not descended from the tracer (e.g., `gdb -p`). YAMA restrictions can be turned off by setting /proc/sys/kernel/yama/ptrace_scope to 0, or exceptions can be made on a per-process basis with the PR_SET_PTRACER prctl. Reported-by: syzbot+622822d8bca08c99e8c8@syzkaller.appspotmail.com PiperOrigin-RevId: 359237723
96 lines
3.0 KiB
Go
96 lines
3.0 KiB
Go
// Copyright 2018 The gVisor Authors.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package linux
|
|
|
|
// ptrace commands from include/uapi/linux/ptrace.h.
|
|
const (
|
|
PTRACE_TRACEME = 0
|
|
PTRACE_PEEKTEXT = 1
|
|
PTRACE_PEEKDATA = 2
|
|
PTRACE_PEEKUSR = 3
|
|
PTRACE_POKETEXT = 4
|
|
PTRACE_POKEDATA = 5
|
|
PTRACE_POKEUSR = 6
|
|
PTRACE_CONT = 7
|
|
PTRACE_KILL = 8
|
|
PTRACE_SINGLESTEP = 9
|
|
PTRACE_ATTACH = 16
|
|
PTRACE_DETACH = 17
|
|
PTRACE_SYSCALL = 24
|
|
PTRACE_SETOPTIONS = 0x4200
|
|
PTRACE_GETEVENTMSG = 0x4201
|
|
PTRACE_GETSIGINFO = 0x4202
|
|
PTRACE_SETSIGINFO = 0x4203
|
|
PTRACE_GETREGSET = 0x4204
|
|
PTRACE_SETREGSET = 0x4205
|
|
PTRACE_SEIZE = 0x4206
|
|
PTRACE_INTERRUPT = 0x4207
|
|
PTRACE_LISTEN = 0x4208
|
|
PTRACE_PEEKSIGINFO = 0x4209
|
|
PTRACE_GETSIGMASK = 0x420a
|
|
PTRACE_SETSIGMASK = 0x420b
|
|
PTRACE_SECCOMP_GET_FILTER = 0x420c
|
|
PTRACE_SECCOMP_GET_METADATA = 0x420d
|
|
)
|
|
|
|
// ptrace commands from arch/x86/include/uapi/asm/ptrace-abi.h.
|
|
const (
|
|
PTRACE_GETREGS = 12
|
|
PTRACE_SETREGS = 13
|
|
PTRACE_GETFPREGS = 14
|
|
PTRACE_SETFPREGS = 15
|
|
PTRACE_GETFPXREGS = 18
|
|
PTRACE_SETFPXREGS = 19
|
|
PTRACE_OLDSETOPTIONS = 21
|
|
PTRACE_GET_THREAD_AREA = 25
|
|
PTRACE_SET_THREAD_AREA = 26
|
|
PTRACE_ARCH_PRCTL = 30
|
|
PTRACE_SYSEMU = 31
|
|
PTRACE_SYSEMU_SINGLESTEP = 32
|
|
PTRACE_SINGLEBLOCK = 33
|
|
)
|
|
|
|
// ptrace event codes from include/uapi/linux/ptrace.h.
|
|
const (
|
|
PTRACE_EVENT_FORK = 1
|
|
PTRACE_EVENT_VFORK = 2
|
|
PTRACE_EVENT_CLONE = 3
|
|
PTRACE_EVENT_EXEC = 4
|
|
PTRACE_EVENT_VFORK_DONE = 5
|
|
PTRACE_EVENT_EXIT = 6
|
|
PTRACE_EVENT_SECCOMP = 7
|
|
PTRACE_EVENT_STOP = 128
|
|
)
|
|
|
|
// PTRACE_SETOPTIONS options from include/uapi/linux/ptrace.h.
|
|
const (
|
|
PTRACE_O_TRACESYSGOOD = 1
|
|
PTRACE_O_TRACEFORK = 1 << PTRACE_EVENT_FORK
|
|
PTRACE_O_TRACEVFORK = 1 << PTRACE_EVENT_VFORK
|
|
PTRACE_O_TRACECLONE = 1 << PTRACE_EVENT_CLONE
|
|
PTRACE_O_TRACEEXEC = 1 << PTRACE_EVENT_EXEC
|
|
PTRACE_O_TRACEVFORKDONE = 1 << PTRACE_EVENT_VFORK_DONE
|
|
PTRACE_O_TRACEEXIT = 1 << PTRACE_EVENT_EXIT
|
|
PTRACE_O_TRACESECCOMP = 1 << PTRACE_EVENT_SECCOMP
|
|
PTRACE_O_EXITKILL = 1 << 20
|
|
PTRACE_O_SUSPEND_SECCOMP = 1 << 21
|
|
)
|
|
|
|
// YAMA ptrace_scope levels from security/yama/yama_lsm.c.
|
|
const (
|
|
YAMA_SCOPE_DISABLED = 0
|
|
YAMA_SCOPE_RELATIONAL = 1
|
|
)
|